My New Setup Feel Slower Than My Old Setup!

[Turbz RB-25]

Hi Fellas,

Some of you may know, I recently got my new setup, it is as follows:

1) RB25/30 Engine

2) GT35R 0.82 A/R Turbo

3) PLazmaman plennum

4) Nismo Injectors

5) GReddy FMIC

6) Nismo 555cc injectors

7) Bosch 040 Fuel Pump

8) 3.5" straight through exhaust

9) Tial 38mm external wastegate

10) Power FC

+ All the other usual smaller mods.

My old setup was just the standard RB25 engine, with the HKS GT2835 Pro S Kit 0.68 A/R, and I had all the other mods, apart from the RB30, the GT35R, and the external gate.

My Power with my new setup is 312 rwkw @ 16PSI

The power with my old setup was 272 rwkw @21 PSI

I took my brother for a drive today, and he agreed with me the car feels much slower than it used to. He said with the old setup, it felt like it was going "warp Speed" haha, but with this new setup, the drive just feels boring.... As you can imagine, I spent over $20,000, so his statement cut me pretty deep.

Anyway, once I wind up the boost to about 24 PSI on this setup to acheive a result of around 370 rwkw, do you think that rush feeling will come back?

I am pretty cut and need some advice.

I took the liberty of plotting the curve in an excel spread sheet.

The Yellow line "my GT35R" is my current setup.

The red line is my old GT2835 setup.

The blue line is this other fellas setup with simular mods to me.

As you can see, the new setup pretty much follows the exact line as my old 2835 setup at the start, and the overtakes it, so I don't understand how it can feel slower??

It's not just me, I've taken a few people for a drive in this past week and they've said the same thing.... it's cutting me up...

ANyway, any help would be appreciated.

Cheers.

[allthewaytotheskyline]

do you have a graph of your torque?

[SilverCal]

What cams and exhaust manifold do you have?

[Cjmartz2k]

Not saying it's the problem, but I think your injectors are too small for that turbo.

[WYTSKY]

mmm... there may not be anything wrong, but yeh, torque to me is more important then kw...

torque is that smack bang feeling that pulls you back into the seat when u hit boost... thats what we all like...

it may have been that the other one produced more, or more likely, it all came on in one big hit, where as this one is more gradual...

apart from some tuning, I dont know what u can do to change that?

[Turbz RB-25]

The tunner only provided me with the power curve, nothing else......

The cams I got are Tomei 256 inlet and HKS 264 Exhaust, with adjustable cam gears.

I didn't have the cams in my old 2835 setup, which makes it even more bizzare.......

[JiN_MaN]

Traction?

Also agreed 555 injectors arent huge for 310rwkw setup, Happen to know the injector duty cycle? I would assume your tuner would have told you if he thought it was a problem anyway.

Edited May 16, 2009 by JiN_MaN

[PM-R33]

As said, it might just must feel more progressive on the street than more of a rush if the old setup was like that....

[Turbz RB-25]

Yeah I know the injectors are getting boarder line. Injector duty cycle is 81% on 312 rwkw, so it's still ok.

Both setups didn't spin in 3rd gear, which is how I am testing/comparing.

ahhhhh the fun and games of upgrades hey fellas......

[R31 POWER]

As said, it might just must feel more progressive on the street than more of a rush if the old setup was like that....

I agree. It's probalay not ''hitting'' as hard but still fast.

[OVADRV]

I agree with WYTSKY more gradual power

[SilverCal]

I had an rb25/30 in my vl with tomei poncams and gt35/40 with a 1.06 rear with microtech 600cc injectors, ETM manifold and it made 340rwkw, and it was awesome put ur foot into it in second and it would turn the tyres straight away, id say it was making fullboost by about 3500rpm (18psi) compared to when i had the excat same setup on the 25 bottom end it came on full boost at about 4500rpm!

Looking at your graph it looks very lazy in making power, i dunno what the cause of that is but yeah it looks very slow in making power..

[simpletool]

You don't need a torque curve when you've got a power curve - torque is related to power (just power/revs). If it makes the same power at same revs then it's making the same torque.

IF it is indeed making those numbers and it seems LESS linear if anything then perhaps it's all in your head. Are you prompting people to say it feels slower?

[VB-]

wont be the curve, look at the graph. it goes from making less torque, to making more torque across the midle of the rev range, ie, its coming on harder

your imagining it. or something has gone wrong between it being dyno'd and you picking it up. i'm betting its the first one

maybe you had all these ideas about what a RB30DET+GT35 'should' be like and thats thrown out your perception

[paulr33]

check the basics

base timing at idle, state of tune, AFRs, check it on a dyno etc

could be a few hundred things wrong

[gfunkk]

i cant believe 312kw got referred to as "boring"

[SATO GTS]

take it to the race track and find out if its quicker

laggy turbos always feel faster

in reality they arnt

[rob82]

Not saying it's the problem, but I think your injectors are too small for that turbo.

I've made around 250awkw on EVO9 and EVO10's with 550cc Inj so another two injectors = (250/4)*6 = 375awkw. Thats dyno dynamics figures.

So 550cc injectors are well within the scope of that turbo on std pump density fuel as long as your fuel pump setup is up to it.

I went from a std Rb26 to a RB30DETT with -5 turbos and on same boost as before I would say the RB26 felt more exciting to drive but you compare the actual accelleration rates and you'll find its a completely different story. I'm seeing 80-160km/hr times on a 4th gear roll on of about 5.4-5.6 sec on 12psi of boost before it was about 7 secs.

I can tell you that even on that boost I can get roll on wheelspin in 3rd.

[joeyjoejoejuniorshabadoo]

Traction?

Also agreed 555 injectors arent huge for 310rwkw setup, Happen to know the injector duty cycle? I would assume your tuner would have told you if he thought it was a problem anyway.

for 310 pulp 555's are fine... for 370 that's another story...

[Taso84]

Yep, id say its the laggy turbo syndrome.

LAggy turbos that come on really hard will always feel faster since it pulls more G's, but overall it wont be faster on the tarmac.

I've been in 2 similar powered cars, a 240rwkw 33 and a 250rwkw one. Shouldn't feel very different right? wrong! The 250rwkw has nothing under 4 Grand so when the turbo does come on, the G force is way more than what u feeel on the 240rwkw one.

Depends what you like overall, me personally, i prefer more midrange and gradual build up of power as that is always going to be quicker