Rather Serious Detonation After 10mins Driving..

[bubba]

Where do I start?!

Car is an R32 GTSt, minimal engine mods: 3" catback and split dump (standard front pipe and cat. for some stupid reason), pod filter, profec b spec2, oil cooler (in front of radiator), fmic and gtr radiator (twice as thick as the one I had which I was told was a non turbo radiator!), stock ecu and timing was checked.

Has been a problem for a while now but what with breaking my gearbox it's been a while since I've put my foot down. Here's the situation:

Start car, let car warm up. Goes hard on stock boost and if I turn the controller up to 12-13psi, no problems. After about 10mins (sometimes sooner if I'm giving it a hard time) it will start to ping, mainly in first and second and mostly when I get on the gas hard. If I roll onto boost in 3rd on the highway it won't ping (that I can hear anyway).

It is noticeably worse when using the ebc to run stock boost but holding the wastegate closed till 9psi than running with the boost controller off.

With the ebc on, it is so bad it almost sounds like a squealing noise (hence I thought it could have been the new clutch) down low then slows down to an audible pinging noise towards the higher revs (not that I ever let it get that far after I realised it was pinging!)

The obvious first step is to properly shield the pod, but can it really cause this sort of detonation?

The next time I think would be relocate (or remove) the oil cooler to somewhere other than in front of the radiator.. temp needle sits between 1/2 and 2/3 so I put a gtr radiator in that was thicker and nicer than what it was replacing, with no effect. Someone suggested that the radiator wasn't seeing much cool air with the fmic in front of the lower half and the oil cooler in front of the top right corner, so next service I will look at relocating/removing it.

Tried raising the back of my bonnet to let some hot air out and went as high as I could with the original bolts (which was only about 5mm), so need to get some longer bolts and some square tube instead of washers.

Lastly, could it be the fuel pump dying?

Edit: there is also no heatshield on the dump pipe, it came like that but I think that whoever installed it couldn't get the standard heatshield back on..

Cheers for your patience and any opinions/ideas on where to start would be greatly appreciated

Edited April 4, 2007 by bubba

[blind_elk]

My first instinct is the pump dying. The unshielded pod wouldn't be helping, though.

I don't think you have an overheating problem - the engine fan should see to that. The position of the temp gauge needle sounds about right.

[BHDave]

Spend $50 and chuck it on a dyno.

You will know the answer in about 5minutes flat and not have to hope that we know what we are talking about.

+1 on the fuel pump at this stage. Dyno will confirm.

[bubba]

I was thinking the fuel pump too but someone had told me that would cause it to misfire, I think that would be a worse case scenario when it's just about to die. What about the fuel pressure reg? do they ever shit themselves?

Spose I'll just get it on a dyno and have a professional check it out o_O

[mad082]

try cleaning your AFM. if it is dirty it won't read the full amount of air and run it too lean.

also could be a stuffed fuel pressure regulator.

[bubba]

Never thought of the AFM! maybe I left gunk on there when I tried to clean it months ago.. any trick to not leaving any residue with carby cleaner?

And do all RB engines run the same fuel pressure?