Loss Of Power On Track Day Skyline R33

[vladinator]

Hi Guys,

I am having an issue with my nissan skyline r33 gtst.

I went to track days few times now and I get loss of power after first 5 laps. Power decreases significantly. At wakefield I can reach 175km/h on straight but after about 5 laps I can reach only 150.

So thats 10-20% power loss.

I assume this is because car is getting too hot.

Mods r34 intercooler, 3'' exhaust turbo back, boost controller 10psi. fuel pump.

-So far I have changed to use different oil from motul 8100xcess (10-40) to castrol edge 10-60.

-I flushed the radiator and put better coolant. I have not flushed the coolant in engine, the damn release screw is ridiculous to get to and unscrew.

-changed AFM, and fuel pump. so def not those and oh boy it drinks alot.

Any recommendations??

[Plattsy]

could be time for a bigger intercooler...

also coil packs?

[vladinator]

i bought the car of friend and he had the coils replaced few yrs back, i have his reciept.

well it has bigger intercooler, but i didnt want get front mount and restrict the radiator.

i suppose i should turn boost down and see if i still get the problem.

[Plattsy]

i bought the car of friend and he had the coils replaced few yrs back, i have his reciept.

well it has bigger intercooler, but i didnt want get front mount and restrict the radiator.

i suppose i should turn boost down and see if i still get the problem.

dont worry about restricting the radiator.... you have no where near enough power to do that.

my theory is after a few laps of full throttle you ic is getting warm. maybe try a front mount.

depending on the coils he put in they could also be breaking down due to heat.... remove cover if you can to increase air flow.

also if you have apod filter put standard air box back in. same thing happens as with small ic, filter starts sucking in hot air from engine bay and you lose power.

[vladinator]

hey, thanks for advice.

i will lower boost to stock boost 6psi for next trackday, to see if it helps. That should show if intercooler is problem.

I removed cover for coils already.

the pod filter is just behind the light so that should get enough cold air in.

Do you think the old coolant in the engine could be the issue?

[Plattsy]

hey, thanks for advice.

i will lower boost to stock boost 6psi for next trackday, to see if it helps. That should show if intercooler is problem.

I removed cover for coils already.

the pod filter is just behind the light so that should get enough cold air in.

Do you think the old coolant in the engine could be the issue?

nah mate wont be coolant. unless engine is overheating...

that pod filter will not work.... unless you remove the light....

[gtr jet]

It would most definitely be the little side mount cooler as Paul causing your loss of power.

I remember my XR6 Turbo had the same issue with heat soak and the standard cooler.

As soon as I put a big front mount on it, problem solved.

[Plattsy]

keep boost as is and cooler the same.... try putting the original airbox back in with a clean filter...

if that doesnt bigger cooler is needed.

[vladinator]

dont have original airbox. i had airfilter recently cleaned and replaced AFM.

if the intercooler is the problem, shouldnt i see the difference if i lower the boost?

[gtr jet]

Lowering the boost will help but then you'll just have that same constant low power.

[Plattsy]

Lowering the boost will help but then you'll just have that same constant low power.

this.

honestly. buy a standard airbox. alot of guys with nearly 300kw still run them. search if you dont believe me...

[R32GOJIRA]

Or like mentioned before, remove headlight (easy enough to do in a couple of minutes at a track, a couple of plugs and some nuts), and put a headlight replacement air intake in place (just jap have them) and box off your pod filter. Induction cant get much colder than that.

[vladinator]

thanks for help guys, i will keep this in mind for next track day.

[Plattsy]

let us know how you get on.

[vladinator]

will do.

[boostn0199]

Definately heat soak issue the stock 33 34 coolers are rubbish espaiaclly if your pumping it around the track.

[mad082]

+1 for heat soak. The 34 cooler might be an ok upgrade for on the street, but they are rubbish for the track. Put it on a dyno and after a few runs power will start to drop substantially. That is where a fmic is an upgrade. It doesn't give you any more power, but it increases how long you have power.

[Kinks]

5 laps+ is pretty heavy on a stock car.

You'll run into intercooler heat soak, high oil temps, high water temps for starters.

Do 3 hard laps, 1 soft lap. Rinse, repeat. Your car will thank you.

[vladinator]

thanks for replies, yeah i will lower boost for next time and take light off see what happens.

yeah i fear i will need to upgrade to fmic, i didnt want to do that because on my other skyline after fmic installed i got bit of turbo lag.

[vladinator]

hey guys,

i found what the problem was, too high boost, through my intercooler

i went to trackday on friday @wakefield park , and i lowered the boost from 11psi to 6psi, and this solved the problem. I did 10 laps straight and had no issues with loss of power.

most of time now i do 5 laps, then 1 slow lap, then repeat.

i think r33 has dual stage boost, as it goes up 6psi, but after 4-5krpm it goes up to 10psi, but i didnt have any issues.

anyways thanks for help, and do try wakefield park on weekdays, it was open track all day not many cars at all.