Throttle Bodies

[tassie_euro_mk1]

Hey guys im thinking of going down the throttle bodies route for my mk1 project. something a little bit different. not sure what engine im looking at yet. Either a 2L 8v or 2L 16v.

Can anyone please point me out to some good websites about them? Especially for golf engine applications.

Or should I forget them completely. I dont want to go down the forced induction route because it seems to be the norm (no offence to anyone :))


cheers guys
Eric

[velly_16v_cab]

http://www.badger5.co.uk/

iTB's, you will be talking 190BHP+ from a good 2.0 16v or abut 170bhp from and 8v cross flow.

They are great but setting up can be a pain in the butt!

Someone before has run them (i think it was valver or someone) on a seat ibiza, getting it tune was a pain as i remember.

easier and cheaper to run twin 45's carbs and about the same power (my mates mk1 2.1 16v twin 48's was 210bhp!)

i would look into your managment and tuning options first to see if you can go iTB's.

There is some threads in the members motors on CGTI forum of guys with iTB's

[evorobin]

http://forums.vwvortex.com/zerothread?id=3645847

Let the moths out champ :D

[Water Boy]

Mate if u r going ITB's check out http://www.efihardware.com/efi_throttle.html

That is what we run on the 16v

or gsxr1000 r compact and cheap i beleive

[tassie_euro_mk1]

thanks guys.

would twin 45's use more fuel than ITB's? or about the same?


For the VW 2L 16V engine.
http://www.vwwatercooled.com.au/forums/images/imported/2008/05/DBVW-1.jpg
45mm throttle bodies which mount directly to the cylinder head.
A comprehensive kit is available from;
Badger5 Ltd., 57, Adelaide Gardens, Stonehouse, Gloucs, GL10 2PZ
Tel; (44) (0)1453 827936, Fax; (44) (0)870 0561360
Email; bill@Badger5.co.uk, Web; www.Badger5.co.uk

Engine application data

this is what im thinking about.

ill look into the gsxr1000 throttle bodies. would they be big enough though?

[velly_16v_cab]

your fuel will be pants with either of them!

i ran twin 40's webber carbs on my cab. it double the amount of fuel i was using.

but, fuel is cheap out here...so i wouldnt worry about that (but only having a 200 mile range was a killer tho lol)

[tassie_euro_mk1]

yea cool. well its not gonna be my daily driver anyway. Just an expensive toy lol.

[Valver.]

There's another thread on here somewhere and I posted a fair bit on it... probably a few pages back now.

Long and the short of it is, big money, or absolutely zero performance gain.

The fuel consumption is fine on anything but wide throttle openings: the minute you open it up, your tank is drained. ITBs will use a lot less fuel than carbs, but you'll go from a combined cycle of 8.5l/100km on a 2.0 16v, to about 14l/100km combined even with the ITBs.

[Jarred]

PM wabit abut bike carbs, quad 40's, and they're pretty gd i've heard

http://hausbrauen.blogspot.com/2006/03/bike-carbs.html

check that site, gd read. carbs are als0 simpler with tuning (i think) less wires anyways

[static1800]

Will try and dig up the thread Valver, Im tossing up whether to use ITB's or not. A mate of mine has some off of a Ninja I am planning to look at, it's that or my mate has a spare GT25 turbo from a CA18 engine.....

[Valver.]

I can reel off pages of crap about this, but there's no point. It really comes down to whether or not you have the funds to build a race motor with the volumetric efficiency to use (... or need) the extra intake potenial.

When you get the motor to this point, it's so peaky that you also need to address the gearbox, which isn't just a matter of changing the ring and pinion, as this slaughters any notion of top speed, it means swapping in a whole new gearset.

It goes from a $5000 exercise for a nice sound to a $30,000 exercise for a well-performing engine and driveline.

I hate turbo cars, but I've built one, as VW engines don't perform well without a turbo, and I like VWs...

[tassie_euro_mk1]

mmm maybe theyre not the go. I just thought they would of been a good alternative to the twin side draught webbers.

ah well I have time to ponder these things. Thanks for the input guys. I appreciate it.

I mean I was thinking of having an engine with power at around 170hp - 200hp???

[Valver.]

