PDA

View Full Version : Turbo high flowing!!



twin eng, twin turbs
05-09-2008, 10:22 PM
With the desire for a bit more power i decided to upgrade the current turbo on my mk2 gti but with space a very limiting factor and seeing as i had allready made the manifold, down pipe, induction pipe, intercooler pipe work, oil lines etc etc to suit my current turbo i looked into the different options for high flowing the IHI VF22 turbo i had installed.

This model turbo is the biggest subaru used on the wrx sti models, providing great top end with the sacrifice of a little bottom end drivabilty or lag! Not that i experienced any lag with it as my exhaust manifold is short with 4 into 1pipe work merging together at the turbine housing. It was making boost under 2000rpm in all gears. This turbo flows 325hp with peak efficency at 18psi.

A lot of aftermarket companies supply upgrades for the wrx, sti, forestor gt that this turbo can bolt straight onto but at a big price! So i decided to upgrade the internals using the centre core from a garrett GT 25/40 turbo i had saved for the twin eng mk1 and machining it to suit the IHI exhaust and compressor housings. The garrett GT 25/40 is a awesome ball bearing turbo with great drivability flowing 440hp with a 0.64 air ratio exhaust housing and 480hp with the 0.86 air ratio exhaust housing. The vf22 exhaust housing flows almost as well as the garretts 0.86 unmodified but i have ported and polished it to get the most out of it.

Heres a pic of the vf22 after removing it from the engine. I have modified it a lot from standard.

twin eng, twin turbs
05-09-2008, 10:39 PM
You can see the 3" inlet an 2" outlet i have tig welded onto the compressor housing.

twin eng, twin turbs
05-09-2008, 10:45 PM
Heres a pic of the standard exhaust wheel before being modified.

Oneofthegreats
05-09-2008, 10:47 PM
Nice work.

I had Garrett make me a custom GT25/40 before they were released them along time ago now for my original plan's for my 20VT.

My plan's changed & now have a GT3076R, but I sold it to a mate & fitted it to his CA18 Bluebird & on 20psi made 197rwkw's & was an absolute animal on the street. Could light the tyres up in 3rd way past 100km/h!

Boost build up came on fast & strong & didn't let up. That turbo was designed for fast spool up & high pressure upward's of 26psi.

Look forward to hearing your result's & feedback on this.

twin eng, twin turbs
05-09-2008, 10:54 PM
This pic shows half way through machining out the exhaust housing to suit the much larger exhaust wheel of the GT 25/40. I ground an 2.0mm radius on the carbide tipped boring bar to suit.

twin eng, twin turbs
05-09-2008, 11:05 PM
Heres the much larger Gt 25/40 exhaust wheel in the VF22 exhaust housing. I gave it 0.40mm clearance to the on each side so when the wheel heats right up it will not scrub the bore. This is the same clearance as garrett housings have. Note the back cutting on the wheel which improves its efficiency at high speed and flow rates.

twin eng, twin turbs
05-09-2008, 11:26 PM
After blowing exhaust gaskets numerous times due to the excessive heat i decided to increase the surface sealing area around the exhaust housing and also add another bolt hole where the gaskets were leaking. If you compare with the first pick in the series you can the difference where i have built up the sealing area with weld and added the extra bolt hole. Here i am clocking up the flange for machining.

twin eng, twin turbs
05-09-2008, 11:32 PM
milling in progress for a hopefully leak free future!

twin eng, twin turbs
05-09-2008, 11:42 PM
:biggrin:
Nice work.

I had Garrett make me a custom GT25/40 before they were released them along time ago now for my original plan's for my 20VT.

My plan's changed & now have a GT3076R, but I sold it to a mate & fitted it to his CA18 Bluebird & on 20psi made 197rwkw's & was an absolute animal on the street. Could light the tyres up in 3rd way past 100km/h!

Boost build up came on fast & strong & didn't let up. That turbo was designed for fast spool up & high pressure upward's of 26psi.

Look forward to hearing your result's & feedback on this.

