Introductions, 20vt BTDT

**Doug_RS2** · 1 October 2004, 06:55

nice car - can you get me a cheap turbo?

I'm running close to 450bhp and with the last tuning session with Mihnea we raised the rev limit to 7800 rpm - He never told me what he did but I crapped myself when he told me to take it to the redline - It didn't sound right - it still pulled but I didn't like that - I thought the the general thought on hydraulic tappets is the 7600rpm limit I have just now is about the max they will go.

I am also changing to an AAN manioofld to replace the RS2 one I have - this is just to shorten the intake piping which will hopefully help with some lag. I have chopped the throttle body off and moved it to the front and removed the access runners to the bolts - I have copied Mark H on here - sounds like he got some serious lag reduction doing this.

Can I ask why you have those quick release brackets on the turbo to downpipe?

**S2central.net** · 1 October 2004, 08:56

The T04e is a good turbo for the S2 engine. MarkH uses one - with the 57 trim compressor IIRC. But I'm doubtful it can make 500bhp. Marks got to 400bhp on the 1st iteration (with RS2 IM and stock bottom end) but since the modded AAN manifold it has been remapped to cater for the exotic pistons and rods installed. Dunno what power he has now - its gotta be ~450bhp territory I imagine.

There are two benefits with the AAN style inlet manifold -
1. Reduced pressure drop and lag by having a shorter intake tract
2. Reduced air temperature by nature of the intake tract avoiding that toasty adventure over the hot side of the turbo

I think you can probably hit 500bhp with hydraulic lifters by running with a larger turbo - like a GT40R !

I don't think the hydraulic lifters like running much past 7500rpm as Doug says.

You could go with solid lifters along with an exotic lightweight bottom end to get into 8000rpm territory, but the costs could be frightening.

Paul

**SteveH** · 1 October 2004, 09:33

Originally posted by Doug_RS2

Can I ask why you have those quick release brackets on the turbo to downpipe?

Doug,

That's the V Band compression fitting you see on some of the Garrett turbos.

**JSHADZI** · 1 October 2004, 15:26

Originally posted by Doug_RS2

nice car - can you get me a cheap turbo?

Hello Doug, thanks for the reply, yes, well, a very quality turbo too, fell free to shoot me an email to discuss more

I'm running close to 450bhp and with the last tuning session with Mihnea we raised the rev limit to 7800 rpm - He never told me what he did but I crapped myself when he told me to take it to the redline - It didn't sound right - it still pulled but I didn't like that - I thought the the general thought on hydraulic tappets is the 7600rpm limit I have just now is about the max they will go.

Ok, so are we talking 450 wheel hp? My motor will easily rev to 7800rpm and beyond, see the attached dyno plot, the power has barely peaked and wants to kee going.

I am also changing to an AAN manioofld to replace the RS2 one I have - this is just to shorten the intake piping which will hopefully help with some lag. I have chopped the throttle body off and moved it to the front and removed the access runners to the bolts - I have copied Mark H on here - sounds like he got some serious lag reduction doing this.

Yes, this is where I believe there are some gains to be had, anyone actually done a back to back comparo with results? Sometimes its hard to isolate mods. but it would be great if someone had that experience.

Personally, I'm not a big believer that marginally shorter intake plumbing makes all that much difference, I've done many turbo system installs and played with intake plumbing volume, the results have been minimal in my experience.

Can I ask why you have those quick release brackets on the turbo to downpipe?

Sure, the downpipe comes off by loosening one clamp, very easy. "Quick Release" as you say

Attached Files

80tqDyno092204_375.jpg (84.9 KB, 360 views)

**JSHADZI** · 1 October 2004, 15:43

Originally posted by S2central.net

The T04e is a good turbo for the S2 engine. MarkH uses one - with the 57 trim compressor IIRC. But I'm doubtful it can make 500bhp. Marks got to 400bhp on the 1st iteration (with RS2 IM and stock bottom end) but since the modded AAN manifold it has been remapped to cater for the exotic pistons and rods installed. Dunno what power he has now - its gotta be ~450bhp territory I imagine.

Well, let me explain a little more. The compressor on the turbo I'm running is a .60AR T04E compressor, but with a GT40 compressor wheel installed. This turbo should easily flow 65 lbs and 500+HP.

There are two benefits with the AAN style inlet manifold -
1. Reduced pressure drop and lag by having a shorter intake tract
2. Reduced air temperature by nature of the intake tract avoiding that toasty adventure over the hot side of the turbo

I'm not too concerned about reducing intake plumbing lenth, and I believe what I have now is reasonable, and my air temps are more than acceptable out on the road. I plan on doing a little more shielding of the cross over pipe. I have plans to rebuild the intake manafold and relocate the throttle over in front of the radiator as has been done, but mainly I'd like to increase intake manifold volume and flow.

I think you can probably hit 500bhp with hydraulic lifters by running with a larger turbo - like a GT40R !

Wow, that's a very large turbo, have you ever seen one run on an I5? I have quite a bit of experience with the GT30R and the GT 35R. I've seen the 30 pushed to over 450whp, and the 35 to over 550whp. There are quite a few different trims and configurations available, I do believe the 40 is a little on the large side, especially the surge factor.

