jwgroovin

I have the C&L CAI and C&L 93 Octane tune for the Predator (latest Predator r18 software and latest tune off the DiabloSport website), plus a tankful of Amoco 93 octane gas. I'm pretty pleased with it with one exception:

If I get on it from a standing start, I've noticed what appears to be engine detonation in second as I scream to third. It's pretty consistent, but I haven't noticed it if I'm already rolling in second then have to get on it again (like slowing for a light, which turns green and there's nothing between you and the horizon but open road...).

Has anyone noticed the same thing? Also, is anyone running 93 octane but using the 91 octane tune? I've noticed a lot of folks here use the 91, but finding real 91 octane around here is a bit hard. Just 87, 89 and 93. I'm not sure knocking back the timing is worth it for 87 at this point.

I've already called a speed shop that can tune the file parameters for me on a dyno--they are a certified DiabloSport shop, but was wondering if my issue is an exception and not the rule.

John

somewhatdamaged

Hey John,
I wish we could get 93 octane in So Cal, but nevertheless my 93 octane adjusted for 91 is working pretty good. I haven't noticed any pinging myself. I would get the custom tune if it's not too pricey bet they can give you a decent power boost to boot. I'm probably gonna go with one myself when I purchase my 4.10 gears! Good luck, hope you are able to resolve...you could also give Cole a call, see if he has any suggestions.
Somewhatdamaged

black gt 2005

i use sunoco 94 octane no problem. maybe amoco gas is cheap crap or cheating you with 89 octane and saling to you as 93 octane ,this does go on in some gas stations.

jwgroovin

The speed shop asked if I intended to do much at the drag strip ("no") so he said all I really needed beyond a dyno tuned update for a kick hiney street machine was the gears, lowering one inch, 18"s, and upgraded front brakes.

The tune was quoted as anywhere from $50-$150, depending on the time needed to adjust everything. I'm dropping by there on Saturday to discuss it all. I hate to drop another couple grand on the car, but then again...

And "Cole" is....?

John

jwgroovin

Yeah, I should probably fill up with another brand, and see if that helps.

SixtySix

Also, you could just retard the timing a little to get it out of detonation if it's still a problem after you get another brand of gas.

Faber

I pinged right around 4500-5000 rpms with a 91 octane tune, and ended up richening the mixture by 4 points, and retarding the timing by 3 degrees to get rid of the ping. this worked fine when it was just me driving the car, but if someone else was riding the ping would come back. so i ended up rolling another 1.5 degrees of timing out of it. I am in Tucson, AZ, and we dont have very high quality fuel around here. chevron, and mobil have been the best i have seen so far.

jwgroovin

Yeah, I'll fill up again in the morning, and give it another go. If it's still there I'll knock off a couple of degrees and go from there.

I was just curious is the issue was showing up with everyone. It's only when I've got the pedal on the floor on in 2nd, so it should be pretty easy to test and adjust.

Vegasjay

What he said. Exactly what I would do...

tmcolegr

Cole & DiabloSport (561) 908-0040 ext. 212

SixtySix

Can't be any worse than it is in metro Phoenix, can it?

Interesting because I'm running the Diablo 91 Octane tune, and I was able to advance the timing by 2% with no detonation happening.

porsche

stop fu##ing around Get a tune and watch your knock on the dyno it will take power away! Also i run 91 with more spark adv then the 93 tune so its your gas.

jwgroovin

Everything is poitning to the gas, but I will get to a shop as soon as I can, but the performance shops around this rural part of Maryland are a bit scarce, and scarcer still that can provide me with the customized Predator tune. The first shop I've called wants me to drop off the car for the entire day (weekday) which is NOT an option.

I just filled up with Mobil 93 octane, and if I still get some detonation I'll knock back the timing a few degrees until I can get it into a shop.

porsche

You dont need a custom tune . Tune it yourself with the diablo!