Cheers golfworxs

I am running a GT 25/40 on my Audi A4 aswell and even though its a family car it loves to boost up! I am also building a no expense spared 2.1 litre 16v with a customised GT 35r and an exhaust housing that flares out to a 4" down pipe

Mischa
06-09-2008, 12:17 AM
thats great stuff i hope one day i have the knowledge ( or at least some of it ) that you do, very inspirational. we need to hear more about your untold cars though!

mollins
06-09-2008, 09:45 AM
unreal mate. thats great work. very thourough.

i have tool envy...

twin eng, twin turbs
06-09-2008, 10:06 AM
unreal mate. thats great work. very thourough.

i have tool envy...

Cheers mate, do you remember that alloy cam cover i bought off you? Its in the first pic with the fins machined off and polished up! :biggrin:

abreut
06-09-2008, 06:46 PM
Nice work. I like it when people use some ingenuity to get more power instead of just forking out cash for new parts.

gldgti
07-09-2008, 06:22 PM
nice work mate - couple of questions:

1) is the exhaust housing material easily welded to? is it a simple mig job, or tig? what gas you using?

2) did you increase the turbine size purely for max output advantage? do you envisage a slower spool up now?


cheers

aydan

twin eng, twin turbs
08-09-2008, 08:40 PM
nice work mate - couple of questions:

1) is the exhaust housing material easily welded to? is it a simple mig job, or tig? what gas you using?

2) did you increase the turbine size purely for max output advantage? do you envisage a slower spool up now?


cheers

aydan

Yes the exhaust housing is easily welded as it is cast steel, and i simply "v" prepped it and mig welded it with flux cored 1.2mm wire and argo sheild as the sheilding gas. If the housing was cast iron it would still be weldable with eutectic spray welding techniques but this would not be as strong with less penertration into the base metals and the possibility of cracking occuring under the torque of the bolts through the flange. You can weld cast iron with a mig but it will crack! and it is very difficult to machine requiring industrial diamond ceramic cutting tips at around $300 each!

I have increased the turbine and the compressor wheel sizes and flow rate capabilities by a large amount in doing this modification but the size of the wheels is not as important as the design of them! The original vf22 turbo is the highest flowing of the vf range used on the wrx sti's but also the laggiest aswell, this is due to its 10 blade compressor wheel compared to 12 blades on every other vf series turbo. The Garrett GT i used has 14 blades and a more advanced design aswell for improved airflow. The exhaust turbine on the garrett GT is back cut for improved flow in the top end and has a more aggressive rack angle where the exhaust gas hits the wheel but it is a compromise between low rpm response and high rpm power flow. I envisage a little slower spool up but only by a maximum of 500rpm, it spooled up from 1500rpm in each gear with around 5psi at 2000rpm and had usable strong torque across the entire rev range. I am after more top end power for sure and peak boost from 4000rpm up to 7000rpm of around 20psi. This should net 200 plus kw at the wheels, ill post a dyno print out when i get it tuned in coming months.

twin eng, twin turbs
08-09-2008, 08:42 PM
Nice work. I like it when people use some ingenuity to get more power instead of just forking out cash for new parts.

Cheers thanks mate!

gldgti
10-09-2008, 03:14 PM
Yes the exhaust housing........................................

thanks mate, very helpful. between mollins and i we have a few turbo parts lying around now, and i'm curious to start playing around with stuff.

now knowing the specifics of the turbine wheels you're dealing with, your logic about retaining a good spool up becomes more obvious to me. cheers.

next time i'm out at orange i'll have to meet up with preeny and yourself for a chinwag.

Jarred
10-09-2008, 05:18 PM
*watches with intrest*

defiantly want to keep an eye on this one. Good info here :)

twin eng, twin turbs
11-09-2008, 10:17 AM
thanks mate, very helpful. between mollins and i we have a few turbo parts lying around now, and i'm curious to start playing around with stuff.

now knowing the specifics of the turbine wheels you're dealing with, your logic about retaining a good spool up becomes more obvious to me. cheers.

next time i'm out at orange i'll have to meet up with preeny and yourself for a chinwag.

