Engines under forced induction

[Shteifen]

Ive been getting alot of mixed responses when i ask different people about this. People being teachers at tafe, and other qualified technicians.

Is an engine under forced induction going to last very long? and how long?

i would assume its not going to last as long, just based on physics.

i suppose it also depends on many thing like what oil you use, how much boost its running, whether its turbo or supercharged, what parts it was made with and how long ago it was made with them ( by parts i mean pistons, rings, rods, bearings, valves etc.)

i ask this because its going to affect how i build my engine. or rebuild i should say. whether i do it for FI with relatively stock, or maybe a little lower compression, or NA with higher compression, either way i dont see why it shouldnt be a 3.0 litre.

from what i gather NA will last longer and i suppose its going to have a higher resale value (MUCH later down the track) and FI might die a bit quicker and anyone who knows anything will know its been thrashed.

by the way, if i do chose FI itll be a super charger as rediculous power on a front wheel drive is pretty useless.

what are anyones opinions on the longevity of FI verses NA engines?

-steve

[Bubu]

i suppose it also depends on many thing like what oil you use, how much boost its running, whether its turbo or supercharged, what parts it was made with and how long ago it was made with them ( by parts i mean pistons, rings, rods, bearings, valves etc.)


You said it!

It also depends how well you maintain it and how hard you drive it.

When people tell you turbo engines dont last, just think of all the trucks out there that have done 1 million kms, and those trucks run high boost too. Its probably not the best comparison, seeing that trucks run on diesel and are built to go the distance, but it does show that a FI engine can go the distance.

Also another thing to keep in mind, is if the set up and tune is done right you dont have to rev a FI engine really high to get good power, unlike a N/A engine. Revving your engine high will cause extra wear on the engine over time.

[Mrk_Mickey]

This is just my opinion..

To be honest, I think that if you maintain the engine well and build it PROPERLY for the outcome that you want, you will have an engine that, if continued to be taken care of, will outlast most if not all the other engines of the same type.

[Jarred]

Nelson racing engines make streetable big block TT engines that put out with in the region of 1500-2000HP. now they do that with lots of boost and lots of cubes, but they're still turn key reliable.

how? all got to do with building the right set up with the right bits, and maintaining it properly.

[KI11Z]

I believe that a tuned n/a engine will not last as long as a tuned fi engine, n/a would be under a lot more stress with its high compression and high revs. if you want reliable cheap power, go a low boost sc or turbs setup. my2c

[Spyda]

I believe that a tuned n/a engine will not last as long as a tuned fi engine, n/a would be under a lot more stress with its high compression and high revs. if you want reliable cheap power, go a low boost sc or turbs setup. my2c

I agree. A FI engine on low boost should out last a NA engine making the same power. But i guess it all depends on the motor.

[Mrk_Mickey]

i guess it all depends on the motor.

Not to mention the parts used too. You know how it goes... ''you get what you pay for'' yada yada, i would just say that going skimp on something internal would be a bad idea, unless its been proven that's it's still good.

[KI11Z]

yes, without a doubt, remember, THE MOST EXPENSIVE WAY IS THE CHEAPEST WAY! :biggrin:

[mr gee]

Would be interesting to hear what those TAFE teachers and technicians have to say.

If both NA and FI engines are designed from the onset to do as advertised, they will last as long as their designers deemed them to last.

Obviously, speccing the right materials, bearing loads, lubrications etc as you said will go meet those ends.

If you treat an NA engine to an aftermarket turbo, then you will be imposing additional stresses not intended of it by the designer. However, engines are built with a certain amount of tolerance and therefore if this is not exceeded, there's no reason that engine will not last. There is also something in that an NA engine needs loads of revs to get power whereas a FI engine revs less and produces more torque imposing less 'G' loads on the con rods as a result.

I've played with some aftermarket turbos as well as boosting turbo cars usually by only about 50% and had no reliability issues with the engines though clutches are another matter. lol

[DubSteve]

There are guys with chargers on vortex that have lasted them with 100 000 miles, so I think your ok with it.

[dado]

high revs kills the FI engine not high commpresion,so it is right balance really and properly run FI should outlast NA engine in my opinion.