Having been there and done that, I'd spend my money on high class headwork and cams and a good value ECU, like an Autronic SMC. You can make a very torquey ~185hp 2.0 16v on standard induction due to the long stroke of these engines. They don't rev near as well as a Honda because of this, but they develop torque nicely and still go to high 7k rpm safely with a few tweaks :)

Other option is KR or PL 1.9 conversion, if you want a better-revving setup.

11-11.5 compression is the ultimate for a street 16v too.

[Preen59]

mmm maybe theyre not the go. I just thought they would of been a good alternative to the twin side draught webbers.

ah well I have time to ponder these things. Thanks for the input guys. I appreciate it.

I mean I was thinking of having an engine with power at around 170hp - 200hp???

I'm building a 1.9 16v on twin 45 DCOEs. From what i've read and from talking to Techtonics Tuning, it should have about 200 or a bit more with the config i'm running.

The thing you have to remember is, ATMO horsepower is made with RPMs.

Horsepower is simply BMEP (brute mean effective pressure) times (x) RPM, so because you aren't filling the cylinder well to get a high BMEP, you have to rev the engine harder to produce more cycles in the same time span. That is why a forced induction engine will always have more torque.

The other issue is, the higher in the RPM range the engine makes its power, the crankier it will be at low RPM, and it will be very dull down low.

[GoLfMan]

I mean I was thinking of having an engine with power at around 170hp - 200hp???

that'd be easily accievable on a 16v on twin webers mate, just look at what Preens doing with his engine, that should put out over 200hp i recon

[Valver.]

My ABF that was in the blue Mk1 went really nicely with a good head, basic cams, extractors and a chip to suit. 112kW atw IIRC (will confirm tomorrow).

[Valver.]

that'd be easily accievable on a 16v on twin webers mate, just look at what Preens doing with his engine, that should put out over 200hp i recon


150kW is a lot harder to come by than US dynos show, believe me!!

[Preen59]

150kW is a lot harder to come by than US dynos show, believe me!!

Yeah thats very true. Also depends on the altitude its dyno'd at. Benny is getting new a wheel dyno in the new shop so when i get the donk done i'll tune it on there first up and get some figures, keeping in mind we're like 850m above sea level.

The other thing is too, have you ever driven a car with anywhere near 200hp and less than 900kg?

You're talking about a bloody fast street car. My mate has a 200hp atmo (2l pinto engine) Mk1 escort road registered race car, and it breaks traction in third gear at 50kmh with grooved Avons. It weighs about 900kg and its FAST. hits about 235 or a bit more into turn one at eastern creek, it's as quick as a modified EVO 7 in a straight line.

Heck, my little 1.7 donk was a quick little engine, and it only had (i reckon) about 130hp.

[peedman]

My mk1 with a stock kr with efi scared the cr ap out of me, i cant imagine even more power in it. One thing is for sure tho, it needs better brakes and i need bigger biceps to turn that steering!!

[DubSteve]

and i need bigger biceps to turn that steering!!

BUHAHAHAHA sorry but thats a classic call :D

[GoLfMan]

150kW is a lot harder to come by than US dynos show, believe me!!

of course it is in an NA 4 banger.... but more than achievable

[evorobin]

i need bigger biceps to turn that steering!!

I'm rife to tell weads to head to the gym but I feel like dennis the menace reading that j:

[velly_16v_cab]

most of the track guy in the uk run 2.0 16v's on k-jet. most of them putting out 180bhp+
a few are runningiTB's but not much gain (if any) over the k-jet boys...but they do sound nice lol

[Oneofthegreats]

that'd be easily accievable on a 16v on twin webers mate, just look at what Preens doing with his engine, that should put out over 200hp i recon

I've got to say Josh, if you reckon it's that easy to make 200hp from a NA 16V, everyone would be doing it incl. you.

It's much harder than you think.

For eg. Valver's ABF, with a bit of work, good part's & some coin thrown at it made near enough 200hp, but it only sound's easy!
I'm sure there was abit of tickling it here & there.

Before I start this, my comment's are for only VW's. V8's are totally different story. "There's no replacement for displacement"

Atmo power cost's way more to do than FI.
Also with NA power your limited by the amount of power you can get out of it, with the part's you throw at it, the person at the end of a die grinder & how deep your pocket's are.
Also how good the combination is too, cause alot of people do get it wrong & then your the one out of pocket.

