That dyno you posted was in ShootOut mode, which estimates engine horsepower, not wheel horsepower.

434 "ShootOut HP" is closer to 360whp on a DD in non-ShootOut mode, give or take depending on conditions.

 

Ah yes, good observation. I was wondering how 98 RON (94 octane U.S.) could yield such a high result.

IF that estimation is correct (434whp in DD shootout mode ~= 360whp DJ), the result seems somewhat low for 24psi. Also, I would not expect high IAT to be an issue with a GT35R cruising along at 24 psi.

Advice - Run the dyno in normal mode and retry.

 

The fuel is pump gas - 98 octane, its the best you get over here in the UK at the gas station.


As you have noticed the dyno was in shootout mode; in the UK all the tuners run in this mode, as it allows a better comparison between other dyno dynamic rollers at other establishments. I carnt see though how running in normal mode would alter anything car wise. It would still be working the engine as hard, boosting the same etc. so surely the end result would be the same; high IT and mixture running rich?

My mapper seemed to think theres a restriction in the exhaust side of things, which is causing a build up of heat, possibly cams? I'm running the Piper BP300's which only have 265 duration (217 @ 1mm) and 11.5mm lift. Even so, they are better than the OEM ones so i figure it must be something else.

 

If he's trapping 121 mph in the 1/4 then it is making around 420 whp. A stocker on race gas has made around 400 whp, and they trap around 117 mph. These are close to stock weight cars as well.

 

Ok, 98 octane RON is about the equivalent of U.S. 93 octane pump premium (we measure ours differently). You're not going to be able to turn up the boost and get big power numbers with that fuel, period. Also, don't pay too much attention to claims of running greater boost on pump fuel - which does not necessarily lead to more power. Why? Because the ignition timing has to be retarded to withstand the high boost, which negates any potential power increase.

~420whp (Dynojet equivalent estimation) for a GT35R at 24psi is in the neighborhood of what's normal, but seems slightly on the low side. There are quite a few factors that affect this both directly and indirectly, but it's difficult to comment without knowing all the specifics of your setup.


I have an idea of what may be a contributing factor in your situation, but I have a few questions:

- What means of tuning are you using? You report running too rich, so what is the mixture (have a graph?), and what are you doing about it?

- What does your ignition table look like?

- You report high IAT. Have you checked your EGT?

- You should NOT have any surge issues. This is probably linked to your problem. Please furnish a boost graph (the one before you delayed the boost).

- Do you have those cams installed straight up - factory gears?

 

Hi Ted,

I spoke to my mapper earlier today ( he was in his car on his way to map another car; he travels the world mapping rally cars for a profession). I asked him the questions and these are basically the answers he gave :



Everyone is saying that this turbo should not surge, which lead me to think that maybe the turbo was faulty, but another source says that if the turbo was faulty then there would be no way that it would produce anywhere near 400bhp at the flywheel like it is doing. Have to say though, this turbo doesn't sound as smooth when i turn the engine off as my old ball bearing converted OEM turbo, though i put this down to the GT35R having more mass and twin bearings.

 

At a glance, it appears as though VE is rapidly decreasing above 6000rpm, which would account for the rich condition and may indirectly contribute to the high IAT. It may be due to something in the exhaust system that is restrictive, but there is no way to be certain.

The surging indicates that for whatever reason, the engine cannot mechanically accept enough air mass at that point. This is unusual for a GT35R, but with the shootout mode graph, I cannot really overlay your boost curve to mine to make a better determination.

We still don't know the actual cam timing - a few degrees 'this way and that' is sometimes significant.

 

I think your timing is pretty low too. retarded ignition and fat afr = high egts.

just because your car is running fat with ignition timing low doesn't mean its running safe.

At WOT my 35R's AIT only went 10-12 degrees higher than ambient going thru 1-4 gears.

 

Thanks for the feedback guys

My freind is having his Evo 9 mapped within the nxt couple of weeks; same everything apart from his is an Evo9 with the MIVEC. He's also using a different mapper.

I guess best bet now is to see how he gets on, and take it from there

 

Richi, any updates on your friends setup on the 9?