AAN into Ur quattro, 400-450 Bhp Target

[prj]

0.63 with stroker will just surge like crazy.

Drop your compression ratio, either by running a thicker gasket or by using custom pistons.
You will get gains before the turbo has spooled up, and after as well. You will gain all around in transient response, meaning better spoolup as a side effect.

Of course light load cruise and fuel economy will suffer a tiny bit.

[Jamo]

URquattroGus you should read Bram's thread, that is exactly why he changed. the 3071 is a great turbo but it is very on off in feel until it comes on song it's not very progressive.

I would say here a lighter flywheel and bottom end maybe in order or the ghetto stroker conversion

[DJones]

Lighten the bottom end, also see if you can add more off boost advance.

[A80Avant]

as the exhaust ports get wider, spool drops instead of improved. However the idea of porting is that more flow+fuel equals more power, so when on boost it will make more power on every level when compared to the non ported head.

[K Simmonds]

Nice project. Don't think RS2 cams will help that much with spool up, the inlet is the same as ABY/AAN anyway and I'd have thought the exhaust makes most difference higher up the rev range. Head work would probably be the best bet, good quality porting by someone like JP would make a noticeable improvement to gas flow and therefore spool.

[A80Avant]

I had full boost with a bit of surge on higher gears on the 3071R 0.63ar, on stock head and adu cams at about 3500rpm on 3d and much sooner on higher gears. It did go out of breath after 5500rpm though. Porting is always good but might increase the spool times slightly.



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[URquattroGus]

Damo

I will try and get some better pics of the intercooler setup when I'm next with the car.

Interesting reading here.

So if I want to get my car to be more responsive lower down/improve the spool up and make it start lower, what are my options?

1) Get RS2 ADU Cams? I have standard AAN cams and comp ratio at the moment.

2) Port the head (expensive and time consuming) will this help a lot?

3) Change to a MD357 Turbo Dynamics turbo. There may be a problem here as I have a T3 flanged wagner Evo exhasut manifold. I went for the Gt3071 at the time as it was £850 and proven and the MD357 was £1300 and had only been used by one person.

4) Can anyone do some work on my existing GT3071R 0.63 to improve low end response?? (like the idea of this as it should be fairly plug and play?)

I can't/wont go for a stroker at this stage!

Here isn the dyno plot:



From the seat of my pants it doesnt really feel like it gets going until 3500rpm.

500rpm or more earlier would be nice. I feel this would make it more driveable on the road on corners as I can lean on it in a higher gear.

[DamoM]

1.6 bar turbo couldn't produced enough boost
I bought the engine in bits and rebuilt it from scratch

Just caught up on your thread! It's a monster!! Should see some nice figures with that.

[Jamo]

1.6 bar turbo couldn't produced enough boost
I bought the engine in bits and rebuilt it from scratch

[DamoM]

The spool is partly down to the turbo it has a very small turbine wheel 58mm IIRC but the 2.5 and 2.2 difference between the two cars can't be understated.

Pisobiker had the same spool as your car with an RS2 turbo, mine was 3200 rpm with a 3076r I could hit over 2 bar

So the cc is significant. What boost could he run on that RS2 turbo? You bought his engine did you not?

[DamoM]

Damo,

Is some of the early spool difference you refer to above, and in post # 84 between your Ur and your RS2, that Ur is a 2.5, and the RS2 is 2.2, if I read the detials in your signature correctly ?

Just slip this query in, what revs do you get fulll boost on the RS2 if it's 2500rpm on the Ur ?

Thanks, back on topic after your reply.

You're right the CC difference must be a factor too.

The RS2 full boost is 3000rpm. That 500rpm feels like forever, particularly in higher gears. UR revs to 7200. Don't think the RS2 is much more...

[Jamo]

The spool is partly down to the turbo it has a very small turbine wheel 58mm IIRC but the 2.5 and 2.2 difference between the two cars can't be understated.

Pisobiker had the same spool as your car with an RS2 turbo, mine was 3200 rpm with a 3076r I could hit over 2 bar

[macspring]

Fair enough. Must mainly be down to that turbo then!!

Damo,

Is some of the early spool difference you refer to above, and in post # 84 between your Ur and your RS2, that Ur is a 2.5, and the RS2 is 2.2, if I read the details in your signature correctly ?

Just slip this query in, what revs do you get fulll boost on the RS2 if it's 2500rpm on the Ur ?

Thanks, back on topic after your reply.

[DamoM]

ps you got any more pics of your intercooler set up?

re catch tank, we had to run a return out of it back into the sump (via a tube welded on to the dipstick) as it was filling it in one 10 minute track session! The vacuum off throttle sucks it all back in very quickly! Bit like a wet-dry sump system!

[DamoM]

Nice thread Angus. Great project. Car looks awsome.

Mine ran 455bhp and 670ish nm torque. I really think it's the turbo. I run the same Turbo Dynamics hybrid the Djones runs (ND357) and it really is a hell of a turbo. I have a tubular EM which helps but I get full boost (2 bar) at 2500 revs on the road which is way better than I could expect. On the track recently it was spinning the rear wheels with the torque out of tight hairpins. Great fun!!!

I have the same turbo on my RS2 and it doesn't spool anywhere near as quickly being barely better than standard so I'm guessing the reason for the quick spool up my be a mixtrure of head porting and tubular EM given that we had the same mappers....