That's why I like FI. Simple home made turbo kit can s#%t al over a big dollar NA engine, with heap's in reserve.

Eg. I could put a T3 60 trim .48ar turbo on my 8V with some Turbo K-Jet stuff off a Porsche, Volvo (which is only the fuel head & warm up reg. which I already have)etc., an intercooler on a stock engine with mild boost upto 11psi & make 200+hp with a nice broad torque curve. You won't get that with a highly tuned NA engine.

The reason why I don't, I'd rather spend the money on the chevy truck or the 20VT.

Also, alot of people bag the K-Jet. Why?? Cause they don't know the first thing about the system or how it work's.
Mercede's used it right upto the mid-late 90's from memory. Must be a real s#%t system.
The only down side I can think of. It look's like an octopus is having sex with your engine & it hate's water!
There's setup's out there pushing 300+hp on K-Jet VW engine's. You've just got to think outside the square & use what's available. eg. one bloke used a fuel system of a Merc V8 to fuel his 8V. You could use Porsche turbo stuff etc. K-Jet is K-jet. It's all work's the same, just with different fuelling capabilites.

Back on topic -
I reckon ITB's are a waist on a street/race car, even though a set of weber's are basically the same at a third the cost & without the electronic's. Alot of outlay on the part's, tuning etc for bugger all in return. Listen to the people who have gone down this path & they'll say the same.

I'd even go a holley over a set of ITB's, but not over a set of DCOE's.

[Water Boy]

Getting over 100kw at the wheels out of an NA 16v is the way to go :D

[Oneofthegreats]

Getting over 100kw at the wheels out of an NA 16v is the way to go :D

So why doesn't everyone do it.

It must be pretty easy if everyone say's so.

Just out of honest interest James.

How much hp is your dad's destroked 1.6L? 16V making & how hard has it been to make that power & what cost's have been involved?
I reckon there wouldn't be much change out of $10+k. The MoTec alone is should be over $4K tuned.

[Water Boy]

Mate only my Dad is stupid enough to do it... Its not easy and he says the only reason he has done it is for the enjoyment, the fun he has as he calls it "Bench Racing" He spent around 5 years plus most weekends out in our shed and going to different places sourcing bits n pieces...

My Dad says he had just as much fun getting the numbers on the dyno as hitting turn one flat out :D

And Tim money wise its not cheap so my Dad did it over a long period and apart from machining he did most himself... Luckily Dad has some good friends Mark and Ross who help out a heaps ECU wise...

Also my ol mans 2 mates are super keen and both helped heaps...

An all in afair most weekends... But it shall all pay off next weekend as there is a tune map and we r off to the Island for a state race :D

[Oneofthegreats]

I'm didn't mean it to come across to have a go at anyone & I'm sorry if it did come across like that.
I just get alittle peaved sometime's about some post's, on how easy it is to make these great power figures.
Like I said, if it is that easy, everyone would be doing it.

I just needed an example to show that it isn't as easy to make NA power as alot of people make out & your dad's 16V came to mind straight away as he'd told me some of the spec of the engine & what's he's done & been through to achieve it.

I can understand about the fun factor, as I cop alot of flack from my friend's about playing with VW's & how much money I spend on them.
I could have built a 632ci 750+hp PULP engine in my old black ute with the money I've spent on VW's. (Come to think of it, why didn't I???? :confused: I did want to do it at one stage :()

[Water Boy]

Mate im taking no offence at all... My ol boy shares your pain people talk about getting big numbers out of their cars ect but they dont actually understand its a load of work... My ol man has people ask why? He says bcuz he can, and its keeps him out of the pub :rolleyes:

Nah its not easy but if u wana give it a go hell year go for it...

Next step will be my engine and we have a few good bits for that aswell and the TDi we hope to build soon :D

Its all $$$$ though... I need to become rich :rolleyes:

[abreut]

Forced induction is the cheapest and easiest way to make power. My supercharged golf which was my first real experimentation with forced induction, made 112kw atw (exactly the same as your 16v valver!). That was with a $300 supercharger, an AGG 8v (worth very little), an $800 microtech, lots of bits and pieces from the wreckers and a crap-load of backyard fabrication. Seriously that setup was very cheap. And the torque! It was just ridiculous gobs of off-idle stump-pulling grunt.

