Changing to gt3071r

[Quattronaut]

You seem to have 6 gear :-)

Hard to say. Maybe your maximum torque would be at lower RPM with doing the dyno in 4th or even 5th gear, giving that whole thing more time to spool up. Also the Wagner evo COULD cost some rpm in spooling due to it's bigger diameter- some guys say that. On the other hand, this diameter, and the bigger exhaust compared to stock RS2, should improve power in upper rpm- I don't think this one is too small.

[Jamo]

the higher the gear the more the curve shifts right and lower to the left. End of the day dyno's are only a snapshot as long as it's performing on the road.

I'd take some logs and give them to EspenW to graph out

[quattro-nick]

normally you can achieve a 380hp max with a rs2 setup,no?
maybe with a bigger ic,injectors and exhaust(3")
i think the 325 hp is a little bit on the low side

[bartieke210]

I also expected a little more above the 5000rpm. But I just think about something. A few monds ago I had to change the fuel lines because they were crap and leaking. I used copper lines what they use for heat burners. The outside dimater was exactly the same, but the inner diameter was lightly smaller. I'm talking about 0,5-1mm max. Could this be the problem? That the fuel pressure drops when the fuel consumption is high. I'm gonna try to measure this pressure while driving.

[quattro-nick]

i dont think that your fuel lines will give problems bart

[bartieke210]

I was just thinking

[andy10v]

Is it a stock fuel pump? Is it relayed?

[bartieke210]

It"s a RS2 fuel pump. And what do you mean by "relayed"?

[andy10v]

Running a thicker wire to the fuel pump, switched by a relay, prevents voltage drop at the pump as that can cause the engine to run lean under high boost/high rpm.

Dave did a how to for the 100s4;

http://12v.org/urs/chassis_map/24327.phtml

[Quattronaut]

What I would do next is 2 things:
1. ask prj what power & torque is expected, at what rpms- and maybe something about the boost behaviour.
2. Buy and install a good boost gauge. Because with this you can take a look at how boost really behaves at upper rpm. AND- because it's a really cool item :-)

edit: Jap. Check fuel wiring, pump etc. first. But be sure to install boost gauge ;-)

[bartieke210]

I also should see this by measuring the fuel pressure under load. Worth a test

[Sonic]

I burnt out the wire going to the original pump when I pushed it as far as it would go. Get it relayed for sure if you want to run any serious power or aftermarket pump.

[FabS6]

going back to the turbochargers.... another option is the new family GTX... the GTX2860 or 71. If I am not wrong, it is used for rally cars so is capable of monstrous torque with K24 spool-up times. I just dislike laggy turbos...I have no time to take a cup of coffee during driving lol

I am not much into Garretts but this would definitely a good choice after changing the rods on my AAN, the GTX28xx.
Otherwise I would stuck with an RS2 turbocharger with just a little of work inside of it...like a port and polish of the compressor side and possibly turbine housing too, as I did on my stock unit.

[bartieke210]

Today I measured the fuel pressure. 3.6bar on idle (0.5bar vacuum) , 5.7-5.8 on full boost (1.7-1.8bar) and 5.2-5.3 at almost 7000rpm (boost drops to 1.4bar). Maybe a little too low in de high revs? Or is the difference not big enough? Have 4bar FPR btw. The 3 bar you see in the picture is after an half an hour standing stil.

I'm defenitly going to relay the fuel pump to be sure.

[Quattronaut]

Maybe your thinner fuel lines do not limit fuel pressure, but the amount of fuel passing it, so I would fix that, too.