What turbo to put in the RS2?

[hoffer76]

k24 7200 hybrid setup runs 395bhp 650nm with standard rs2 injectors

k26/27 hybrid will run 420bhp 700nm using delphi or larger injectors.

but you are right the maf is the problem over 400

[prj]

k24 7200 hybrid setup runs 395bhp 650nm with standard rs2 injectors

Do you have a plot to show for this?

k26/27 hybrid will run 420bhp 700nm using delphi or larger injectors.

but you are right the maf is the problem over 400

a) You can't just swap injectors on Motronic. ME7.1 has fuel-trims that encompass the entire range, M2.3.2 hasn't. As soon as you go out of lambda regulation, it goes open-loop.
If you fit bigger injectors than what the software is made for, you are running rich all the time.
b) MAF runs out at 350hp. So you are mapping the 70 last HP to the last cell? An AFR graph won't be pretty with a such map.
c) MAF breaks over 400hp and keeps breaking.

Not trying to diss anyone, but I don't like butt-dyno numbers and estimates without proof.

If you guys think you can have real and reliable 420hp on stock motronic by just popping some chips in, then you live in a fairytale.

[Costash]

http://www.s2forum.com/forum/showthread.php?t=42601&highlight=rs2+hybrid

this it is just a part of proof because he didn t use 98 octane and rs2 ex cams.

[prj]

http://www.s2forum.com/forum/showthr...ght=rs2+hybrid
this it is just a part of proof because he didn t use 98 octane and rs2 ex cams.

I don't see any proof in that thread?
Only butt dyno discussion.

P.S.
I have mapped plenty of cars with K26/K27 hybrids. So one could say I have a little experience.

[Costash]

there is a dyno sheet somewere in there?!!Check that!http://www.s2forum.com/forum/showthr...ght=rs2+hybrid
Sorry wasn t in that link

[Ross]

Looks for the purpose of the thread, to me that the options are pretty much:

(1) Stock RS2 turbo @ 380hp
(2) Hoffer RS2 hybrid @ 395hp (similar range to stock?)
(3) K26/7 hybrid @400-420 with bigger injectors (later spool)
(4) Ditch the KKK and go for something exotic to fit requirements

My old GT3071R (430hp) setup was going to have the MAF relocated to the pressure side, i assume higher pressure = less velocity = less risk of failure at >400hp? I also had to upgrade injectors as the RS2 were not capable of >400hp. The bigger ones were maxed out as it was... my RS2 EM and RS2 IM were also pushing the limits.

For me it looks like the RS2 limit is 390-400hp before you start changing parts over stock. With injector upgrade only about 420hp, which is pretty proven over the years, but thats pushing it. After that you're needing to change alot of parts.

[prj]

My old GT3071R (430hp) setup was going to have the MAF relocated to the pressure side, i assume higher pressure = less velocity = less risk of failure at >400hp? I also had to upgrade injectors as the RS2 were not capable of >400hp. The bigger ones were maxed out as it was... my RS2 EM and RS2 IM were also pushing the limits.

Pressure side = complete remap needed.
And it STILL won't read above 350hp. So you are still running like 20% of the engine power off the last cell with the same settings.

For me it looks like the RS2 limit is 390-400hp before you start changing parts over stock. With injector upgrade only about 420hp, which is pretty proven over the years, but thats pushing it. After that you're needing to change alot of parts.

I don't see how 420hp is proven with injector upgrade.
The only thing that is proven many times by various people is that the MAF fails over 400hp and keeps failing.

If you want it reliably - HFM5. That'll be hopefully on offer in the UK as well.

[prj]

there is a dyno sheet somewere in there?!!Check that!http://www.s2forum.com/forum/showthr...ght=rs2+hybrid
Sorry wasn t in that link

That sounds about on target. 390hp.
But you can reach almost 390hp on stock RS2 turbo with aggressive mapping.
Plus, it's unknown what correction factor that dyno used.
And no, using 98 octane or RS2 exhaust cam will not magically bring you 30hp without a remap. Not even close.

This shows exactly what I have been saying.
K26/K27 is a good upgrade for a stock AAN. But fitting that instead of an RS2 turbo is madness. You will gain maybe 20hp extra.

P.S.
The turbo is not maxed out at 390 hp, but if you want to take advantage of it, you will need a custom map.
Generic remaps have way too much leeway built-in. Every engine wants a bit different settings, so it has to cater to the worst ones.

[Jeffer]

For me that dyno sheet has still to much lag in it. 3300ish full boost is to late for me. Mu old k29 with tubular spooled at 3500.....

[prj]

For me that dyno sheet has still to much lag in it. 3300ish full boost is to late for me. Mu old k29 with tubular spooled at 3500.....