Saying that I have a soft spot for NA and I do have more respect for the man who can get good power out of an NA setup - even though it might be 100hp down on some turbo setup. Horsepower really becomes a meaningless quantifier when you can make over 500whp on a 4 cyl but when you look at the power curve you have a ridiculously small high rpm powerband - useless! And when it comes on its like Dr Jekyl and Mr Hyde - totally non-linear. You can't call such an engine a good engine, not for anything where you actually need to regulate power delivery with a degree of skill. If you can make a great engine that propels that puppy when and how you need it, and it is actually fun to drive for whatever application you have chosen - then go for it!

[GoLfMan]

I've got to say Josh, if you reckon it's that easy to make 200hp from a NA 16V, everyone would be doing it incl. you.

It's much harder than you think..

no $hit its hard, and who says i wont do it, i may be a bit 'green' now but we all start somewhere, you were at this stage once too.

i think you misread my statement, of course its hard but its easily achievable as in you can easily achieve those figures with the right mods, its not like the engine isnt capable of it, just like V8's can easily achieve 800hp are we getting the picture yet???
As i said look at Preens engine, the amount of work into it and its going to be putting out circa 200hp, a good NA engine takes much more skill to build than a cheap turbo set up, wheres the sense of achievement in wacking on a hair dryer and winding up the boost?

Valvers engine that has been built specifically for big power turbo output takes skill, as do big power turbo 6's and 8's.

look at the first M3! 2.3L 4cyl quad throttle bodies, well designed engine and some crazy power, in race trim Jim Richards one was putting out 250kws!

its ok, have a crack mate i dont explain myself well sometimes :)
hopefully this time my statements will not be misconstrued.

this is not to be taken as an attack on anyone either, as this is a discussion and im just clearing up my point of view!!! ;)

[Jarred]

lif you want ITB's for the sounds and "cool" factor, which is a good enough reason (if you've got the cash) you may as well get bike carbs an 8V!

really. bike carbs even with a custom manifold, will be a hell of alot cheaper than ITB's + ECU + tuning. Also about half as much as (brand new) twin DCOE's.

Ultimately twin DCOE's aren't the most effective/effiecient way of making power, but shure, they sound good!

IMO (and correct me if my figures are wrong, Tim) but and 2.0L 8V with bike carbs (quad 40mm, sim to twin 40mm DCOE) with a decent cam (around the 276 region) a bit of head work, (read: more flow) and a few other bits and pieces, exhaust etc. and a proper tuning, and you could be looking at 130kw @ flywheel.

140HP in a 900(or less) kg car, for street purposes (mainly) perfect. you don't need more than that.

The money you save over buying a 16V and ITB, ECU etc, you can spend on actually getting better parts for an 8V (pistons, rods, machine work etc) (that's where the extra 20 or so kw come in)

Anyways, that's just my opinion. My next petrol engine will be pretty similar, except k-jet, "stage 1" headwork, lightened flywheel, 276 cam, balanced bottom and prolly a 1.8. I'm hoping for 100HP. That'll be enough for me :)

[GoLfMan]

I'm hoping for 100HP. That'll be enough for me :)

the stock 2L put out 100hp and the 1.8 GTi engines put out 100hp why not get a 2L or a GTi engine

[Jarred]

EDIT: I'm getting confused with my HP and KW.
I want about 100kw (fly), which is pretty moderate estimate. could get a bit more.

[Oneofthegreats]

IMO (and correct me if my figures are wrong, Tim) but and 2.0L 8V with bike carbs (quad 40mm, sim to twin 40mm DCOE) with a decent cam (around the 276 region) a bit of head work, (read: more flow) and a few other bits and pieces, exhaust etc. and a proper tuning, and you could be looking at 130kw @ flywheel.

140HP in a 900(or less) kg car, for street purposes (mainly) perfect. you don't need more than that.

