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Discussion Starter #1
hi guys, i wonder if anyone can help me, i have an r32 gtr running nearly 600bhp with hks 2530s and step 2 cams but doesnt hit ful boost till after 5000rpm, is that normal?
I took the car to rb motorsport and was informed that one of the turbo's was at fault, £1000 later its still the same, iv been told it could be the cam timing or boost controller.
Does anyone know somewhere around yorkshire that can remap it and diagnose this problem properly?
thanks
 

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i know it sounds stupid, but do you have an intercooler leak somewhere ?

Does it idle ok ?

Do you have a leaking gasket / intake or exhaust as it could make the turbos have to work harder to get to pressure in all the circumstances above.
 

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Discussion Starter #3
I have considered that but i have checked the intercooler and pipework and found no leaks, i havent checked the inlet gaskets though and buy the look of them they arent steel gaskets, are steel gaskets essential for this sort of power? they are fairly new but arent steel.
It holds boost nicely at 1.5 bar.
 

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RB should be able to sort that out easily and if you looking for someone to map the car then they will be your man too.
 

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what's your target boost? I don't hit mine until around 5000rpm either....but my boost is 1.9 bars. I'm well past 1 bar at 4000rpm, so what boost you are talking about can matter.

I don't know if you're a regular guy or a professional driver, but how aggressively you drive the car also makes a difference. When I have the mindset like I am trying my best to destroy my engine, I am always around 1.5~1.9 bars and the car is madness.

Ok, those things aside, I've had slow boost problems before. Check your wastegates. Check your boost controller hoses - boost control hoses can get complicated, and a pinhole in one can make a huge difference. It takes a bit of patience and sorting, but be persistent, and you'll get to the problem.

And what boost controller are you using? Did you try to fiddle with the settings? The gain setting makes a very big difference in how fast a turbo spools. Assuming the wastegate to boost solenoid hoses are all 100%. And that the solenoid itself is ok. When I had slow boost, I bought two spare boost solenoids (one Apexi replacement, one mechanical). Turned out to be a hole in a vacuum hose (which intuitively should cause over, not underboosting)...but replaced the hose, checked the connections for leaks, and I had my boost back.

Another possibility is leaking BOVs. Do you have an onboard wideband? If you're running very rich while spooling your turbos, there's an air leak - either intercooler pipe or BOV leak.

Finally, if the car has always been this way, it could be the map. Ignition mapping in what I like to call the "spool corridor" on an ignition map, can make night and day difference in turbo spoolup. If your map is sluggish and conservative, not getting anything decent until 5000rpm is quite possible. My map starts getting aggressive with ignition timing at 2800rpm and the hot timing runs diagonal along the boost corridor until 5500rpm, where I have to retard timing because I've got full-on boost by that point.

Have someone look at your map as well, and check the CAS setting. You could take the best-tuned car, walk over with just a screwdriver, loosen the three screws and turn that thing, tighten it, and you've just, in 30 seconds, sucked a hundred horsepower and all the life out of a car.
 

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Discussion Starter #7
spool

Thanks for your help guys, i'll have another look and eliminate some more possibilities and get back to you.
cheers
 

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In 4th gear i hit 1.5bar (my max boost) at 4.700rpm. My 2530 hold this pressure from 4.700 to 8.200 rpm. Tomei 270/10.25 cams and HKS strenght actuators.
 

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Discussion Starter #10
Maybe im asking for to much then, sounds like its fairly normal.
My next question is, what can i do to improve spool up time without changing my turbo's?
 

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A more aggressive map or push your turbos harder with more gain in the boost controller. I checked my boost last night and found that with hard driving, according to my datalog I was hitting 1.87 bars by 4600rpm. Basically, keeping the car between 5000-8000rpm yielded the goods, but it's so much power, like an on-off switch, that's not particularly safe around other cars.

Considering how hard the car has to be pushed to be in the power zone, and if the lag is hurting you, you might consider switching to N1 turbos. 450bhp may not sound like much in a Skyline, but the power is more flexible and available earlier and easier.
 

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have your cams been dialed in with exact setting?
that will effect your spool time
im running a t51r racing turbo which comes on boost @3750rpm and full boost just under 5000rpm (1.95bar) car producing [email protected] all 4 wheels tomei 260in 260ex 9.15 lift but apparently cams not been dialed in so my tuner is dialing em in and going for a remap his certain i should have better spool up time and a quicker motor with bigger numbers :) il keep you guys posted
 

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Discussion Starter #14
Thanks allot guys, looks like its going for a remap.
One more thing, how stupid would it be to swap one of my 2530 turbos for a 2540?
does anyone have experience running different sized turbos?
thanks again.
 

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Thanks allot guys, looks like its going for a remap.
One more thing, how stupid would it be to swap one of my 2530 turbos for a 2540?
does anyone have experience running different sized turbos?
thanks again.
In a Word NOOOOOOOO!

There would be more problems than I can think of....But Compessor Surge would be kronic!
 

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2540 = no power gain, more lag. There's a reason why no one runs them.
 

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i have the same 2530's and they come on hard around 4500- 5000 then all hell breaks loose and the car goes sideways ...:thumbsup: so i think yours are normal ..
 

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Maybe im asking for to much then, sounds like its fairly normal.
My next question is, what can i do to improve spool up time without changing my turbo's?
yes a remap focusing on your adjustable cam pulleys if you have them..u can set them for more power/more lag or more responce and less power.(iv gone for a balance of both)Also on the dyno get the percentage gain settings on the boost controller set as best u can in terms of responce..this makes a huge difference in terms of spool..

steer clear of 2540s there dogs..if u really want more power stick on -10s/2871r's/gt-rs's..however you will probably regret that too..they will be alot later coming on compared to your 2530s..

for the record i think full boost by 5k with these turbos is rather if not very late.I have 1.4kgs by under 4k with my -5s..

take it back to RB.if theres any man in the uk that can sort it..its Rod Bell.
 

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2530`s

Full boost around 5k is normal. My 2530s start spoolin at 4k and full boost by 5k.

You ve just spent a grand diagnosing it so why spend more ?!

Regards

Pete
 
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