Yeah for sure, allways keen to talk dubs and performance mods. We could go for a cruise aswell. Cheers

twin eng, twin turbs
25-09-2008, 07:09 PM
Just a update, everything has been back together for a week now and going harder than ever before with boost on only 13psi. In the first two gears it makes a bit more power than before but once into third the turbo gets loaded up and the rate at which it excellerates is unreal hitting redline in a few seconds and forth much the same. Before i turboed the car it would hit a wall of aerodynamics at 170km per hour and slowly gain speed to a 195km but now it hits rev limiter in fifth at 7200 rpm with a 020 16v box, on a closed road of course..... Heres a pic showing the size difference in compressor wheels from before and after. I couldn't photograph the machining as the camera was flat when i did it.

twin eng, twin turbs
25-09-2008, 07:17 PM
In the pic above you can see the white on the side of the larger wheel from test fitting, seeing where it is to tight and adding clearance to the housing to get the profile just right. In this pic below you can see how much clearance isnt available when you install a turbo behind an 8v. If you look close you can see the 3" downpipe which is the size of the entire exhaust system i made.

ausgolfer
25-09-2008, 07:46 PM
I am also building a no expense spared 2.1 litre 16v with a customised GT 35r and an exhaust housing that flares out to a 4" down pipe
PICSORBAN!:biggrin:


Great work, looks fantastic and the results sound the same.

twin eng, twin turbs
25-09-2008, 08:02 PM
PICSORBAN!:biggrin:


Great work, looks fantastic and the results sound the same.

Im just unwrapping my polished four pot calipers all round for the scirocco that arrived today from the states hmm :biggrin: wants some pics?

Mischa
25-09-2008, 08:03 PM
Im just unwrapping my polished four pot calipers all round for the scirocco that arrived today from the states hmm :biggrin: wants some pics?

man we need pics and details of all these secret projects of yours!

twin eng, twin turbs
25-09-2008, 08:21 PM
man we need pics and details of all these secret projects of yours!

In good time, i will do a thread on the full restoration of the scirocco and the chopping up of its floor pan! When i fit a Audi S3 driveline!

Mischa
25-09-2008, 08:23 PM
In good time, i will do a thread on the full restoration of the scirocco and the chopping up of its floor pan! When i fit a Audi S3 driveline!

btw why 4pots all round? isnt that overkill on the rear? and if its not, then why are the fronts only 4 pot lol?

twin eng, twin turbs
25-09-2008, 08:29 PM
The fronts run much larger pistons than the rear and with adjustable bias i can set it just right. It may seem like overkill but im building what should be a 10 sec 1/4 car with hillclimbs, track days etc being my aim i want the best i can afford to fit...

mollins
26-09-2008, 11:00 AM
Cheers mate, do you remember that alloy cam cover i bought off you? Its in the first pic with the fins machined off and polished up! :biggrin:

good to see something put to good use!

glad to hear the turbo gets you the power you wanted. Would be great to have that power bump with such a minimal increase in weight. Sounds like you will have plenty of fun on that closed private road of yours. :driver:


man we need pics and details of all these secret projects of yours!

mischa.. this guy is nuts.. im still hoping one day he'll post some more info about his twin eng mk1 and his crazy mk2 (with pics). he loves to keep us hanging.

btw. im definitely coming with aydan when he heads up to orange sometime! hopefully when the mk1 is finished!

Jarred
26-09-2008, 11:09 AM
Dude, I'm totally roadtripping up to orange after exams!

I WANT SOME PICTURES!

scirocco with S3 driveline?!?!

Twin engine mk 1?!?!?

Crazy mk 2!?!? Dude... pics, like really. STAT!

hahah, no pretty please.

Preen59
26-09-2008, 05:51 PM
mischa.. this guy is nuts.. im still hoping one day he'll post some more info about his twin eng mk1 and his crazy mk2 (with pics). he loves to keep us hanging.

btw. im definitely coming with aydan when he heads up to orange sometime! hopefully when the mk1 is finished!

Haha i've seen all this stuff. Many times. :nana:

I'd rather my carbied NA engine though.... :nana: :biggrin:

Valver.
26-09-2008, 07:06 PM
man we need pics and details of all these secret projects of yours!