It's more like 3900 full boost on that dynosheet.

I don't think there's much you can do really.
The RS2 turbo is a damn fine turbo, matched exactly to the engine.

The only other thing you could do is go 3071. But to map that to the full potential you would also need to get rid of the stock MAF.
Here is a graph from the HX35:

http://mulk.planet.ee/S4_hx35super.pdf

But that engine is quite developed.

Looking at your signature - you have written that your car is stock.
Have you considered just getting it custom-mapped on the dyno? You can get close to about 385hp that way.

[Jeffer]

I'm going to use VEMS so I don't need a maf.
So if we talk in terms of 420 HP and quick spoolup, cozs thats what I'm after, what would be the choise. Compturbo garret sounds best to me tbh. Ok, waterlines and oil lines need to be changed, but i don't really bother about that, i just want the best performance within this range.

[Ross]

Pressure side = complete remap needed.
And it STILL won't read above 350hp. So you are still running like 20% of the engine power off the last cell with the same settings.

I don't see how 420hp is proven with injector upgrade.
The only thing that is proven many times by various people is that the MAF fails over 400hp and keeps failing.

If you want it reliably - HFM5. That'll be hopefully on offer in the UK as well.

Perhaps I should be clearer - I'm talking about the bottlenecks that have been established over the years of projects on this forum. Of course, stick injectors and map on your stock RS2 = 420hp is not what I'm saying. But like I found, even with a decent clutch, exhaust, turbo, fuel pump, and RS2 engine components... I had to change the RS2 injectors to break that magic 400hp barrier and hit 428hp, where I started to hit other bottlenecks. If the wagner kit had been available at the time I'd have been fitting it...

Now I'm in Jeffer's situation, with a tweaked RS2, and some experience, I've set my aim at 390-400hp for reliability. If I wanted 420+ I'd be fitting some wagner kit and probably getting rid of the airbox.

Any more info on HMF5? Excuse my ignorance but what benefits does this give - my RS2 has output 375hp for 70,000 miles with a previous owner reliably. Is it 'guess work' over 350hp rather than an accurate and efficient map? And when/where can I get one...

[prj]

From Garrett - GT3071 or the same from HTA.

[prj]

Any more info on HMF5? Excuse my ignorance but what benefits does this give - my RS2 has output 375hp for 70,000 miles with a previous owner reliably. Is it 'guess work' over 350hp rather than an accurate and efficient map? And when/where can I get one...

Yes, it's basically guesswork.
Or rather, your engine runs off the same injector pulsewidth and same timing over 350hp, since motronic doesn't know anymore how much air is going into the engine.

And yes, it'll run fine at 375hp.
But going to 400hp from 375hp will be barely noticeable.
Going from RS2 turbo to K26/K27 will be utterly pointless, because the car's overall driveability will be worse.

So where could you go to? GT3071.
If you want to keep Motronic, then you need a MAF upgrade. The HFM5 is Bosch's MAF that uses a hot film rather than a hot wire.
It does not require a burn-off sequence, it is cleanable and it does not break because of too much airflow.
The HFM5 I am using is from the RS4 in the B5 chassis. It is about 90mm in diameter, so can be used in conjunction with a 3.5" filter. It reads to about 600hp crank and poses less airflow restriction into the engine than the stock MAF.

Over the summer, I will develop a few bolt-on kits with that MAF. But if you want it right now, the only option is to fly me over, because no one else has made the stock ECU work with this kind of MAF in 10 years. Why - perhaps it wasn't worth the effort or perhaps because it actually involves rewriting code inside the ECU. Not just changing calibrations.

[Jeffer]

Ross you are right, past 400 is pushing the stock RS2 components. But here's where I come from. I was balancing between 2 thoughts. one was to put my complete setup on from the S2 on the RS2. manifold, turbo, intake, IC, injectors, mapping etc etc. I've still got these parts. This however makes it an extreem car again, with everything that comes along with that. Then my other thought would be to keep the RS2 look under the hood and modify the bits to make reliable 420 hp with quick spool. Also this car is my "daily" so I want it reliable. Here's the list I have in mind and stuff I have, and wich I can use.

3" exhaust with DP
650 cc injectors
Vems ecu, so no MAF
larger IC
044 pump
spm rods
engine overhaul
RS2 em, or I can make a highflowing tubular manifold with turbo combo that still fits under the airbox. Wich will be tight, but will help spoolup....
Keep the original Xm and porsche IM for oem looks.

I think the best bet would be a gt3071r. People have had nice results with this setup, i was just wondering if there has come e new "rs2" upgrade favorit equivelent....