Drag Rb25Det, Fuel ?

[BloodBath]

What sare some of the fastest stock turbo RB25's that you all have seen out there??

How much timing can I add at full boost when going from 91 oct to vp 116???

I'm shooting for a mid 12 on 12 psi, stock turbo.

[r32-25t]

Why are you putting 91 in it at anytime?

[GTScotT]

You are dicking yourself in terms of performance and reliability.

Save your money and highflow the stock turbo to run the 12 instead of running dual maps so you can run some magical sauce only to blow the rear wheel off the turbo which might take your motor with it.

[2.5L]

Why are you putting 91 in it at anytime?

This... a million times this.

[StevenCJR31]

about the only skyline on this forum running 91 is a RB30e engined R31!

[BloodBath]

91 is premium pump gas in az. Thats just the way it is.

at 12 psi I have 17 degrees I believe.

[JKR-32]

I would hazard a guess that he is in America, as they seem to have shit fuels + his car is listed as a 240sx

[BloodBath]

Yes I am in Arizona. I would kill for a Skyline, but no one around has the know how to imports them and make them street legal easily.

[Beer Baron]

plus guys before you get all excited US fuel octane number is measured differently to ours (they quote an average of RON and MON we just quote RON which reads much higher than MON ratings). their 91 octane (AKI) fuel is somewhere around our 95RON fuel (not quite as good as our 98 RON but nor far off).

as for the OP, there is no set formula. you need to tune it for the new fuel and see how much boost and timing it will take before it either stops making more power or it knocks.

also why only 12psi? with no more boost you will struggle to get much more power. if it's only for drag runs, wind it up a bit. even just another 3psi of so will give some decent gain.

[BloodBath]

I've read that 12 psi is the most you want to run on the stock, ceramic turbo wheel. just not looking to hurt the engine. I need that bottom end to hold up to the GT35 when funding is available.

So far my best is a 13.30 @107. 12 psi 11.8ish afr's. this is with a 2.0 60'. I have some mickey thompson et streets now. shooting for a high 12's, maybe mid 12's on race gas.

[BloodBath]

ive also read some tech articles about an sr20det that with just changing the fuel and timing, maybe a different plug too. picked up 40 hp, same boost level. I just need to do some tweaking.

[Lithium]

E85 could work quite well, fyi 98RON we get in NZ and Oz is equivalent to 89MON

[jjman]

wtf is MON?

[bored33]

MON is tested under load. Someone do correct me if I'm wrong.

[045HOW]

wtf is MON?

whatchatalkinboutMON?

are our fuel standards alright? or bad compared to some other countries?

[KiwiRS4T]

I've read that 12 psi is the most you want to run on the stock, ceramic turbo wheel. just not looking to hurt the engine. I need that bottom end to hold up to the GT35 when funding is available.

So far my best is a 13.30 @107. 12 psi 11.8ish afr's. this is with a 2.0 60'. I have some mickey thompson et streets now. shooting for a high 12's, maybe mid 12's on race gas.

If you are keeping the bottom end stock (i.e. not rebored and forged etc ) a GT3076 will give you all the power you can handle - 300 - 330kw. A GT35 is good for a lot more than the stock RB25 can cope with.

[StevenCJR31]

wtf is MON?

motor octane number??ha!

[JonnoHR31]

if you use e85 you could safely run more boost as the EGTs would be a lot lower, meaning a lot less stress on the turbine wheel.

[XRATED]

It's not the boost that kills the turbo, it's the excess shaft speed.

US fuel also contains more benzine and other products that make it more knock resistant for the same 'octane rating'.

Your going to need a fair bit more power to run consistant mid 12's from a 13... Id spend some time taking weight out of the thing first. Then a ethanol tune.

Or nitrous.

Cheers

Justin

[BloodBath]

I eventually plan on building up an engine for the car. the GT35 is just so I dont outgrow the turbo.

My car with me in it is under 3000 pounds, I should be able to shave a quarter second off the 60' foot time, I will be launching off of a two step at 5000. so a quarter second off the sixty has always been, and SHOULD be good for a half second off the big end. thats 12.80 without race gas.

I'm mainly just curious how much timing I can add for the race gas. Ive heard 6 degrees, 8 degrees??? also would I need to go to a hotter plug???