I don't think the hydraulic lifters like running much past 7500rpm as Doug says.

Yes, they have been fine to 7600 so far, I've even taken them to 8 once, but not sure how long they'll last up there

You could go with solid lifters along with an exotic lightweight bottom end to get into 8000rpm territory, but the costs could be frightening.

My bottom end is already somewhat "exotic", Eurospec rods (no problems with fit or performance), JE pistons, lightened, balanced, etc. I'm confident this bottom end will go to 9k should I need it, BTDT. The real weakness is the lifters, so I have the choice to either build a solid lifter head or tweak my cam timing to bring the powerband down some.

Here are a couple videos of the car accelerating, the first a 1-2 run, and the second a 2-3 run:

http://www.034efi.com/Movies/80tq20v1_2.avi

http://www.034efi.com/Movies/80tq20v2_3.avi

Thanks for all the dialogue!

**audiman** · 1 October 2004, 18:08

Solid lifters are a must to rev over about 7600rpm reliably. The hyd. ones will go over put for how long?? Plus hyd. arent an exact science. Solid lifters will keep the valve clearance a lot better, thus improving the power.

Short intakes will reduce lots of lag. I have a std 3B manifold with custom pipework onto a massive IC. The lag is there, but the intake temps are low. It would help with the lag, but IMHO not much else.

I see you already have a decent ex. manifold. So not much to gain from that. Doug and myself are still using RS2 ex. manifolds.

**Doug_RS2** · 1 October 2004, 23:54

Originally posted by JSHADZI

Ok, so are we talking 450 wheel hp? My motor will easily rev to 7800rpm and beyond, see the attached dyno plot, the power has barely peaked and wants to kee going.

Yes, this is where I believe there are some gains to be had, anyone actually done a back to back comparo with results? Sometimes its hard to isolate mods. but it would be great if someone had that experience.

Sure, the downpipe comes off by loosening one clamp, very easy. "Quick Release" as you say

what does whp mean - is the wheel as in road wheels or flywheel? I have close to 450bhp at the flywheel.

I would like a turbo capable of giving me more torque and more top end - My aim is over 500bhp. I only have an RS2 EM so I don't think that is good for 500bhp - but do your turbos bolt straight to a RS2 EM?

What would you recommend for that ? I see you have tubular manifold - do you sell those as well?

Mark H on here has had a normal intake and changed to the short intake - I think he said it made a huge difference to lag.

**JSHADZI** · 2 October 2004, 04:45

Originally posted by Doug_RS2

what does whp mean - is the wheel as in road wheels or flywheel? I have close to 450bhp at the flywheel.

I would like a turbo capable of giving me more torque and more top end - My aim is over 500bhp. I only have an RS2 EM so I don't think that is good for 500bhp - but do your turbos bolt straight to a RS2 EM?

What would you recommend for that ? I see you have tubular manifold - do you sell those as well?

Mark H on here has had a normal intake and changed to the short intake - I think he said it made a huge difference to lag.

Yes, whp means "Wheel Horsepower", on the dyno I tune on a 25% correction figure is commonly accepted, 20% to be conservative. So you could say I'm pushing about 450 crank HP right now. All my testing is at sealevel, no SAE correction figures.

I can provide you turbos that use the K26 turbine housing with various turbine blades fitted, anywhere from 45mm to 65mm. Yes, these bolt directly to the RS2 or any KKK equipped exhaust manifold. As you know, turbocharging is a trade off. Larger turbines and compressors flow more air but push the power band higher, making more HP and less TQ. Smaller turbines and compressors shift the powerband lower, giving strong TQ figures, but often hurting HP #'s. All depends on what you'd like to accomplish.

I for one don't mind waiting until 5500rpm, and revving to 7800rpm, making power the whole way there.

I'd love to know more BTDT (been there done that) experiences in changing over to free-er flowing intake manifold designs.

Thanks,

**Josh-stateside** · 2 October 2004, 04:55

Some of the custom intake manifolds I have scene.

Cheers
Josh

Some of these guys are on this forum too.

**Mihnea** · 2 October 2004, 05:30

Hey Javad, meet the S2Forum, and please behave

Talk to you soon buddy

Cheers,

Mihnea

**audiman** · 2 October 2004, 11:49

I want that Dalhback one :'( Gonna have to borrow some money and buy it!

**audiman** · 2 October 2004, 11:57

Any details of that top cars ignition system???? My original ign. system is coping fine with 2.1 bar boost, but im thinking about changing it to coil per cylinder

***Greg_S*** · 2 October 2004, 14:06

I was just looking at that ignition system too, was wondering how its all connected up?

Greg

**JSHADZI** · 2 October 2004, 19:57

Originally posted by Greg_S

I was just looking at that ignition system too, was wondering how its all connected up?

Greg

Probably running some sort of stand alone, you can see my coil setup running the 034efi Stage IIc, very easy to set up, will fire virtually any 2 or 3 wire coil: http://www.80tq.com/gallery/Progress...SCN0845?full=1

I suppose you could get the Motronic to fire coils like that as well.

Introductions, 20vt BTDT

Introductions, 20vt BTDT

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