So, Its getting hot out side and I've started to notice something.. My car is detonating under WOT a couple of times per gear...


Im thinking its water injection time....

Setup.

98 1.8t quattro manual
APRchip
forged DV
KNN drop in
Full heat shield
2 2in holes cut in the stock filter box before filter
Borla exhaust w/ first muffler removed and replaced with an exhaust cutout

Boosting to 17-20psi, detonates at 20 and drops to 17, then bumps back up to 20..

Only running 91 chevron (dont want to run 100 @76 for the street....)

Whatcha guys think? Water injection time?? going to be going to a GT2871R... when my turbo blows up. (it leaks very very slightly...)

Andrew

 

It shouldnt be detonating in the first place, so water injection might only cover an underlying problem up. Scan for fault codes. If no codes, change your plugs, possibly to a one step cooler plug. 20 psi is pushing it for the stock plug heat range. NGK BKR6E is the stock equivilent, and BKR7E is one heat range cooler, try those.

 

your heatsoaking the ic not detonating. Water/meth or a fmic will cure that. also a heat range coolder plugs with a gap of .028 should be a given with a chipped car.

 

Spark plugs and check for codes... Olky Dokly...


Did I mention its 100 Degrees here?? I might go with some water injection too... but I might spray the intercooler to keep my mixture ok.. till I get the turbo and run a custom tune..

 

You might have some carbon build up on the valves & pistons.
Yea, heat soak will cause a lot of this, so will a very aggressive tune.

Scan for codes, check the plugs. If they all check out. I would run some injection cleaner through the car. If it still happens, try adding 2g of race gas. If it goes away, you need to retard the timing a little. You can just remove 1-3deg with Lemi, it should stop the detonation, & give you more POWER since you will be able to hold boost.

Getting a BIGGER IC will help also [:@]

 

Pack the ol SMIC with a bag of ice just for fun and see what happens. Im tempted to try it just to see how much of a difference there is in IAT's with vag com.

 

This is a drag racing trick......
Get one of the 2-3g garden sprayers, fill 1/2 with water, then the rest with ice. Spray the intake, & IC for 2-5min, then drive, it will lower the IAT's quite a bit, & it's far eiaser then getting at the IC with a bag of ice.

 

Clean your MAF I was having the same issue with the summer weather my car was pinging. If yourMAF is reading less air than is entering your engine it will cause you to run lean. I tried everything to correct the problem. I finally went to Autozone spent $5 on MAF cleaner pulled my airbox apart and cleaned my MAF and problems are gone. I recomend a new set of BKR6E's and cleaning your MAF.

 

yeah get you a 7 dollar bottle of seafoam and follow directions on back to but some down your intake man....