500hp turbos- part 2

[diesel des]

An EVO seems good at turning air into bhp. The old i520vt less so. So it might be able to do 550 on an EVO but not do much more than 500 on the i5. Of course with a built modified i520vt more than 500bhp on a gtx3071r seems possible to me.

[diesel des]

The problem that I see are guys like me that want to have power between 550hp and 600hp, you have to go higher has a GT30 and lag will increase dramaticly.

Going to over 500bhp on a 2.2l engine will always mean compromises have to be made. That's over 200bhp per liter. You give up bottom and mid range for top end. Only increased displacement can help. That and more modern turbos. But they arnt miracle workers.

As prj has said. Anything over a gt3076r sized turbo on a 2.2 20vt is a drag car only. Some people will disagree but once you get the holset hx40 or gt35r sized turbos on a 2.2 your really into high mid to top end only power.

Some people will be willing to put up with a peaky motor that needs revved to perform, and will actually call that fun, but for a road car it's often better to loose 50 or even 100bhp at top end to have more usable mid range grunt. Round town a 3.0 tdi quattro would spank most gt35r cars of twice the bhp simply because the power is just there and so use able. Sure on a open road the tdi will disappear backwards fast. It's all down to what the driver wants and finds fun to drive. Again this is why lots of people find chipped rs2 setups so good. Plenty of torque and midrange grunt.

[S2central.net]

I think the above is the single most sensible summary on this topic I have seen for a long time... all of this turbo tuning malarkey is about compromises for different goals.

For me personally, I would take monster mid range torque and drivability over max power, but thats not going to win me any kudos down the 1/4 mile (or the pub with bragging rights over the real men with gazillion bhp 20VT dragsters).

[Quattronaut]

There is one thing you forget, and that is octane based dynamic compression limitation...couple of solutions - one is lowering the compression ratio...at least need 7A cams and a stacked headgasket would not go amiss...

You´re right; I just didn´t mention it ´cause I expected any interested people to know that. I changed the opening post; please have a look.

other one is moving the powerband higher into the revrange

Limitted through hydros, but yes, having to much torque in lower rpm does not only kill rods, but also knocks easier.

Thinking about this more maybe we need to make 2 lists...Thoughts?

IMHO it will be very hard to define the lists because there is so much stuff that CAN be done; that´s why I just added the REQUIRED things in my first post. Here I would concentrate on the turbocharger that are able to do that; mentioning all surroundings will blow one thread.

[Quattronaut]

Going to over 500bhp on a 2.2l engine will always mean compromises have to be made. That's over 200bhp per liter. You give up bottom and mid range for top end. Only increased displacement can help. That and more modern turbos. But they arnt miracle workers.

As prj has said. Anything over a gt3076r sized turbo on a 2.2 20vt is a drag car only. Some people will disagree but once you get the holset hx40 or gt35r sized turbos on a 2.2 your really into high mid to top end only power.

Some people will be willing to put up with a peaky motor that needs revved to perform, and will actually call that fun, but for a road car it's often better to loose 50 or even 100bhp at top end to have more usable mid range grunt. Round town a 3.0 tdi quattro would spank most gt35r cars of twice the bhp simply because the power is just there and so use able. Sure on a open road the tdi will disappear backwards fast. It's all down to what the driver wants and finds fun to drive. Again this is why lots of people find chipped rs2 setups so good. Plenty of torque and midrange grunt.

That´s perfectly right. I just added it in post 1: the 500hp mark is the last one that does make sense,esepially with hydros. All over that is drag or freaks

To be realy honest, the sense-limit for daily driven is still lower: Most Audi-upgrade parts, like RS2 IC, Cams, injectors are maxed out between 420 and 450 hp. For more, you have to buy bigger aftermarket equipment, which often is so big, that it is capable up to 600 hp; costing far more money, no OEM look, no plug´n play. So th best mark for real daily driven is around 450 ps, with full boost to be reached at around 3500rpm and peak power around 6500.

[popdemonic]

i totally agreed with choosing turbo depends on what's the purpose of the car.if you want it to be street driving,you defo need to look for a quick spool turbo.horsepower is always nice but driveability is something you also need to take into account.I have 2871 for a DD.i love the way how it spools up though the top end is down on its face.i'm also looking to something bigger but worried about losing the low-mid end.i don't care much about the peak horsepower on the 6000-6500rpm since i rarely use it on DD.if i would choose again i might be considering HX35 since the turbo is the best bang for the bucks though it slightly spools up later but she's still acceptable for driving in town.HX40 or 3582 is way far too big on my driving purpose.

[diesel des]

I also ran the gt2871r and then the gtx2867r. Both are great daily driver turbos. The gtx2867r does have more mid range.

I think going to the hx35 will be a big difference in response compared to the gt2871r.

[snp10]

In all this posts I did not read anything about ALS system. Is true that 500 hp and gt3076 is max for street driving, but there are cars with big turbo and over 600 hp , using Als , that can be drive with best performance on the street or track, not only drag racing.

[Rocco]

Budget increasing...

[snp10]

Is not so expensive for the results. Also we invest a lot of money in this projects, so 1000 euro + or - is piece of cake )

[Error404]

ALS is massively destructive to engine & turbo, so hardly useful for a street car. Off topic anyway for this thread

[snp10]

It was only a point of view for big turbo and good performance.
Offtopic -I asked some guys that partcipate at rallys with subaru and they agree that with ALS you can destroy the turbo but not so fast. I am thinking that if we construct 500 hp engine we don't race in traffic. For this there is tracks.

[Rocco]

i have driven 3 cars on the streets with +500bhp, GT3076 and GTX3076 turbos, and to be fair, i think is more than enough (fast and dangerous ) to be on the normal roads with traffic....

[driftin jo]

If you want big power, good response, with a big turbo, nitrous oxide is you friend

[Quattronaut]

Hey SNP10, if I got birthday nex week, you gonna send me one of those "pieces of cake" as present?

ALS Systems are expensive, loud and in most countries illegal on street. And they are not a turbo ;-)
I really think this is to freaky for daily drivers and road cars.