Big, bigger, biggest......turbo!

[audiman]

Gearbox is the weak link in all this. The 5 speed is useless for massive power, it will destroy itself! BTDT. The S2 head IS exactly the same as the KR head (but longer!) so yes the cam gears for the 16v "should" fit. I dont of anyone using uprated driveshafts, but thats not to say that they dont break at high power.

I personally like having the failsafes of the motronic setup. Knock control, boost control etc etc. You never know when something could go wrong and hopefully with the failsafes it should minimalise the damage to the engine/turbo setup.

@wes, could you post some compressor maps up here for us to see on both your recommendation and also turbos such as the GT35/40R etc?

[whakiewes]

Tom,

I am trying to get a map of the T04R. Corrado was just about right on with the specs..the difference is with the T4 turbine, and you can get way more thrust on the huge compressor, so it flows a bit better. Its based after the HKS T04R setup used on several Supras. The highest I can find with a T04R is 715whp @ 28psi! GT30R, GT35R, GT40R. I don't have a T04R map right now, nor a PT70/71 map. Efficiency island should be close to that of a GT40R.





That is an interesting thought about big power out of these cars. I was under the thought that the 5-speed transmission was pretty strong, but I guess not. So what can you do? Contract someone like OSGiken to make a gear set for it? Quiafe? Any factory trannies that bolt up, up to the task? Do they break after hard launches, or just full boost runs? I ask because I don't drag race, so I won't be doing many launches if any at full boost.

I have used both aluminum and carbon fiber driveshafts before. Aluminums have held up fine, and so has carbon fiber. Cost on my CF one was ~$1100, and aluminum one was ~$800. Looking at the undercarriage of my car though, the driveshaft and rear axles look plenty up to the task. I've seen much smaller/weaker parts do 700whp on many occasions.

I pulled down my exhaust last night and saw that it runs up and over the axle. Has anyone ever tried running a straighter exhaust under the axle...I mean were not rallying. I am starting to build my exhaust today, and I might give it a try. I'm on stock suspension right now, and I doubt im going to be going offroad anytime soon, so it looks very plausible to me!

Wes

[S2 Ant]

I doubt anyone in the UK would look to going under the axle as the roads over here arent good at the best of times and our Government love to put speed bumps here there and everywhere, so clearance becomes a big issue for us, esp if its involving something like a 3" exhaust.

[dan_b]

You could look at a side-exit exhaust though which avoids going near the rear axle, some guys in the UK have done that? (although I personally don't like the look of it!)

[whakiewes]

not a big fan of the side exit exhaust. I guess I will see how low a direct rear exit will be, then go from there. That final 45 degree bend is pretty harsh!

[audiman]

From what i have heard there is a 5 speed strengthening kit carried out by MTM. But quaife etc dont do anything except ATB diffs. As for the exhaust under the axle, that is a big no in the UK. Side exit exhaust is a comprise, i dont like side exits, even though i have one.

The 5 speed boxes (S2) have a weak input shaft bearing and also the shaft snaps. Also the 5th gear is only pressed onto the shaft and this chews up with big power/torque.

The older 5 speed (016) is stronger, but has odd gear ratios, not all that great for 1/4 miles.

The 6 speed box is stronger but that also suffers from 2nd gear problems as the gear isnt very wide and cant take large power. You can use the 98- S4 gearbox as this is a bit stronger, but this also fails.

You just have to have deep wallets for gearbox repairs every 6 months or a year

[jogi730]

I have a video of a guy called Jonus doing a quarter in low 10's with 016 gearbox - not too bad I guess? No idea how to upload that onto here though. Anyone want to see it I can e-mail it to them.
Cheers
Chris

[audiman]

I think i may have got confused there with your g/box Chris? I dunno LOL

[jogi730]

LOL!
You're probably right there Tom, but this guy is in same car as mine using same g/b. Does a 10.07 1/4 with 239kph teminal speed.... Respect eh? not bad for a crapy box that isn't good for the strip ( I know I'm too happy with my box either, but no point changing it until it breaks)? Certainly something to aim for though
Cheers
Chris

[SteveH]

I pulled down my exhaust last night and saw that it runs up and over the axle. Has anyone ever tried running a straighter exhaust under the axle...I mean were not rallying. I am starting to build my exhaust today, and I might give it a try. I'm on stock suspension right now, and I doubt im going to be going offroad anytime soon, so it looks very plausible to me!