My next petrol engine will be pretty similar, except k-jet, "stage 1" headwork, lightened flywheel, 276 cam, balanced bottom and prolly a 1.8. I'm hoping for 100HP. That'll be enough for me :)

I reckon to make 130 engine kw's, you'd need a 2L with at least 11+:1 CR, very good head work, you may even need a worked over cross flow ABA head to achieve the flow number's required, twin 45's & a big cam. Something over 288. 4-1 race header's with around 1 3/4"primary's & a full 2.25+" system.
That should see you to 180hp, but it won't play nice on the street.

I spoke with a bloke in the state's & he runs a Audi 2L with high compresion, solid lifter head, 306° cam in a car that weigh's 1600lbs (800kg's full weight) & runs 14.0's with 1.8 60fts!

Also take into account that a 3dr mk1 is roughly 850kg's dry. Then put fuel in it & yourself & see how light it is. It's not the 110hp in a 800kg car anymore.
When I weighed my 5dr beater with half a tank of fuel & me in it it was 1000kg's dead even, so 800kg's full weight is some pretty impressive number's.

Not all GTI engine's produce 100+hp either. Depend's on the engine code, as there aren't that many that make the full 112hp, nor have the compression.

With the mod's made to my old beater engine & the MPH it ran in the GTI full weight it's making roughly 105whp. A ET/HP calculator reckon's 143hp! But I don't think so. I'm thinking maybe 125hp.
Not bad with basic mod's & part's, but also not very impressive IMO.
I'll take you for a spin when I get it going & I can garantee you'll still want heaps more.
Once the auto is fitted I may fit a turbo later in the year.

Josh, I forgot to add I was talking about Valver's NA ABF.

I'm more of a street/race engine person, use the car as much as possible & not once a month.
Don't get me wrong, I love High HP NA low capacity engine's but then I don't because they aren't ideal street engine's & in most case are normally pig's to drive with massive cam's & idle's at 1300+rpm , that's why FI is a better option.
I'd have a mild turbo'd 8V over a berg racer engine anyday.

I understand that some think it's easy with a turbo, but it's not that easy. You still need to find the right part's, the right combination, the right turbo. It's even more of a balancing act. A few degree's out on the timing & you've got some rod's & piston's that are nothing more than paper weight's.

It's just as involving, but when someone else has done it, it does make it easy to copy.

[GoLfMan]

i agree a highly strung NA around the street wouldnt be fun to drive in heavy traffic, thats why V8's are so much better to tune for power, minimal money on mods and you get massive gains and its still easy to live with!!

[Valver.]

Valvers engine that has been built specifically for big power turbo output

Just for the record, the ABF block in the white car is pretty much standard. It just has fresh parts, ARP bolts and a decompression plate.

TBH, I've built it to see how much boost it'll take before blowing up. It's actually RPMs that kill a 16v anyway; they seem to take a lot of boost for a long time if they're kept around a 7k rev limit :)

This is one of the other reasons it costs so much to build a nice ITB'd engine: the cams you need to actually use all that extra intake capacity demand so many revs, and you can't get much more than 7.5k out of a stock bottom end, and a bit over 8k revs from hydraulic lifters.

You also need to rev high enough to actually get a decent power band. If you didn't rev, you'd want a 7spd 'box!

There are huge improvements to made outside of the engine anyway. Putting a 3.94:1 final drive in a 16v 020 (and most 02As) feels like you've got another 30hp and your flywheel has shed half its weight. You can't really do this in a big boost engine as the torque will light up all the gears - you have to keep the longer ratios so it comes on a bit more lazily (unless have AWD of course). Being able to build a gearbox with taller 1st and 2nd, and then tighter stacked 3, 4, 5, 6 would be the best of both worlds, but that would be $15,000.

As Preen says earlier, getting near 200hp is great fun a Mk1 anyway :) I've only turbo'd mine out of curiousity - if the truth be known, it'll be a slower car in a lot of areas due to the lower compression, gearing, and the lag!

[Valver.]

P.S. A lot of the US and UK cars that apparently knock on 200hp with an $800 head job and KR cams need to remember that the early 16v power-up from Oettinger etc (with warm cams, great heads, and very nice exhausts) were only rated at around 175-180hp! The 190hp versions had 276 cams. I'd be more inclined to believe an engine dyno worth a few hundred grand than some bloke in a shed apparently getting a 40hp+ increase from a very poorely designed engine (!).