[Shteifen]

this is good discussion, i like it!

i would think with an FI engine with a turbo would require a little more maintenance than a supercharged one, just because of the heat generated by the turbo getting so hot would make the oil turn acidic quicker causing the engine to wear. so i suppose a turbo engine would require oil changes more frequently, would that be right?
supercharger wouldnt get as hot i'd imagine.

i think i heard somewhere when i was younger that it puts components under less stress to make power at higher RPMs. like for example a stock 1.8t motor, makes its highest torque at around 1750 rpm. now wouldnt having the piston forced down with an explosion at such low rpm make give more stress to bearings in the crank and rods and such for a longer time, than making the same power higher up, at say 4000rpm? maybe thats not a good comparison.
i suppose making the power higher up might be putting less stress on the bottom end from torque, but more stress on other components, like rings, because they are doing that same movement with a force for a shorter period of time be much more often...


and just to clarify either NA or FI, i wouldnt be looking for massive power, just a fair bit more than i have now and a nice sound.
i wouldnt be skimping on any parts either, pretty much everything would be replaced, bringing km's back to zero, on the engine and maybe the gear box too.
if FI i was thinking a supercharger at around 6-8 pounds would do it, with some cams, in a three litre would do it nicely.
if NA i was thinking, still the three litre, cams, good p&p job, and maybe 10.5-11:1 compression, so not crazy compression but a bit of a bump.
either way i go, FI is going to be more expensive because i'd have to fork out for the parts of rebuild, and on top of that the FI parts.

-steve

[Bug_racer]

I'll make this a simple post as I could be here all day :

Turbo it . low boost with a fresh engine . If your worried about longevity and engine bay temps lower compression ratio and add a thermostatically controlled oil cooler . A turbo running low boost will have the most volumetric efficiency vs cost of any engine in the long term .

Keeping it naturally aspirated to gain more power your going to need to rev it harder , boring and stroking does little on a VR6 , its the head that cant flow . Once youve opened to the head up and it revs , you'll find your gonna need to cool the engine down cause of the extra heat generated & your gonna need to run high octane fuel all the time . You'll find you'll be getting more oil / coolant leaks as well , as well as the pulleys / p/s pump , water pump etc needing to be changed more often .

Supercharging is inefficient . To make the power you have to use the power , and on a small engine like the VR6 it robs it off too much in order to work efficiently . superchargers work better with larger displacement .

[Jarred]

I'll make this a simple post as I could be here all day :

Turbo it . low boost with a fresh engine . If your worried about longevity and engine bay temps lower compression ratio and add a thermostatically controlled oil cooler . A turbo running low boost will have the most volumetric efficiency vs cost of any engine in the long term .

Keeping it naturally aspirated to gain more power your going to need to rev it harder , boring and stroking does little on a VR6 , its the head that cant flow . Once youve opened to the head up and it revs , you'll find your gonna need to cool the engine down cause of the extra heat generated & your gonna need to run high octane fuel all the time . You'll find you'll be getting more oil / coolant leaks as well , as well as the pulleys / p/s pump , water pump etc needing to be changed more often .

Supercharging is inefficient . To make the power you have to use the power , and on a small engine like the VR6 it robs it off too much in order to work efficiently . superchargers work better with larger displacement .



:bowdown::bowdown::bowdown:

/end thread imo

[gareth_oau]

more and more manufacturers are running forced induction these days, and they cant afford to do this unless it comes with a reasonable level of reliability or theyd bankrupt themselves with warranty repairs.

you can also expect that they will build a decent safe working margin into them so if you choose to go higher that standard then it wouldnt be overly risky.

I worked and turboed a 2L ford engine many years ago, and was getting over 250KW from an engine originally built for 70KW. Was superb fun until one of the conrods headed west instead of north/south. but in this instance i well and truly overdid it, and I suspect a lot of bad stories are from people who have overdone it, or not done it properly

[Shteifen]

good points.

i agree, new engine are made very well, and deal well with forced induction probably because of the massive budgets these companies have to invest in research and development of components to that last.

in an older engine type, like a VR6, to make it ready for forced induction would a simple rebuild be enough? would all the bearings, pistons, rods, valves, guides and such of an engine rebuilt with stock components be enough to deal with different levels of boost?
i mean that engine was never meant to be boosted, so is a refresher all it needs to be suited for it? or are there specialised bearings parts that should be used for a forced induction engine compared to an NA motor?

