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Rb26 expected power

dodo1410
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dodo1410 Apprentice

dodo1410

Posted
Posted

Hello again, I have a 1991 r32 gtr that I’ve modified and dynod. The power it gave me was a bit disappointing with 533 wheel horsepower and 444nm torque on a dyno jet dyno. On a heavier dyno it would read to about 433 wheel horsepower. I say disappointing because it currently has :

CP oversized 87mm pistons

Eagle H beam rods

Extended crank with the nitto collar 

stock oil pump (nitto on the way)

stock sump (leask sump on the way)

Garret G35-900 single turbo 

^ With 26psi of boost (1.6 bar)

6boost v band manifold 

turbosmart 60mm external wastegate

Brian crower 264 cams

tomei gaskets all around

arp head studs 

dual wallbro fuel pumps

dw 1050cc injectors

greddy radiator

metal Intercooler pipes

nismo thermostat 

offbrand fuel regulator (tomei regulator on the way)

ngk 7’s spark plugs (tuner refused to tune with 8’s for my car)

Running on a motec m800 

I know that running on e85 and opening the rpm to around 8500 instead of my current 7200 will also boost my power yet will it increase a lot or just slight because people like cardoGTR and andrew Hawkin from motive were all running around 600 wheel horsepower on the same setup as mine. Any feedback on what I’m missing?

 

thanks

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Kinkstaah Grand Master

Kinkstaah

Posted
Posted

I'd say post the dyno sheet so people can look on it, but you already know all dynos are different.

I mean 26psi on Petrol/Gasoline seems pretty up there, and if you aren't revving it out then unless your torque is really nosing over, then of course more RPM will equal more HP.

If you think E85 will make the difference between 533whp and 600whp the answer is absolutely yes. Given the only thing that makes power is the turbo, and you've got plenty of boost in there, it all seems semi reasonable to me. Curious to see what other people say though.

The one thing that never lies is MPH at the drag strip. See what you trap. (ok, it can lie a bit with altitude and conditions etc)

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Murray_Calavera Mentor

Murray_Calavera

Posted
Posted

Any chance you know how much timing your running to make that power?

Did your tuner say what the limitation was when they were tuning (eg knock? boost control issues? etc)

And final thought, if you are able to easily source e85 where you live, I'd 100% recommend using it. But before you go back for the flex tune, you probably want to get some bigger injectors. On e85 I see you maxing out those 1050cc injectors real quick. 

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TurboTapin Proficient

TurboTapin

Posted
Posted (edited)

As already mentioned, we need to know what was limiting you. Fuel? Knock? If I understood correctly, you have your rev limiter at 7200rpm?  If so, that is very low/strange, and your tuner would have made a point to discuss it. A G35-900 will continue to make power north of that.

What gas and where are you located? 

Edited by TurboTapin
  • Like 2
Dose Pipe Sutututu Grand Master

Dose Pipe Sutututu

Posted
Posted

I don't understand how a heavier dyno will make less power, but anyhow let's take your first figure. You're making 397kW on normal 98RON.

That's a pretty decent number, considering you'll be pretty knock limited with your fuel choice.

Throw in E85, more timing, more RPM and you'll go over 500kW with ease

  • Like 1
  • Thanks 1
GTSBoy Grand Master

GTSBoy

Posted
Posted
  On 22/04/2024 at 11:28 PM, Dose Pipe Sutututu said:

I don't understand how a heavier dyno will make less power

Expand  

I expect it's just slang from somewhere for a low reading dyno.

Probably originates in the US where the inertia dyno is king and some actually might be "heavier" than others.

Dose Pipe Sutututu Grand Master

Dose Pipe Sutututu

Posted
Posted
  On 23/04/2024 at 12:32 AM, GTSBoy said:

I expect it's just slang from somewhere for a low reading dyno.

Probably originates in the US where the inertia dyno is king and some actually might be "heavier" than others.