[GoLfMan]

bugger i was wrong again! ahh well *crawls back inside hole*

your car will be an absolute weapon on boost, but dont get caught in the wrong gear and off boost! :o should be sweet to see how it goes with the turbo set up

[velly_16v_cab]

P.S. A lot of the US and UK cars that apparently knock on 200hp with an $800 head job and KR cams need to remember that the early 16v power-up from Oettinger etc (with warm cams, great heads, and very nice exhausts) were only rated at around 175-180hp! The 190hp versions had 276 cams. I'd be more inclined to believe an engine dyno worth a few hundred grand than some bloke in a shed apparently getting a 40hp+ increase from a very poorely designed engine (!).

coming from the uk and being a 16v lover i can say yes there is a load of 16v's pushing out 180 BHP @ fly.
i have a mate who has built 2 2.0 16v's which both run over 185bhp and is also building a 2.1 (another mates 2.1 on twin 48's -pushed out over 200bhp)

it can be done...ive seen it:cool:

[Preen59]

Just for the record, the ABF block in the white car is pretty much standard. It just has fresh parts, ARP bolts and a decompression plate.

TBH, I've built it to see how much boost it'll take before blowing up. It's actually RPMs that kill a 16v anyway; they seem to take a lot of boost for a long time if they're kept around a 7k rev limit :)

This is one of the other reasons it costs so much to build a nice ITB'd engine: the cams you need to actually use all that extra intake capacity demand so many revs, and you can't get much more than 7.5k out of a stock bottom end, and a bit over 8k revs from hydraulic lifters.

You also need to rev high enough to actually get a decent power band. If you didn't rev, you'd want a 7spd 'box!

There are huge improvements to made outside of the engine anyway. Putting a 3.94:1 final drive in a 16v 020 (and most 02As) feels like you've got another 30hp and your flywheel has shed half its weight. You can't really do this in a big boost engine as the torque will light up all the gears - you have to keep the longer ratios so it comes on a bit more lazily (unless have AWD of course). Being able to build a gearbox with taller 1st and 2nd, and then tighter stacked 3, 4, 5, 6 would be the best of both worlds, but that would be $15,000.

As Preen says earlier, getting near 200hp is great fun a Mk1 anyway :) I've only turbo'd mine out of curiousity - if the truth be known, it'll be a slower car in a lot of areas due to the lower compression, gearing, and the lag!

I agree with all that. The early oettinger engines were a 1.6 though. Well i'm pretty sure they were.

Techtonics Tuning told me that standard 16v internals (same rods as the 1.6, 1.7, 1.8 and early 2.0) will handle 25 PSI or around 8000rpm respectively. The thing to remember with VW engines is that the RPM is deceiving. They have a MUCH longer stroke than say a honda or toyota, and are actually over-stroked really.

Engines start running into problems with pistons generally around a piston velocity of 25m/s (metres a second), from what i've hear'd off most engine builders, above that the thermal load on the side of the piston becomes too great, with the addition of the increasing reciprocating force and BANG.

So at 8000rpm a VW 86mm stroke 1.8 has a piston velocity of 22.9m/s, very high for standard cast pistons. Although i was told by TT 8500 would be ok on standard internals.

A Honda 1.8 VTEC 77mm stroke at 8000 rpm has a piston velocity of only 20.5 m/s. Fairly mild, so you could rev it to say 9500 before you would run into problems.

[Preen59]

I suppose i should tell you how to work out piston velocity.. It's pretty simple.

Piston velocity is simply the speed that the piston is traveling at, at a given RPM.

We'll go with nice round numbers here to keep it simple.

Smokin Joe's 58 valve 4 cylinder has a stroke of 80.0mm and he sets his limiter at 9000 RPM.

RPM is revolutions per minute and we want a value in seconds, so:
9000/60=150.

Remember that in one complete revolution the piston goes from Top Dead Centre to Bottom Dead Centre, and then back to the top, so:
2x80.0=160.

Now, every one second at 9000rpm the engine rotates 150 times, so:
150x160=24000.

24000 is a figure in millimetres and we want metres, so:
24000/1000=24.

This gives us a piston velocity of 24m/s (metres per second) at 9000rpm.

I hope i've explained that clearly, let me know if i haven't.