-steve

[gareth_oau]

i would imagine any dealing directly with the power, ie valve sealing, pistons, rods, BE bearings etc would need to be redone.

clutch as well.

and while its in bits, get your head port/polished - a lot of gains can be realised from removing manufacturers tolerances

[Shteifen]

yeah, id be gettin everythin replaced. probably go for makin it a 3 litre as well :biggrin:

get head fully rebuilt along with the p&p. probably wont bother with bigger valves or anythin though.
bottom end rebuild as well, all crank and rod bearings and whatnot.

ah well, theres so much i could end up doin, just a matter of whether i can justify the work/money/time.

-steve

[GoLfMan]

Listen to Bug_Racer (Seb) he has ALOT of experience in hotting up the VR6! He's building a VR6t drag car at the moment I think? (correct me if I'm wrong Seb)

as he said, I personally wouldn't supercharge it, you wont gain enough to make it worthwhile and a low boost turbo set up will yeild more power

[gareth_oau]

if youre already getting the head rebuilt, then why not use bigger valves? I cant imagine the incremental cost being too prohibitive and if youre going to be using/producing a lot more gases, you'd want to get them in and out of the engine a lot quicker?

[Shteifen]

Thats true i suppose. haha might as well eh?

for that sort of work would be best to send the block and head to someone who has experience in these engines or will anyone do? I'd probably rather send it to someone who has had some experience, though i don't know if there would be many, so they'd be expensive i imagine.

the main reason i preferred supercharging over turbo is because all the videos ive seen, the turbo vr's never quite sound like a vr, where as the super charged ones do. the turbo ones sound almost muffled and pretty much the reason why i got this car was cos of the sound. and a little more power obviously.

-steve

[Jarred]

i'd go a blower if i was after big HP numbers, but seeing as though you don't seem to be after out right HP, whack a blower on!

i'd don't think you'll need to go overboard with the head work, but just cleaning up the factory tolerances & port matching is v.good.

any head guy worth his weight should be able to do it.

[Shteifen]

Exactly, i wouldnt be after massive numbers, cos i dont want to buy a new gear box every few months. it'd be my daily driver so i wouldnt want it to be undrivable. i'd be building it to last and the power delivery to be comfortable.
i dont see the point of getting to 2.9k rpm and having no traction in 1st, 2nd and 3rd...

i read somewhere that you get a choice of two of the following three :power, reliability and cheapness of build.
i choose the first two, rather than stay stock and buy another car in a couple years :biggrin:

did you mean you'd go a blower ( to me ablower is supercharger) if you werent looking for massive power? or by blower did you mean turbo?

-steve

[gareth_oau]

and the whine of a supercharger (blower) is sooo nice!! LOL

check out this whine!!

http://www.youtube.com/watch?v=FBkX8GS5FoY

[Shteifen]

thats EXACTLY what i mean too!
haha

-steve

[Jarred]

blower as in supercharger. huffer is a turbo.

that's what i call em any ways.

[Shteifen]

ah k.

yeah the sound is the reason i was thinkin blower, both because it keeps the vr sound and also cos of this whine of the charger. but then as previously stated, it uses power to make it which has always bothered me :frown:

turbo would be wicked though. i suppose a low boost setup sounds ok with a fully worked head and block. shouldnt get rid of the sound too much at low boost. then ofcourse there is the spooling noise which is always good. such hard decisions

-steve

[mk1turbo79]

If you go with a supercharger, would you use a vortech v9 or v2. If so they do not take huge HP to turn unlike a roots type charger. I read somewhere that it was only 5-10HP. The other benefit of a centrifical charger is you don't really have to build a super strong gearbox, because there is no huge spike in power or torque. The give a linear curve.

On the other hand turbo is better in my opinion.

[AusScare]

Is a supercharged setup cheaper than turbo for just the basic setup?

