Pinging/detonation when at high boost (3S-GTE)

[MWP]

0.8mm from memory.
Ill recheck the plugs too, might be able to see det on one or more of them to possibly isolate the cylinders at fault.

I have a couple of quite noisy injectors, im wondering if one might not be flowing properly and leaning out the cyl.

... lots to check tomorrow.

[hemi twofifteen turbo]

Has the problem just appeared or is it you've never been able to tune it to run without knock at that boost?

If just appeared and nothing else has changed then I would go with fuel swap/check plugs etc, or check someone hasn't sat on your laptop and put a rouge fuel/timing setting around that area in the map.

If you've never got it to run the 18psi w/o detonation give it fuel!! 12:1 IMO is no where near enough, esp if you have a relatively small exhaust housing.

[SillyCarS]

ill mention fuel pressure reg as no one else has yet

some quality answers here +reps all round (not that anyone cares lol)

hope u get her goin cos im gunna come down and have a look

[MWP]

hope u get her goin cos im gunna come down and have a look

Make sure you find me and say hi

Ill be there competing regardless.
If i cant get the pinging solved, ill just dial back the boost until it stops.

Gotta beat my previous best of 37.71 !!!

[MWP]

If you've never got it to run the 18psi w/o detonation give it fuel!! 12:1 IMO is no where near enough, esp if you have a relatively small exhaust housing.

Interesting... how does a small exhaust housing have an effect?
And yes, it is small, its a high-flowed CT26 (factory exhaust housing/turbine).

All of this is making me want to install a water/methanol/acetone injection system.

[Duk]

Interesting... how does a small exhaust housing have an effect?
And yes, it is small, its a high-flowed CT26 (factory exhaust housing/turbine).

All of this is making me want to install a water/methanol/acetone injection system.

Simple. Small exhaust housing causes more back pressure in the exhaust manifold. This causes more heat retention in the exhaust valves and combustion chamber. Higher temperature combustion chamber/exhaust valve are a potential source of pre-ignition.

[jonathan yee]

as much as i agree that the stndard ct26 housing is small i wouldnt think it'd be the restriction/problem at such low rpm. otherwise every factory turbo'd gen2 3sgte would be having the same problem.

do you know what size comp wheel the hiflow is running?

[jonathan yee]

actually then again he's getting 18psi at 3500rpm.......which is far from factory, so maybe your right......mustn't be the biggest of comp wheel's most hiflow's i've come across don't get hard boost till 4000rpm, sound's like you have something nice and responsive more like a "ct20b".

[paradox616]

what's your intercooler setup like? have you checked your intake temps?

[thechuckster]

what's your intercooler setup like? have you checked your intake temps?

in post #5 "The IC does an awesome job, GM air-temp sensor placed just before the TB, says that on boost, temps are almost at ambient."

[mattysshop]

what sort of Turbo manifold? on my mates CT26 setup (before going custom mani and GT28R) the stock cast mani was restricting.. swapped for just a 3mm wall stainless ebay job.. which glowed red hot all the time.. but oddley never cracked (18months of use on his engine then swapped to another engine), gained 17hp @ the wheels, and EGT's dropped, this was measured at the dump pipe (twindrop custom), not in the manifold... but it was done relativley back to back with the only mods from one to the other was the cast man > aftermarket mani..


similar to 4EFTE's the first thing that should be done is throw the cast manifold in the bin, due to number 3 runner being so restricted buy the stud casting.. it causes EGT's in cylinder 3 to go nuts when more boost is added..

excuse the reply if you already have an aftermarket manifold

[Duk]

in post #5 "The IC does an awesome job, GM air-temp sensor placed just before the TB, says that on boost, temps are almost at ambient."

Maybe double check in case IAT sensor is faulty???
More or less pinging with different temperature weather???