Wes

Why not use 4" or larger oval pipe ??

I've heard of one car with oval 4" pipe that goes over the rear driveshaft without fouling..

Steve

[Mihnea]

Antti,

I haven't disregarded your initial suggestion, however, that sort of thing is time consuming and I don't have that time just now...

If you say money is in 1.8ts and 2.7Ts, you just got me wrong, because I don't do this tuning thing for money, it is not my first goal in life. I only do this because I enjoy myself doing it and because I love tuning engines. Of course, if I hadn't spent close to €50k on most of the stuff that I know and hardware to do my job (properly I think), I'd just spread the information and knowledge about ECUs that I have gathered around and allow everyone to tune their own cars themselves, but I have to remain realistic and I also have bills to pay for every month, so I just can't do that sort of thing.

Anyway, yes motronic M2.3 and M2.3.2 can be mapped realtime, I have been doing so for almost 3 years now.... more recent motronics like ME7.x generally can't be mapped real-time, but this is not true in all cases, meaning I can map any ME7.x in full real time.

HTH,

Mihnea

billman, I know what you mean, I have same problem, the home made chips are not so versatile of tuning bigger injectors or after that making idle run better.

usually just little tuning more or less fuel, maybe tinkering with advances.

I took the hard road, bought an Haltech, run it with distributor.

E11 haltech should run I5 but i'm not the one to try it.
Finnish ecu Tatech should do the job also, and with reasonable price,
but yet again, I will not sacrifice my car and money to the testing.

kwlw: lisensing the tuning software and using standard copy protect bases would make the money flow to mihneas direction. The real money is 1.8t and 2.7t engines, giving up the knowledge of I5 will not hurt the business, only create more of it, but there is some kind of rule of the thump that people that knows they thing in cars, usuallu dont know anything about money, and vice versa.

[olsonjus]

The T04R/T3 is a great turbo for small high reving honda's. With our increase in displacement and exhaust gasses, I dont feel we can really take advantage of it as much as those guys. I feel you will see too much backpressure with the small stage 5 t350 turbine wheel that those use. A better option is to step up the turbine wheel size a bit.

A really good combination that spools almost the same as a the t04r/t3(also know as the t67/t3) is to retain the compressor wheel, but use the gt37's turbine wheel in a t3 turbine housing.

This turbo is known as a gt3767, and is sold by Precision turbo. This turbo will make almost as much power as the GT40R that I'm going to run. It has a bit smaller turbine wheel that will limit its power capability. I have seen 700whp on a honda with the
gt3767.

This turbo is also sold by Full-Race Motorsports. It is sold under the name of T3/T67HO. It uses the P trim turbine wheel that is virtually the same size as the gt37 turbine wheel.

http://www.full-race.com/catalog/product_info.php?cPath=214_162&products_id=468

[olsonjus]

Also, check out this to see how the t3/t67 performs.

http://www.full-race.com/articles/bushing_turbo_selector.pdf

[whakiewes]

I'm not turbo yet on my Coupe, so I am staying with a 2.5". I did some measuring, and it should be fine...I hope. Thanks for all of the suggestions though...

Offtopic, but does anyone know what all the hydraulic unit controlls? I found my mount had a crack in it today, and the dealer wants $100 for the mount...so I am trying to decide if I can just remove it as I have done many times with BMW's. I normally only have two lines in a BMW, and this unit has three.

Thanks,

Wes

[corrado]

Personally for anything over 650+ I would go straight with a GT42R with a 94mm wheel, there is plenty of room to grow aswell.

I might be geting an S2 witin the very short future and play around with it:mischeif: after I have completed what I have on my hands, should be fun .

The way I would route the exhaust if 4 inch or bigger if side exit is a no no is go until the middle of the car where the turn comes on and point it downwards so it faces the ground, it will be loud unless you find some 4 inch resonator silencer.