Don't we just ;)

twin eng, twin turbs
27-09-2008, 03:21 PM
Haha i've seen all this stuff. Many times. :nana:

I'd rather my carbied NA engine though.... :nana: :biggrin:

HA HA! My mums mk1 is faster than your car for at least the next year before you get yours running..... :biggrin:

Preen59
27-09-2008, 06:44 PM
HA HA! My mums mk1 is faster than your car for at least the next year before you get yours running..... :biggrin:

Yeah whatever. I'm getting there.. :brutal:

richo
01-10-2008, 08:38 AM
I'll get photos of all this stuff and post it next week seeing as marty will never get round to it.:nana:

twin eng, twin turbs
01-10-2008, 10:33 PM
I'll get photos of all this stuff and post it next week seeing as marty will never get round to it.:nana:

Ha! heres some photos then, Starting with the massive turbo that will be helping make the 500hp goal power output from my 2.1 litre 16v. :biggrin:

twin eng, twin turbs
01-10-2008, 10:42 PM
Heres a shot of the 4" coned outlet on the well modified exhaust housing sitting on the 16v turbo manifold i made from scratch. You can see the ports which are polished all the way through on the manifold with webbing welded all the way between the runners to prevent any warping under the high temperatures it will endure causing leakage at the gasket to the head. I will get the manifold and exhaust housing high temp coated in the future... What isn't pictured is the 38mm tial wastegate to go with it all..

twin eng, twin turbs
01-10-2008, 11:01 PM
Heres the custom inlet manifold i fabricated. The runners are 56mm diameter at the plenum with bellmouthed ends tapering down to the oval shape to suit the ports of the head. At the head they are 6mm bigger in diameter than stock and ported, polished and port matched with dowels fitted so once in place the join is smooth without any step at all. The plenum is 100mm diameter tapering off at the end and i am currently machining up a billet 80mm throttle body to suit the manifold so they are matched. I will polish all of this once finished.

Oneofthegreats
01-10-2008, 11:05 PM
Nice work.

What model/spec is that turbo?

I like the pipe expansion. Just like a expansion chamber on a motorbike. My friend used this style on a FJ20 with a GT3540 in a mk1 escort with huge success & power too!

Just for interest sake, I personally wouldn't web a hig hp turbo exhaust manifold like that.

They do expand a fair bit & if there contained like that, they will crack elsewhere & in a bigger way. they'll also crack the hell out of the ceramic coating.

My race 4-1 pacemaker's on my old ute with high temp coating even cracked under the temp. put on it in a burnout comp!

The flange & stud holes should also be cut & separated from each runner for the same reason.


http://www.vwwatercooled.com.au/forums/images/imported/2008/10/1_8t20transverse201-1.jpg

twin eng, twin turbs
01-10-2008, 11:19 PM
Heres a pic of one of the front brake calipers for the scirocco that will require at least 17" wheels, custom mounts and 13" rotors to suit. All polished up its a willwood 4 pot with almost 2" diameter pistons. Should be up to the task! Thats all the pics i am sharing for now... :nana:

twin eng, twin turbs
01-10-2008, 11:41 PM
Nice work.

What model/spec is that turbo?

I like the pipe expansion. Just like a expansion chamber on a motorbike. My friend used this style on a FJ20 with a GT3540 in a mk1 escort with huge success & power too!

Just for interest sake, I personally wouldn't web a hig hp turbo exhaust manifold like that.

They do expand a fair bit & if there contained like that, they will crack elsewhere & in a bigger way. they'll also crack the hell out of the ceramic coating.

My race 4-1 pacemaker's on my old ute with high temp coating even cracked under the temp. put on it in a burnout comp!

The flange & stud holes should also be cut & separated from each runner for the same reason.


http://www.vwwatercooled.com.au/forums/images/imported/2008/10/1_8t20transverse201-1.jpg

I used 4mm wall thickness mild steel steam pipe bends for the runners for good reason. On my 1.8t audi a4 i made a similar manifold running a GT 25/40 turbo without any problem for years. Its so solid that it dosn't warp or crack. My mk2 has a similar set up with water cooling around the turbine flange which has kept the temps down preventing any cracks or gasket issues. After having made stainless manifolds in the past with thinner wall thickness (1.6mm) i have had issues with them cracking and flanges warping causing leaking gaskets. Thats why i make mine from mild steel with much thicker wall thickness.