Expand  

what a load of street takeover baloney, of course it's some US jargon or bs. 

morboost Community Regular

morboost

Posted
Posted

what exhaust, intercooler, turbine housing?

I don't get this part ngk 7’s spark plugs (tuner refused to tune with 8’s for my car) why is the keyboard operator telling you what parts go in your car comes of as controlling, controls your engine, your tune, your horsepower.

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dodo1410 Apprentice

dodo1410

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  • Author
Posted
  On 22/04/2024 at 4:05 PM, TurboTapin said:

As already mentioned, we need to know what was limiting you. Fuel? Knock? If I understood correctly, you have your rev limiter at 7200rpm?  If so, that is very low/strange, and your tuner would have made a point to discuss it. A G35-900 will continue to make power north of that.

What gas and where are you located? 

Expand  

He limited my rpm because of some ptsd he had from a previous rb26 getting head starvation, and I’m located in Dubai using pump gas. We made more power running a bit more lean but for some reason my car did not like being that lean

dodo1410 Apprentice

dodo1410

Posted
  • Author
Posted
  On 23/04/2024 at 11:55 AM, morboost said:

what exhaust, intercooler, turbine housing?

I don't get this part ngk 7’s spark plugs (tuner refused to tune with 8’s for my car) why is the keyboard operator telling you what parts go in your car comes of as controlling, controls your engine, your tune, your horsepower.

Expand  

Stock intercooler and 0.83 housing, everybody I know with a gtr and running north of 20 psi has 8’s for plugs and for some reason my tuner refused to tune my car if I went to 8’s and said he’s not responsible for any damages that’ll happen. That freaked me out a bit and made me stay on my 7’s.

dodo1410 Apprentice

dodo1410

Posted
  • Author
Posted
  On 23/04/2024 at 12:36 AM, Dose Pipe Sutututu said:

what a load of street takeover baloney, of course it's some US jargon or bs. 

Expand  

yeah your correct i meant it as a low reading dyno and not a “heavy dyno” that’s just the slang people said to me so I repeated it here 

dodo1410 Apprentice

dodo1410

Posted
  • Author
Posted
  On 22/04/2024 at 2:17 PM, Murray_Calavera said:

Any chance you know how much timing your running to make that power?

Did your tuner say what the limitation was when they were tuning (eg knock? boost control issues? etc)

And final thought, if you are able to easily source e85 where you live, I'd 100% recommend using it. But before you go back for the flex tune, you probably want to get some bigger injectors. On e85 I see you maxing out those 1050cc injectors real quick. 

Expand  

My tuner said my timing is 12 on one bar of boost. 

dodo1410 Apprentice

dodo1410

Posted
  • Author
Posted
  On 22/04/2024 at 12:28 PM, Kinkstaah said:

I'd say post the dyno sheet so people can look on it, but you already know all dynos are different.

I mean 26psi on Petrol/Gasoline seems pretty up there, and if you aren't revving it out then unless your torque is really nosing over, then of course more RPM will equal more HP.

If you think E85 will make the difference between 533whp and 600whp the answer is absolutely yes. Given the only thing that makes power is the turbo, and you've got plenty of boost in there, it all seems semi reasonable to me. Curious to see what other people say though.

The one thing that never lies is MPH at the drag strip. See what you trap. (ok, it can lie a bit with altitude and conditions etc)

Expand  

I like the drag idea, and unfortunately I didn’t take a picture of the dyno sheet. I’ll try out my luck on the drag and see what I clock

TurboTapin Proficient

TurboTapin

Posted
Posted
  On 24/04/2024 at 4:19 PM, dodo1410 said:

He limited my rpm because of some ptsd he had from a previous rb26 getting head starvation, and I’m located in Dubai using pump gas. We made more power running a bit more lean but for some reason my car did not like being that lean

Expand  

Rb's have issues with bottom end starvation, not head starvation. Which either way, you probably wouldn't ever see on a dyno. Strange...

What's pump gas for you? Octane rating?

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