65 replies to this topic

[Lister]

Could the cat be partially blocked? This would severely restrict power.

[Evo-00x]

When I find out more I'll let you guys know but they want to consult Mark at GTPumps first about the mods done to the turbo and see if it can be tested.

[DOUGMO]

just to add to this,

what sort of mods are people doing to the rear end of the turbo on 20g's

anything?

better housing?

cut back wheels?

bigger wheels?

[GSRWRC]

just to add to this,

what sort of mods are people doing to the rear end of the turbo on 20g's

anything?

better housing?

cut back wheels?

bigger wheels?

Mine has a 7 degree backcut

[MADVR4]

what ecu? 510's arent gonna be enuff....

the turbo should be fine for atleast 200kw.... id say get some 700cc Sards and ecu... and increase the boost... if the engine has been built then boost isnt an issue its ur fueling and most likely the cams...

turbo is ur last thing...

Grant

[CLuTZ]

what ecu? 510's arent gonna be enuff....

the turbo should be fine for atleast 200kw.... id say get some 700cc Sards and ecu... and increase the boost... if the engine has been built then boost isnt an issue its ur fueling and most likely the cams...

turbo is ur last thing...

Grant

I made 216kw atw with 510's, and I rekon they're good for 220 at least

[Evo-00x]

He has a got a Haltech E6X and Micks Motorsports is doing the tuning. As stated, he reckons the 510's are still fine and there was no need to upgrade them yet (easy to do just by bolting on anyhow but he reckons no need thus far). Mick knows his stuff and by the looks of it the TD06 20G hybrid is getting ditched now anyway for something bigger anyway.

[steve]

GT3076 by any chance?

Mick loooves that turbo after mine and GUN20T's results with them on 4Gs.

[matress]

I doubt the 510's are the problem... plenty of us have made over 200kw at the wheels with similar or the same injectors.

[EVO85]

what ecu? 510's arent gonna be enuff....

the turbo should be fine for atleast 200kw.... id say get some 700cc Sards and ecu... and increase the boost... if the engine has been built then boost isnt an issue its ur fueling and most likely the cams...

turbo is ur last thing...

Grant

I made 216kw atw with 510's, and I rekon they're good for 220 at least

Don't you have 216kw's at the front wheels? If its possible to make 293hp (215kw's) at four wheels, an easy 240kw's at the front wheels should be possible using 510cc injectors as there is less power lost through the drivetrain....

[Evo-00x]

GT3076 by any chance? Mick loooves that turbo after mine and GUN20T's results with them on 4Gs.

Yep, you got it in one dude and I dont blame anyone for going for a turbo like a GT3076. Its in between a GT3071 (aka GT28R) and a GT3082 (aka GT3040R). The next step after a GT3040R is a GT35R but on the boost pressures associated with pump fuel mate there's not much more to achieve by stepping up to the bigger ones.

[GSRWRC]

The next step after a GT3040R is a GT35R but on the boost pressures associated with pump fuel mate there's not much more to achieve by stepping up to the bigger ones.

Really? A mate of mine went from a 3040 to a 3540 and makes 338kW atw on pump 98. Chose the 3540 over the 3040 because of its better matched turbine and compressor wheels.

[Evo-00x]

Yep, but what was he making with the exact same setup and boost levels with the GT3040? Was it a bolt on comparison using the same size turbine housing? Dont get me wrong all cars are different and things such as intake and cams will make a difference, but in the lower boost levels there wont be much between these turbos. A friend in NZ advised me the following when he did his back to back dyno comparison which confirms similar:

"Here is the big one: Based on tuning my car today, I can say that switching from a 0.82 GT3040 to a 0.82 GT3540 will NOT gain you any more than a few (~3) kw at the boost levels run on pump fuel. (22.5psi)
It does however only loose about 250rpm of boost threshold, instead of the 500+ I expected. I was a bit disappointed, expected about 30kw more power. I'd imagine the gains would be at high boost levels, (28psi+) where there would be more of a difference in turbine inlet pressure, but that is race fuel territory. I'm actually starting to believe that if only pump fuel is to ever be run, a GT3076 (AKA GT3037, GT30R) will make 90% of the power a GT3540 will but with a much wider powerband."

His GT3040R produced 316kw (425 HP) ATW at 22psi on 98 octane, and made useable boost from about 3500rpm, and full boost (22psi) hit at about 4500rpm. At 14psi it made 250kw atw, at 18psi 285kw, and 21psi 305kw. All on 98 octane and a conservative state of tune. He is using Kelford 272 billet intake and 264 billet exhaust with mild dial-in (both 2 deg advanced). He said off-boost torque was almost same as stock and max power was at 7700rpm - and thats with the stock intake manifold.

Its good to see real life comparisons like this with the type of mods people use as it helps paint a better picture overall of the type of power you get with the type of mods you make. If your mate has a lot more mods or ran higher boost levels then 23psi on 98 pump then you would expect a bigger figure from the GT35R. The GT3040 mainly has problems with compressor surge if someone is using a 0.64 turbine housing so use of a 0.82 or bigger is recommended with them.

[steve]

Really? A mate of mine went from a 3040 to a 3540 and makes 338kW atw on pump 98. Chose the 3540 over the 3040 because of its better matched turbine and compressor wheels.

Spot on mate.

The 3082 is a shitty combination (in my opinion anyway) - you're talking a 700 hp capable compressor matched with a rear only capable of 500hp (or less with the 0.63 rear which seems to be the common config on a 2L)

In my experience (and I've had quite a few friends run 3082s), the 3076 is capable of delivering the same peak horsepower on pump (the 3082 might have a slight edge when you wind a heap of boost into it, but at a guess the rear would still choke it) with better response.

Full boost at 4500rpm with a 3082 and a 0.82 rear on pump really suprises me.

[vertex_vr4]

Clutz,

It looks like 4300rpm is a point of interest on your dyno...

Did you have datalogger data for this run? What eng management stuff are you doing?

[Evo-00x]

Hey Steve, I'm gonna use a GT3040 on my car. If I'm not happy with the results I'll let you know about it and put something bigger on

[steve]

Cool man - I'll be interested to see how it goes.

I don't think they're a complete write off - I have seen some good results with them, just that they seem to be the exception rather than the rule. With the right engine combination, I'm sure they'll make the power - I just think there are better ways of going about it.

Just a thought on the 3076 - we're making 436hp atw through the 3076, and a conservative estimate would put that at about 500hp at the motor. The compressor is only rated to flow ~520hp, so it's entirely possible that we're pretty close to the limits of the turbo already. If you have plans to run big boost with good fuel, then something bigger along the lines of the 3082/3582 is definitely the go. We'll find out in a few months when we put a tank of c16 into my car, but we've got a feeling that the only gains we're going to find is from the extra timing we're able to wind in.

What rear are you going to go with?

[Evo-00x]

I'm running a HPC coated .82 rear on it and I could always just have the bigger GT35R turbine wheel put into it later as both turbos are identical otherwise Will see how it goes with the engine mods I've got first.

[Benny]

You get to the bottom of that turbo issue?

I know Paul was running 272's on the VR4 with the 20G at one point, not sure if it was with that TM chart though...

[LAN-EVO3]

sorry guys, just a newbie question....

would a 20g from GT pumps bolted to a ported evo 2 manifold to suit 20g be that much of a difference if the 20g was bolted to a GT pumps exhaust manifold?

thanks

mike