Turbo is based on a GT35r with modified housings, ported and polished for improved flow etc

Oneofthegreats
01-10-2008, 11:49 PM
I used 4mm wall thickness mild steel steam pipe bends for the runners for good reason. On my 1.8t audi a4 i made a similar manifold running a GT 25/40 turbo without any problem for years. Its so solid that it dosn't warp or crack. My mk2 has a similar set up with water cooling around the turbine flange which has kept the temps down preventing any cracks or gasket issues. After having made stainless manifolds in the past with thinner wall thickness (1.6mm) i have had issues with them cracking and flanges warping causing leaking gaskets. Thats why i make mine from mild steel with much thicker wall thickness.

Turbo is based on a GT35r with modified housings, ported and polished for improved flow etc


Makes perfect sense.

The watercooling idea sound's like a beaut too. Would like to see some pic's of it.

I'm not a big fan of the stainless gear either.

All the the stuff I've been involved with has also been steam pipe straight from Reece plumbing. Strong, easy to work with & almost every bend you could ever need.

This is how I'd like mine setup on the "one day" 20vt.

Have the turbo hanging off the side, on top of the gearbox, shortening the pressure piping by at least a foot, reducing the exhaust down pipe radius & also being able to get fresh air straight into it.

Only draw back is relocating the booster/master cyl. assembly remotely.

http://www.vwwatercooled.com.au/forums/images/imported/2008/10/Exhaust1-1.jpg

http://www.vwwatercooled.com.au/forums/images/imported/2008/10/21-1.jpg

twin eng, twin turbs
02-10-2008, 12:04 AM
That looks awesome! you have been putting a lot of thought into this... I made a similar manifold setup on a nissan ET pulsar running a CA18DET with a t3/t4 though the exhaust was at the front the 3" down pipe i had going over the gearbox and down.

One thing to consider is manifold length although tuned length is good the longer the runners are the less heat energy and pulse from the exhaust stroke hits the turbine. Shorter runners will have improved low end response but dont flow the top end nearly aswell as longer tuned length manifolds.

Preen59
02-10-2008, 12:04 AM
Autodesk Inventor CAD model?

Oneofthegreats
02-10-2008, 12:12 AM
Autodesk Inventor CAD model?

Nah matey.

Didn't mean to fool both of you.

Christ I'm not that good on a computer. Can't even circle item's in pic's or draw arrow's on photoshop!!!!

Found the pic somewhere, like the idea, design & thought it would work really well on a golf, due to turbo, intercooler & intake placement.

I didn't really matter about the tuned length runner's or the length. More placement.

I learn't from a friend who has alot do do with rotary's, that if it's all smooth & no sharp kink's, it doesn't matter about if there the same length or not. It will still work!

Look at how much power can be made on standard early headed cast holden v8's exhaust manifold's with a single turbo. 600+hp is easily achievable!

It's to run a GT3076R with a .82AR ex. housing by the way.

Golf Houso
02-10-2008, 02:32 PM
Looks like an auto-desk inventor jobbie, would love to see that in real life!

richo
09-10-2008, 08:25 PM
here are some pics now the mk2's back on the road.

Preen59
09-10-2008, 08:30 PM
here are some pics now the mk2's back on the road.

Richo??? The Mk2 looks like crap with those big bumpers hehe.. :nana: Just kidding. When are you gonna give me a spin HMMMMM?

richo
09-10-2008, 08:39 PM
ha preeny, it's rich (marty's bro)! i was down during the week. my A4 is in the background of one of the pics. he won't let me drive it, so good luck man!
cheers

gldgti
09-10-2008, 08:58 PM
I used 4mm wall thickness mild steel steam pipe bends for the runners for good reason.

- and its really easy to TIG at that thickness ;-)

seriously though, its great to see some proper fab happening.... very inspiring for me - i spend many mornings during my commute thinking of parts to make but just don't have the time.... gee its going to be nice when uni is finished...

gldgti
09-10-2008, 09:16 PM
It's to run a GT3076R with a .82AR ex. housing by the way.


oh is that all....you might aswell just do away with your engine completely, join the compressor outlet straight to the turbine inlet and start injecting kerosene!

mmm i love thinking about jet engines.... i mean big turbo's.

