Rb20det dissappointing dyno results

[legend01]

Hi Guys

Rebuilt turbo on second dyno run much better though the tuner is still not happy with it says exhaust to quite to restrictive (but it nice and quite) beleives injectors are the wrong type (hi flow rotary idle problems) and to small and running to hot so tuning was stopped till problems rectified but still pretty good result will post dybo graphs of low and high boost for opions

thanks Peter

Hi Guys

Been rebuilding my car from the ground up for the last 18 months finally got to the stage of dyno tuning today with dissappointing results I like some oppionions from people with a bit more experence than Ive got on these matters

as to why you think its not making much power at the moment the tuners have given mr there ideas but would like some more ,I'll list the mods and the graph and like to hear all idea's

1. 600x300x76 fmic

2.Hks cast exhaust manifold

3.Hks 35mm external waste gate

4.Hks t04 with .4 exhaust housing

5.Hks adjustable cam gears set a standard for now

6.Hks 264 inlet and exhaust cams 9mm lift

7.Hks air filter in standard air box with cold air induction

8.Head ported and polished

9. inlet plenum runners honed smooth

10.460 high flowed injectors

11.Gfb stealth fx plumbed back into inlet system

12. Malpassi rising rate fuel pressure regulator

13 gtr fuel pump

14.full 3" exhaust system from turbo back waste gate plumbed back into exhaust just b4 high flow cat

15. Wolf 3d ver 4 plug in with boost control and thurmo fan control

Thats all i can think of off the top of my head that has to do with engine mods bottom end standard but has only 60400klm's on it still hone marks in the bore

just like to hear from you guys now on your verdicts on the problem just gotta try and post the dyno graph now.

[Cubes]

More importantly... How does it feel to drive?

Does it feel like its a little down on power compared to the reading? Something I guess one would only know from experience.

[legend01]

It was a stock auto when I bought it so it should be no comparrison

Cheers Peter

[jazza08]

Im guessin thats 250ish rwkw?

If so thats not a bad result...

If thats 150ish rwkw its a very bad result and i have no clue why lol

[legend01]

Bad result its only 160 rwkw

[Sydneykid]

Hi Guys        Been rebuilding my car from the ground up for the last 18 months finally got to the stage of dyno tuning today with dissappointing results I like some oppionions from people with a bit more experence than Ive got on these matters  

as to why you think its not making much power at the moment the tuners have given mr there ideas but would like some more ,I'll list the mods and the graph and like to hear all idea's  

1. 600x300x76 fmic

2.Hks cast exhaust manifold

3.Hks 35mm external waste gate

4.Hks t04 with .4 exhaust housing

5.Hks  adjustable cam gears set a standard for now

6.Hks 264 inlet and exhaust cams 9mm lift

7.Hks air filter in standard air box with cold air induction

8.Head ported and polished

9. inlet plenum runners honed smooth

10.460 high flowed injectors

11.Gfb stealth fx plumbed back into inlet system

12. Malpassi rising rate fuel pressure regulator

13 gtr fuel pump

14.full 3" exhaust system from turbo back waste gate plumbed back into exhaust just b4 high flow cat

15. Wolf 3d ver 4 plug in with boost control and thurmo fan control

Thats all i can think of off the top of my head that has to do with engine mods bottom end standard but has only 60400klm's on it still hone marks in the bore

just like to hear from you guys now on your verdicts on the problem just gotta try and post the dyno graph now.

Hi, Legend01, 160 rwkw is a bit low for the mods, depends on the boost of course, I would be looking for 220+ rwkw so there is a fair bit to go. Do you have the graphs of the boost curve and the A/F ratios?

There are couple of simple things I do when I get a lower than expected result on the dyno. First I remove the airfilter, just run the AFM open and see what difference that makes. Then I drop the exhaust, from just in front of the cat, that will tell you if you have a problem there. These are both done on the dyno as they only take a few minutes to test.

If they both show nothing drastic, then I like to know what sort of restriction the intercooler has. So I compare it, out of the turbo and at the plenum, obviously i don't have to do that on the dyno. If it shows no real restriction then everything else is down to tuning, A/F ratios, boost, ignition timing and cam timing.

Hope that helps:cheers:

[legend01]

Sorry i dont have those graphs but that was running 18psi there but from 12 to 18 boost kept droping of around the same -place and going back down to 8psi within 500-rpm depending on what boost we were puting into it

Thanks Peter

[SXC180]

hey Ive got rb20det and i pumped out 254rwkw on 19 psi and i dont have my head done and ive still got standard cams .... i think there is something wrong with your car what size rear housing is on the turbo you said .4 but it must be .63 prob ?

[Turbine]

Hi legend01, this may be a silly comment but if this car is an auto could it be slipping at all?

If so that could be worth a look. Have a look for boost leaks in the system as well.

Turbine

[legend01]

Hi guys

SXC180 it is a .48 when the turbo was rebuilt at Dyna torque paul there said he had never seen one that small but with as large an impeller blade

Turbine

It was an auto it now has an exceedy 450 hp clutch in it and an R33 gearbox

Cheers Peter

[MerlinTheHapyPig]

what cooler is it? that's where i'd start looking

[legend01]

Hybrid 600x300x76 we tested that was flowing free

Peter

[R32-GTS]

could also be retarded cam timing ? Who set it up. Just double check it.

[legend01]

I set it up myself, did have it retarded but the tuner asked for it to be set back to standard as a starting post

Cheers Peter

[R32-GTS]

Ive had this problem with my old rb20 when i put a fresh motor in it. Set the base timing up to 15degrees and it made about 150rwhp. Very weak. I then moved the crank angle sensor to where it used to sit just passed the half way mark between the top right 10mm bolt and it made 220rwhp .

[MerlinTheHapyPig]

Hybrid 600x300x76 we tested that was flowing free

                                                                                  Peter

hmm, is it one of the hybrid copies floating around?

they tend to be very free flowing yes, but they don't actually cool well.

maybe have a look at intake temps

[Chris32]

I had a similar problem after my PFC/injectors went in, didn't matter what boost, it made 160rwkw

Turned out to be a leaking intercooler hose, tightened it up, made another 40rwkw

Check them all, as well as idle vacuum

Chris

[1400r]

wild guess your turbo's surging as the rear wheel is to small this would account for the change in boost. Put the standard turbo back on and see if it hold boost any better it will probably end up making the same sort of power.

[CerealKiller]

RB20DET...that's your problem

no but seriously, what AFR is it running? Could be that. My feeling is that the cam timing or the tuning is off. Just for reference I currently make 150rwkw with:

Blitz LM FMIC

3" turbo back w/ high flow cat

stock air box

stock turbo (12psi)

stock internals

A'PEXi S-AFC2

[TTT]

Doesn't a stock R33 turbo have a 0.43 rear?

That turbo you have don't sound right at all.

and you said it gets to 18 psi then drops back to 9..

isn't that what happens when the revs catch up with the psi on a restrictive turbo?

reminds me of my MX6 I used to have.