[aprr32]

If you want honest 200+hp,reliable and driveable just put a 20v turbo in.No opening the engine to do mods,just wind up the wind and enjoy 280 hp at the fly with driveability that my even grandmother can enjoy.I've been down the highly tuned, bad mannered and short lived na's road years ago and while it's fun for a while, driveability is everything these days.

[GoLfMan]

I suppose i should tell you how to work out piston velocity.. It's pretty simple.

Piston velocity is simply the speed that the piston is traveling at, at a given RPM.

We'll go with nice round numbers here to keep it simple.

Smokin Joe's 58 valve 4 cylinder has a stroke of 80.0mm and he sets his limiter at 9000 RPM.

RPM is revolutions per minute and we want a value in seconds, so:
9000/60=150.

Remember that in one complete revolution the piston goes from Top Dead Centre to Bottom Dead Centre, and then back to the top, so:
2x80.0=160.

Now, every one second at 9000rpm the engine rotates 150 times, so:
150x160=24000.

24000 is a figure in millimetres and we want metres, so:
24000/1000=24.

This gives us a piston velocity of 24m/s (metres per second) at 9000rpm.

I hope i've explained that clearly, let me know if i haven't.

nice and easy! thanks mate :D im going to find that useful

[Preen59]

Righteo BDA fans, cop this! This is a post on a US forum from a tuner in greece. He's building a VW 2.1 16v to produce atleast 1000hp.

Here's the thread: http://www.vwfixx.com/forums/index.php?showtopic=25719

Ok lets talk about engines. Lets compare some of the best engines with the vw 16v engine.

First when i built an engine i determine the purpose of the engine and the rpm bandwith that i will need the power. How many horsepower i will need and the engine time limit.(reliability).

Reliability and power is something completly diferent.

2 things makes an engine broke : piston velocity and piston aceleration.
When an engine have long stroke the piston velocity goes higher. Typicaly 25m/sec its the limit of a normal engine. The abrasion of the piston inside the engine is very important. So a vw 2ltr engine with 92,8 stroke have 25,1m/s at 8100rpm. If we need to work this engine to higher rpms we must reduce the stroke, for example: from 92,8 to 85 (1817cm3) at 8100rpm we will have 23m/s so we can go to 9000rpm that we will have 25,5 m/s piston velocity. Some guys think that displasment is better than higher rpms. Thats stupid. I prefer an 1.670cc engine that revs 12000rpm thank a 3ltr engine that works 7500rpms. This balance is absolutely calculatable. All the mater is the actual flow of eatch engine lbs/min.Lets see an example:
3ltr engine with 8,5 comp.ratio and 7500rpm limit with volumetric efficiency 82% will gave us 62lbs/min. A 1,7ltr engine with 11 comp.ratio and 12000rpm limit with volumetric efficiency 82% will gave us 70lbs/min. The things are clear.
The other thing is the piston aceleration. Its very important the type lenght of rod / stroke ratio. The vw 2ltr engine have 159/92,8 = 1,713
1,6 - 1,7 is bad engine with rpm limit until 7000rpm max.
1,7 - 1,8 is good engine that can revs 9000rpm.
1,8 - 2,0 is very good engine that can revs 12000rpms.
So vw engine with 1,713 have 30000m/sec2 acceleration piston velocity and piston position from TDC 50000m/sec2 acceleration. When this prices reduces the best lenght to stroke ratio we have. My engine now have 2.105 length to stroke ratio and gives me the benefit to rev it until 12700rpm with no problem. For example a cosworth engine that have 90,8mm piston 76mm stroke and 130mm rod its better engine from stock 2ltr vw because have at 10000rpm 25m/sec 1,710stroke ratio. But thats only the design of the engine. Design of the engine cant give us power but can alow us to rev the engine higher. Cylinder head makes the power. Some theories tells that an cylinder head with bigger valves is better. Thats almost inacurate.
Typical its true but in real fact is mistake.Lets see the theory.
Vw 1.8ltr kr head have 117cfm inlet and 91,2cfm exsaust.
Cosworth have 122cfm inlet and 95,9cfm axsaust.
Theory tell us:
CFM x No. of Cylinders x 0.43 = BHP
Vw 117cfm x 4 x 0.43 = 201.24 bhp.
Cosworth 122cfm x 4 x 0.43 = 209.84 bhp.
Cosworth intake valve is 35mm and vw 32mm.
Typicaly the cosworth head its better BUT lets see it in action:
All the matter of power is how much mixture can pass at the same period of time.
Lets compare the 2 engines with same parts exaclty:
Vw 32mm intake valve 8000rpm limit and 10mm valve lift.
Cosworth 35mm intake valve 8000rpm limit and 10mm valve lift.
Cosworth 131,14 m/s flow mixture.
Vw 140.86 m/s flow mixture.
Thats the real benefit of the vw engine that noone knows.
The cosworth have 1005.16 mm3 valve open, vw have 942.33 mm3 but thats nothing to do with power / flow mixture per sec.
These years i am searching all the kind of engines i ve spent many many hours compare eatch other. Cosworth, Opel Vauxhall XE 16v, 3Sgte st205, Mitsubishi evo. Cosworth is the best of all the above and its more easy to tune.A good engine is more cheap to make it better but a normal engine is most expensive and dificult to make it better.I ve spent thousants of $ and private time to compare all the engines and to make the normal vw engine propably the best of all. I can write for hours but i have limited time.