What dollar amounts are we talking for each, to make it stable.

[peedman]

Is a supercharged setup cheaper than turbo for just the basic setup?

What dollar amounts are we talking for each, to make it stable.

Well the vf engineering supercharger kit is $3500USD and the Kinetic turbo kit is $3150USD so price range is very similar. The difference is that vf make a kit specific for the non-us spec cars whereas the kinetic kit doesnt and that brings into question whether the software will work and whether the turbo manifold/down pipe fits (lhd vs rhd). In the end these kits only run 6psi and power would be pretty similar. Reliability shouldnt be of concern if u dont drive like a tard and do regular services. Dont forget this is without shipping so to get the kit sent here u would be wont be looking at getting much change from $5000AUD.

[KI11Z]

. . . get head fully rebuilt along with the p&p. probably wont bother with bigger valves or anythin though. . . .-steve

I'm having my head worked on at the moment (n/a styles) by a very reputable company who builds all sorts of engine for customers here and overseas; I raised the question with him with regards to people "losing" power after head work and he replied that there is no point in just doing a port and polish on the vr6 head as the size of the valves are well matched to the port sizing, just increasing the port size will only have you going backwards, also if you don't raise the rev limit after a head job (:p) you'll go backwards again. If you don't want bigger valves just have someone give it a lil clean up.

I also doubt it would be worth your coin getting decent head work done if your going fi, its not cheap and the gains would probably be minimal since your forcing air in there anyways . . .


. . . . either way i go, FI is going to be more expensive because i'd have to fork out for the parts of rebuild, and on top of that the FI parts.

-steve

if you don't get head work and run stock pistons with a head spacer i don't think fi would be more? n/a is a far bigger exercise, to do it right, lightweight components like rods, retainers, lifters.. high compression pistons, stand alone computer, balancing components to cope better at high rpm, proper head work incl. cams, anything else? I doubt you need to do any of that to go fi, bolt on 5k kit and drive away . . .

[Shteifen]

hmm... yeah i'd rather not go over kill on heaps of work. im really lookin for an engineand head rebuild/refresh and thought while im in there i might as well make everything a little better, stronger really. a bit of a head clean up sounds good, cos like you said, if FI is used it dont have to flow quite as well as it would if it was NA.

i know this has been talked about alot before, but would it be cheaper to buy a complete kit from the states where you'd just buy it and chuck it on? or to go to a performance company here and get them to put together a kit, or put one together yourself?
ebay kits are ofcourse out of the question!

-steve

[Shteifen]

are thee any complications with reusing the old pistons in a rebuild? especially if honing is done? would there be tolerance issues? like too much gap?

-steve

[Jarred]

I would look at getting a kit personally, perhaps you can organise to only get the parts of the kit that you need, rather than getting US spec stuff, like DP's and software you don't need.

Kit would probably be cheaper, and that way parts are (or atleast should be) matched.

[Shteifen]

tis a good point.
US kits dont fit ours cos the brake master cylinder components and steering junk are all in the place where the turbo sits right? and with supercharger, the brake M/C and reserviour sit where the intake pipe'll go?

to do with management, would a simple FI chip written for my ecu do the job or am i gonna have to go for standalone?
-steve

[Jarred]

if you keep it below like 7psi, the stock ecu can handle it, above that the stock ecu fries aparently..?! This is only what i've heard mentioned a couple times.

I believe Seb, (bug_racer) was working on something though.

[Shteifen]

ive been wondering how much a stock ecu can take! my brother said his bmw e30 is supposed to be able to take about 7 pounds too, and he asked me about mine and i said i assumed ver little, that id never heard it mentioned that it could take it at all.

i suppose to account for atmospheric pressure differences they'd have to build it with that in mind, but atmospheric pressure doesnt differ to the extent of boostin, but still, tolerances to an extent.

7 pounds you've heard? with the lowest boost kit runnin 6 pounds, thats a bit close for me to be comfortable with but thats still good to know :)
-Steve

[peedman]

you'd be stupid to spend 3k+ money into a turbo kit and not get the ecu reprogrammed to run the tune...

