Big turbo, stock cooler... help!

[RHiSC]

A mate of mine got a 2540 turbo put on his RB25DET Skyline, but is still using the stock cooler. His car is running excessivly rich, and will start to miss as soon as he comes on boost. Basically the car is undrivable in this condition... it also stalls as soon as he put the clutch all the way in for more than a fwe seconds (eg, coming to a stop).

Could this have something to do the the stock cooler he is still using? the 2540's actuator has a 1 bar base pressure, and the turbo is having trouble making more than 0.5 bar of boost - with heavy missing and backfiring.

[Jay95R33]

OMG !!!

A 2540 at 1 bar with the stock cooler !!

Sorry, just a bit shocked...

It could be a few things.

The stalling thing is usually due to a BOV venting out into the air, does he have one of these?

The misfiring could be something as simple as the spark plugs still having the factory gapping on them. Whip them out and reduce the gap down to 0.8 - 0.7mm.

He should really reduce the boost down to .5 bar until he get's it run up on a dyno and get's a cooler to match the flow of the turbo. But this is a bit hard when you've got a actuator set at 1 bar

I presume he is still running the stock ECU? If he is, I dare say the stock ECu is having a heart attack trying to figure out the new turbo.

J

[enilyks33r]

Have you checked the ignition? It sounds like it missing.

The stalling may be BOV related if you are venting to atmo rather than recirc.

[RHiSC]

Yeah he's getting a GTR cooler installed today... so that should flow a lot better. He has a stock ECU which can be remapped... but it hasn't been remapped or anything yet.

Yeah i know about the rev drop with the BOV... but it shouldnt be this bad... it stalls even when you dont go on boost, just when you stop suddenly.

[Jay95R33]

So are you saying that he does have a BOV that vents into the air?

Remember that the 2540 will flow more air, and even when your off boost the wheels are still spinning.

So if the after market BOV is set wrong, you get air comming back out the AFM, or out the BOV which will = stall.

The GTR cooler should be a good match with the 2540.

Let hope he's fuel system will keep up.

J

[RHiSC]

yeah, 550 injectors, and a bosch 040 fuel pump... today he is also dumping the blitz bov, for the hks ssqv... so it should be all good once its tuned properly.

[Sydneykid]

HI RHiSC, the standard RB25DET injectors are rated at 370 cc, which is good for close to 400 bhp. You won't get one 2540 anywhere near that power output. Save the money, doesn't need injectors. The R33 GTR intercoolor is good for 300 rwkw, also way beyond the 2540, so OK there. The Bosch 040 fuel pump is good for 235 litres per hour which = around 520 bhp, so it will do the job just fine.

Hope that helps

[macka]

Who do u know that can remap r33s?

I dont know anyone in aust who can do this yet..

[Jay95R33]

Originally posted by macka

Who do u know that can remap r33s?

I dont know anyone in aust who can do this yet..

Macka - I stumbled across this the other day;

http://www.xtremecarperformance.com.au/

Don't know how good, or even how much it is.

I've got a funny feeling that they use a R32 ECU with a PIC chip for the VCT and re-tune it for a R33.

I've got a R32 ECU still sitting here that I might 'one day' get re-tuned for a R33..........

J

[Sydneykid]

Hi Macka, me either, so we use Power FC's on R33 GTST's.

[Jay95R33]

Yeah, you can't go past the PFC. Anyone want to donate one

[Al]

Just a logical thought from a "none expert".

If the engine has 550cc injectors and running the factory ECU, wouldn't the ecu be flooding the engine? As the 550cc inj. can flow more fuel than the 370cc.

For this set-up you must really run an aftermarket ecu as it would operate alot smoother and unlock ALOT more power from the engine.

Just my 2c.

[macka]

Gday Fellas

Jay I had a qhuick squizz it doesnt say much about the r33s in fact half the site was down when i looked?? I had a tip secret tuned rom in mine it consisted of no daughter board but a reprogrammed EEPROM which is electrically eraseable unlike the roms with the windows (uv eraseable) which is what is normally used. So maybe your right

Im with you sydneykid, altho the wolf4d plug and play looks good too

If you use bigger squirters your engine will run rich across the board Al yeah..will need a whole retune

[KamikazeR33]

umm could it have something to do wif the r33 afm not being able to compute the bigger airflow running though?

so get a z32 afm

[Sydneykid]

Hi KamikazeR33, the standard R33 RB25DET AFM seems to have good enough resolution at 40 lbs of air per minute (enough for 400 bhp), which is more than the 2540 can supply. So I doubt it is an AFM problem, unless it is faulty.

Hope that helps some more

[Al]

Originally posted by macka

Gday Fellas

Im with you sydneykid, altho the wolf4d plug and play looks good too

If you use bigger squirters your engine will run rich across the board Al yeah..will need a whole retune

I have install the wolf 3d "plug-in/plug and play" in my car, while running the stock turbo. I felt this was the better order to complete mods with. I notice a big up in performance, especially in the low to mid range.

VERY PLEASED WITH THE ECU :uh-huh:

[rev210]

before going out and buying intercoolers and things. Why doesn't he fix the problem? He would do better with an appropriate sized frount mounted intercooler tho.

It's quite obviously a tuning issue. Fix this first, then start upgrades.

[macka]

Originally posted by Al

I have install the wolf 3d "plug-in/plug and play" in my car, while running the stock turbo.  I felt this was the better order to complete mods with.  I notice a big up in performance, especially in the low to mid range.

VERY PLEASED WITH THE ECU :uh-huh:

Will PM u about dat wolf big AL

[adam 32]

careful with big injectors and std ECU. a mate of mine but rx7 injectors into his RB20 and they sprayed so much fuel it coated the bores and the bottom end needed rebuilding

[Al]

Glad to see that my logical thinking was correct. (Glad for myself, but feel sorry for the person in question)

With any mods, you should always sit down and think what your long term goal is, and then persue it, in a researched manner, by setting up all the support systems first.

my 2c worth.

Alan