Spyros

[Jarred]

yea, my head just exploded.

[twin eng, twin turbs]

Spyros is the man! reading all the posts he has in that thread is awesome. When i built the original atmo 1.9l 8v in Preens mk1 it had 42mm inlet 35mm exhaust valves, schrick 272 cam, porting and polishing, 10.5:1 compression, fully balanced, lightened flywheel, 1 5/8" 4 into 1 tuned lenght extractors 2 1/2" system and running on twin down draught 40mm webbers etc. The list goes on but my point is it was essentially totally worked for a nicely drivable street car but only made a maximum 170bhp. It is not easy to get big numbers from an atmo engine and keep it driveable or do it cheaply. I like webbers and ITB's but for out right power forced induction is the way, keep the revs down to below 8000rpm max and vw's respond very well to psi..

[Sharkie]

I used to run 2 engines on my Mk1. Both 1800 16v, the one with the turbo making close to 400bhp @fly (290kw) and a NA with 2x 45mm Weber SDs making 112kwatw (150bhp) or 130kwatf (175bhp). Enlarged (modified) throttle bodies in both cases.

You have to remember that this was at altitude (1800m above sea level) and included a loss of 18% (NA) and 11% (turbo) from sealevel figures.

The NA was a hoot to drive and used when the turbo motor was undergoing work...... we got swap over down to a couple of hours eventually as the turbo motor needed some work quite frequently.....:(

Watch the cam chain tensioner pully bolt as we snapped it twice (I still don't know how....) and had to redo the head once and replace it once.....

However notwithstanding a bit of lag down low, nothing touched it when it was on boost. Absolutely crazy and the most fun you can have with your pants on..... ;)

[velly_16v_cab]

If you want honest 200+hp,reliable and driveable just put a 20v turbo in.No opening the engine to do mods,just wind up the wind and enjoy 280 hp at the fly with driveability that my even grandmother can enjoy.I've been down the highly tuned, bad mannered and short lived na's road years ago and while it's fun for a while, driveability is everything these days.

if your talking mk2 or 3 then a VR6 will give you 200bhp all day long :)

but yes, 20v T is the simple all rounder :) :) :)

[Valver.]

I agree with all that. The early oettinger engines were a 1.6 though. Well i'm pretty sure they were.




You're thinking of the 16s. Oettinger also provided aftermarket tuning packages for all 16vs :) Though, they were hugely expensive!

[Valver.]

but yes, 20v T is the simple all rounder

My washing machine sounds nicer than a 20v :D

[Preen59]

My washing machine sounds nicer than a 20v :D

hahahaha! Amen to that! Talk about done to death!

And the vr6 may give you 200 hp, but the engine weight makes the front of the car very lazy (I don't care what suspension you have, it won't point and hold on the nose like a mk2 or 3 with a 4 cyl in it). Sound good though.

[velly_16v_cab]

My washing machine sounds nicer than a 20v :D


i cant really argue with that j:

a 16v on full chat still gives me wood :D