[Shteifen]

absolutely! theres no way id do that, thats what guys at my tafe do!
thats why i was askin about it, i wanna figure out which route is most cost effective

-steve

[mk1turbo79]

I don't now where people are gettin the 7psi max on stock ecu. VF stage 3 is running 10psi on stock ecu with a giac chip.

As for the S/c kits fitting in a RHD, i know the VF stage 2 fits no problem with good access to the brake reservoir.

[peedman]

I don't now where people are gettin the 7psi max on stock ecu. VF stage 3 is running 10psi on stock ecu with a giac chip.

As for the S/c kits fitting in a RHD, i know the VF stage 2 fits no problem with good access to the brake reservoir.

I think they are talking about running a turbo without touching the ecu i.e. no chip no nothing. If i had the dosh i would rock a kinetic stage 3 turbo kit but the price is.......wait for it........$4250USD :eek:

[Bug_racer]

Kinetic wont deal direct with people here cause our ecu's are different and they will not deal with people here on an individual basis . I'll have an Australian spec ecu available shortly . The stage 1 kits here will be approx $4500 with the current exchange rate .

[Pullstarter]

That's a good proce Seb!! Are you using the Kinetic kit on your build?

[VR6man]

As an owner of a turbo car (not the VR6 lol) you need to consider how you will use the car.
As a daily driver there will be a limit on how much power you can actually put to the ground.
Are you willing to upgrade your brakes and suspension, put in an LSD.
I would rebuid your motor especially if it has high kms.
Add low comp pistons, new rings and bearings and general machining.
Clean up , reco and resurface the head, reseat the valves and better valve springs.
Custom manifold, GT3082R turbo (Ball bearing turbo) with internal wastegate, braided Oil & Water lines, etc etc etc etc .
And a custom tune.
If you want some contacts just PM me.

[Shteifen]

oh i talked to VF about their supercharger kit for mk3 vr's and they dont make them for it anymore. and dont have any plans on making them again :eek:

kinetic didnt seem to have a problem with sending one over the second i emailed them though? Mark Ashcroft was the guy at kinetic i was talkin to. regarding ECU's he said he'd talk to the C2 about it but didnt get back to me about it.

this was back in march for both companies that i talked to

4500 sound reasonable Seb, thats for the turbo kit yeah?

GT3082R is pretty big isnt it? i mean its not massive but its on the larger side of say the T3/T4 that comes with a kinetic kit isnt it? (i dont knwo much about different models or specs of turbos and compressors and whatnot btw)

-steve

[Shteifen]

ya suspension and all bushes have been upgraded.
got the 97 vr brakes, the 288m ones so they should do for now at least, can always upgrade later if i find they arent cutting it. gear box work would be on the cards too along with the rebuild.

-steve

[VR6man]

GT3082R is pretty big isnt it? i mean its not massive but its on the larger side of say the T3/T4 that comes with a kinetic kit isnt it? (i dont knwo much about different models or specs of turbos and compressors and whatnot btw)

-steve

Perfect size for a 6 cylinder around 3 litres, will boost quickly with its smaller turbine wheel and won't require a huge intercooler.
T3/T4 is a bush bearing and will generate way too much heat and is only oil cooled where the GT3082R is water and oil cooled required very little cool down time.


got the 97 vr brakes, the 288m ones so they should do for now at least, -steve

great, I'm using DBA slotted rotors with mintex pads and its made a huge difference

[Jarred]

Have a look on vortex, but i'm pretty sure GT30 is kinda the smaller side/ entry level size turbo on turbo'd vr's.

[Shteifen]

ya i thought the samllest sort of turbo i'd seen used on vr's on vortex was about a gt28. so i suppose a gt30 would be decent.
what rpm would something that size look like starting to spool and what rpm for full boost?
one thing i cant stand seeing or feeling for that matter, is puttin your foot in and gettin small power, then all of a sudden you can do nothing but wheel spin. thats useless. good to brag about maybe at dyno days, but useless for a daily.
you see it on videos on youtube all the time, they get to like ~3k rpm and hit full boost and wheel spin through 1st, 2nd and 3rd. useless. to me anyway.

the brakes on my vr feel SO much better than those of the 2.0 mk3 that i had before hand. massive improvement. may upgrade pads and rotors if i need to but these stop me ok at the moment :)

-steve

[mk1turbo79]

A gt3082R with a 1.06 exhaust housing on a 2.9L was starting at 2.8k an full boost by 4k. With a .82 exhaust housing it is about 400rpm earlier. The other option is a 0.63 exhaust but is getting a bit small and may choke up at high rpm.