Preen59
09-10-2008, 09:20 PM
oh is that all....you might aswell just do away with your engine completely, join the compressor outlet straight to the turbine inlet and start injecting kerosene!

mmm i love thinking about jet engines.... i mean big turbo's.

Hahaha a bloke at work was making one of those!

twin eng, twin turbs
09-10-2008, 10:07 PM
Pics are outside my workshop and i can say my workshop these days as i got a promotion to workshop supervisor last week:biggrin:$$$$$$$ HE HE! Though pics are a bit average rich i still like em cheers bro!

Preen59
09-10-2008, 10:11 PM
Pics are outside my workshop and i can say my workshop these days as i got a promotion to workshop supervisor last week:biggrin:$$$$$$$ HE HE! Though pics are a bit average rich i still like em cheers bro!

Mustn't be much competition there huh? :nana:

Car looks good.

Oneofthegreats
09-10-2008, 10:45 PM
oh is that all....you might aswell just do away with your engine completely, join the compressor outlet straight to the turbine inlet and start injecting kerosene!

mmm i love thinking about jet engines.... i mean big turbo's.

Theres nothing extreme at all about that turbo.

That's a pretty common turbo for the 1.8T's, but the ex. housing normally used are the .68's

I think, if I ever get around to it, I'll downsize the ex. housing.

twin eng, twin turbs
10-10-2008, 02:47 PM
Mustn't be much competition there huh? :nana:

Car looks good.

Ha! If you ever leave the bludge that is electrolux, :nana: you are welcome to join my team.

gldgti
15-10-2008, 10:16 AM
Theres nothing extreme at all about that turbo.

That's a pretty common turbo for the 1.8T's, but the ex. housing normally used are the .68's

I think, if I ever get around to it, I'll downsize the ex. housing.

depends which side of the fence you sit on.... im used to little diesel turbo's that huff it up down low in the rpm range, so anyhting bigger than a T3 is big to me ;-)

from what i observe, it always seems that petrol cars have way too big turbo's fitted to them - but i guess thats a trade off between having low backpressure at high rpm and making boost.....

i tend to think that extreme is not having full boost at 2000rpm in any gear :-)

jasn78
15-10-2008, 04:48 PM
hey guys one question about highflowing is it worth doing to a k03s? just thinking rather than go k04 possible option? thoughts please

Eddy
15-10-2008, 07:55 PM
hey guys one question about highflowing is it worth doing to a k03s? just thinking rather than go k04 possible option? thoughts please

Hoyhoy.

Don't worry, you already have the KO3-S Jason.

twin eng, twin turbs
18-10-2008, 07:47 PM
hey guys one question about highflowing is it worth doing to a k03s? just thinking rather than go k04 possible option? thoughts please

I would steer clear of the any of the KO3 or KO4 range of turbos, but thats purely due to my preference for roller bearing turbos. The KO3 on my A4 1.8t would boost up straight off idle but run out of flow way before redline. I made an exhaust manifold and 3" exhaust to complement the Garrett GT 25/40 with a 0.60 air ratio compressor housing that i fitted to it. It starts to boost at 2000rpm and makes full boost at 4000rpm then its hold on time! But the low down drivability or lag that is associated with big turbos isn't a problem with a roller bearing turbo of this size. It all depends on your budget aswell...

DUB 20V
18-10-2008, 09:21 PM
I would steer clear of the any of the KO3 or KO4 range of turbos, but thats purely due to my preference for roller bearing turbos. The KO3 on my A4 1.8t would boost up straight off idle but run out of flow way before redline. I made an exhaust manifold and 3" exhaust to complement the Garrett GT 25/40 with a 0.60 air ratio compressor housing that i fitted to it. It starts to boost at 2000rpm and makes full boost at 4000rpm then its hold on time! But the low down drivability or lag that is associated with big turbos isn't a problem with a roller bearing turbo of this size. It all depends on your budget aswell...

do you run just the std smic on the audi?

Preen59
18-10-2008, 10:31 PM
do you run just the std smic on the audi?

Nah its got a big fat front mount on it. :)