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Advice needed for RB25 mods and power levels.

Redknight
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Redknight Explorer

Redknight

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Posted (edited)

Advice needed for RB25 mods and power levels.

Hi guys! Hope all is well.

I just recently finished my project car. Its a R33 GTST with the following mods

- Hypergear At43 Turbo

- Refreshed top and bottom end

- 550CC injectors

- Walbro 460 fuel pump

- Link g4 ECU

- Greddy plenum

- Upgraded throttle body - 4"

- Blitz intercooler

- Straight through 4inch exhaust 

- Turbosmart internal wastegate 

- HKS pod filter

- Bigger cams

 

Now I was wanting to ask, is it worth tuning with E85 with the current 550cc injectors? or would 98 be better suited? Also what is a reliable power level I should be aiming for with the following mods?

thanks in advance!

Edited by Redknight
GTSBoy Grand Master

GTSBoy

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You didn't specify which ATR43 turbo.  they are variously able to do up to 600HP (engine).  550cc injectors are able to support around 550HP on 98 (give or take).  So there is a reasonable match between your injectors and the likely size of your turbo.  You will not be able to run E85 unless you restrict yourself to the ~400HP territory of the ATR43G1, because they won't have the flow needed.

My thoughts?  If you want to play with E85 then f**k off those 550s and put in some 1000cc EV14 based injectors.  It will cost you a little to do, but then the injectors will not be a problem.  if you don't want to play with E85, then just keep them, even though they are likely to be old shitty tech and EV14s will shit all over them from a great height.

As to the power limits.....Most of the mods you have made make no difference.  TB, plenum etc are all of no use at these power levels.  You will be able to make as much power as the turbo can support.  The limits will be imposed by the turbo, the injectors, the health of the ignition coils.  You can make 300rwkW on an unopened RB25 easily enough, plenty on here have done so.  That's up in the same territory as the turbo and the injectors.

Sensible part of the refresh you did on the motor would have to have been a decent head gasket?  And you really should have put ARP head studs in too.  If you haven't, you still can.

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baron_von_bootsector Enthusiast

baron_von_bootsector

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I would likely stick to 98 if you are planning on keeping those injectors but injectors are relatively cheap to replace and will hold back your setup depending on how hard you plan to push your setup. E85 will help you make more power if you are hitting a wall in terms of detonation but will require ~30% more injector at the same power level compared to 98.

No idea what kind of power you should be aiming for as it depends entirely on how much boost / revs you (and your tuner) are wiling to subject the refreshed bottom end to but 300KW+ seems to be an easily achievable number on a stock bottom end for a 25.

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vxsr33 Proficient

vxsr33

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Posted

You've already done a fair amount, might as well go a bit further and get some good 1000cc injectors as GTSBoy said so you can run E85.
I have an xpurt 1000cc top feed conversion kit on my r33gtst. idles perfect no issues at all, no different to stock injectors.

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Redknight Explorer

Redknight

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Hey guys! Sorry for the late reply. I'm a security guard so I work long hours :(

Thanks for the great advice! I can't remember exactly the name of the hypergear turbo but its rated at 500hp. I'll take everyone's advice and just tune for 98 for the time being and later down the track ill upgrade the injectors and go E85.

I'm getting the tune done on saturday at Lismore. Ill keep you guys posted with dyno sheets and numbers, because everyone loves that :D

Redknight Explorer

Redknight

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Posted (edited)

Hey guys

just got back from the dyno!

we made 280kw at the wheels at 17psi boost. Hits full boost by 3900 rpm and 700nm of torque. 

will post the dyno sheet soon for you guys to check out. Believe me, 280kw is more than enough on the streets for me. Boosting in second gear feels like fricken warp speed. Its insane how quick the car is.

 

Edited by Redknight
Redknight Explorer

Redknight

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posting the dyno sheet as soon as I get home. Sorry I'm late guys. Car had to be put back on dyno and tweaked because my stupid turbo manifold studs were loose and caused a leak. ( btw this is happening way too often, even with a metal gasket.

we settled on 272kw at wheels. Posting dyno sheet in a bit.

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