[DubSteve]

Kinetic wont deal direct with people here cause our ecu's are different and they will not deal with people here on an individual basis . I'll have an Australian spec ecu available shortly . The stage 1 kits here will be approx $4500 with the current exchange rate .

Can you please elaborate on this?

What kind of turbo kit is it and what does it consist of?

[POLARBEAR666]

One point to consider is that turbo cars generally produce far more torque down low than N/A cars of similar capacity.

Therefore they don't have to rev as much and this places a lot less stress on the engine components in the heads. Revving high wears your heads out much faster than 100,000 of low rev action. The springs will be thrashed after 100,000 if they are revving higher all the time to get moving.

Most turbo cars also have a stronger piston/rod combination and usually better head studs as well. This means they won't be under much stress.

The question of longevity for turbo cars is tuning and boost. At a certain ratio of boost turbo engines longevity goes down a lot. Eg twice factory amount on subaru's and you have to start rebuilding the motor for head gaskets every 30k as a precaution so they don't pop.

A turbo engine is like an 80kg guy who does weights lifting 100kg vs an 80kg guy who does no exercise lifting 50kg. The guy doing 100kg will probably still do more exercise than the unfit guy (N/A). Like the turbo diesel toyota hilux's that get more than 500,000k's on their first motor before a rebuild. I know this as I used to work for toyota australia.

[Shteifen]

Seems to make sense to me.

How strong does a piston rod combo really need to be to deal with low to medium levels of boost? thoughts?
on a vr6, on vortex obviously alot of people are running vr6t's and sc's on stock blocks, and they seem to go just fine.
obviously thats not built for forced induction, but does an engine really need forged everything to be built for forced induction?

-steve

[jayjay]

forged internal components will be under the same stress as stock interals however due to different piston design - ie surface area shape and material, they will have a higher maximum allowable stress, and hopefully will not succumb to yielding from heat and the higher force generated from boost.
:)

[Shteifen]

so for around stage 2ish, like around maybe 250-280whp (no i cant be bothered workin out what that'd be in kW), would forged rods and pistons be justified? or a little over the top for a fast street car?

-steve

[Mrk_Mickey]

I'm not actually sure about this so it'd be nice to get an answer...

I was always under the impression that forged internals were for cars making respectable power. That is, cars that aren't just a stage 1 bolt on turbo kit and exhaust. I'm thinking more a stage 2 with decent mods or a basic stage 3...

can someone confirm? :)

[Shteifen]

thats was i was thinkin too man :)
dont see the point in gettin forged super strong internals for making stupid power in a front wheel drive car anyway. 4motion on the other hand, hell yeah, go all out and make as much power as you want!
-steve

[DubSteve]

so for around stage 2ish, like around maybe 250-280whp (no i cant be bothered workin out what that'd be in kW), would forged rods and pistons be justified? or a little over the top for a fast street car?

-steve

What for I'm looking at a kinetics kit at the moment that is with a T3/T4 turbo looking at around 300whp without a front mount.

And all that is, is the bolt on kit.

[Jarred]

heaps of guys on vortex run big numbers with standard bottom ends.

I've heard things like 400HP, but not 100% sure. .. Anyone have some links??s

[Shteifen]

ya they run real big numbers over there. i was just wonderin if there is any proven way to make your bottom end stronger other than doing a rebuild, cos i already plan on that.

are there any sorts of bearings that would be more suited for forced induction?
any sorts of oils?
valves? (other than just big ones, i mean the metals they are made out of) :biggrin:
is it a bad idea to reuse on rods? i know they wouldnt be as strong as forged ones (actually i cant remember which parts of a vr bottom end is already forged, though im pretty sure something down there is. maybe the crank or something, i forget)

-steve