411rwhp from stock internals

[Sydneykid]

Hi Roy, then you gained nothing (ie; reduced restriction from no AFM) by running MAP. All the disadvantages (of MAP) and no advantage, seems strange logic to me.

[Roy]

When i bought the car the previous owner had a silver top RB20 installed into the R31 GTSX.

It took many months of tuning to get the thing running nicely at light throttle, low rpm etc. It still had the AFM in place, and since it was the same diam as inlet piping and only added a couple of inches to inlet tract lenght i left it in place. I didnt believe it was posing a restriction.

If i had done all the mods on the car then i sure would not have used an MT-8. But using an aftermarket computer did give me some flexibility down the road with mods and a handy handset.

You say disavantages of MAP, whist im aware that every part on a road car is a compromise, doesnt the V6 Holden engine still use MAP sensing?

Now maybe not the latest and greatest but they still use it and get legal emissions and competitive fuel economy.

Not stating MAP is the way to go, just pointing out no part on a car isnt a flawed compromise of some sort.

[Sydneykid]

Please Roy, an engine designed in 1968 by Buick, with pushrods? I am not going there.......

[Roy]

lol... fair enough. What about 2JZ Toyota engines, they use MAP sensing std dont they?

[Sydneykid]

Hi Roy, and Toyota spent how many millions getting the tuning right? If you have that sort of budget you can get it right too.

[Roy]

I dont know how much they spent.

I suspect that it was no more expensive then the method Nissan use, or they would be doing it...wouldnt they, no organisation especially one as big as Toyota is going to throw away money.

Anyway... just trying to point out, that every process/system/part has its pros & cons, believers and detractors.

[rbs13]

it doesnt matter how much the factory tuned it.. as soon as you mod it the std tuning is not so good!.. it would alter the tuning.

[GTS-t VSPEC]

Sydneykid, My car is a daily driver and I haven't noticed any side effects of running the MAP sensor. I don't seem to have any issues with running lean on the road, and with stock pistons 400+rwhp I'd have probably found out by now:D

[Sydneykid]

So GTS-t VSPEC, do you run it at 17 psi and 411 rwhp all the time?

[GTS-t VSPEC]

I've run it for a few days now at 411rwhp, normal setup is 360rwhp, as I don't have sufficient funds to do the internals yet, which I fear have almost reached there limits:D

I tend to bounce off the limiter in 1st, 2nd and 3rd with the 411, so I need to invest in some serious rubber:D

[Sydneykid]

OK GTS-t VSPEC, 360 rwhp (270 rwkw or 420 bhp) that's OK, we do it all the time. Standard internals handle that power level, no problems. We have one that has been running 290 rwkw for almost 12 months, daily driver, 6 trips to the drags (did an 11.9) and 3 or 4 circuit days. It has an oil cooler though, which I don't think yours has.

Oh and tell Steve it runs a Power FC, sorry couldn't resist it.....

[GTS-t VSPEC]

I do plan on getting an oil cooler at some stage, along with many other things, but funds prohibit it all at the moment:( I'm hoping to run a low 12 soon, once the new diff is in.

With good tuning I think the RB25's are a strong engine, but a bad tuner can kill them at only 300rwhp or less.

[N I B]

Gary stewarts stock RB25 runs 400rwhp with 2 25/30s and a real bad ECU ( no name as i don't want some other group to start) and its a full time competitive race car on pump fuel with 2 1/2 seasons racing without fail so the RB25 is a tough sucker.

I have no problems with Power FCs and did not start this thread, i sell support and like Wolf ECUs and tune as many PFCs as anyone but don't like needless bagging of a good product so lets get along and enjoy a good Forum.

Steve.

[Steve]

Steve-SST, I must ask, but dont blame you if you dont want to reveal trade secrets, what AF ratios do you like to tune to with the stock bottom end? Also, how much timing would you recommend to pull for a safety margin when you start to see/hear detonation?

I have just put my car in to get cams, head gasket, trust plenum and bigger turbine AR (0.87) then it will be time for a tune. I am aiming around the 400rwhp mark.

Any advice would be greatly appreciated - I would like it to last as long as possible while I build a 3L bottom end.

I do realise that your experience is what you get paid for above and beyond normal labour rates (rightly so), so please feel free to tell to pull my head in if you dont want to answer such questions.

Cheers

[N I B]

Pauls GTS has 11-1 afr@10deg thru peak torque and 12-1@15 thru the top end to look after the stock parts but this will change after he gets his forged motor.His daily map is very different.

[Steve]

Thanks for that:)