Detonation is GONE!
Detonation is GONE! I know lots of people have this problem, so I wanted to post my experience.
Some time back, I posted a thread here called WOT=rattle. Under load, I had some pretty nasty sounding rattling and it was driving me crazy. I originally thought it might be related to engine temperatures, as it was generally worse in hot weather (which, in Houston, is 10 months out of the year). Another possibility was leaky valve stem seals, since I found oil on the threads of #7. The oil appears to be more related to PCV bypass. I took it to G-Force for a look and they ran a compression and leakdown test, and everything passed. I took it back for a tune and they were able to get this out of it:
Baseline:
Peak hp - 308
Peak tq - 310 (I think...it was in that range)
After tune:
Peak hp - 318
Peak tq - 326
It should be noted that a Magnaflow catback was installed that day. I don't know if it was installed before or after the baseline dyno run. Maybe Mike can shed some light there.
It was still detonating a little, but Mike was able to get it much more under control. The curves on the dyno sheet were MUCH smoother after the tune as well. There's a long story behind it (see the Racer's Lounge), but one of my cats got pretty badly damaged and both were badly clogged. I ordered a new set of Pacesetter headers and a TSP catted y-pipe. G-Force installed everything and then retuned.
After LT headers and new y-pipe/tuning:
Peak hp - 333
Peak tq - 335
And the best part: NO MORE DETONATION!!! So a good tune and some better flowing exhaust fixed my problem.
Reader's digest:
Had detonation.
Replaced the entire exhaust setup.
Got a tune.
No more detonation.
-Mike
Some time back, I posted a thread here called WOT=rattle. Under load, I had some pretty nasty sounding rattling and it was driving me crazy. I originally thought it might be related to engine temperatures, as it was generally worse in hot weather (which, in Houston, is 10 months out of the year). Another possibility was leaky valve stem seals, since I found oil on the threads of #7. The oil appears to be more related to PCV bypass. I took it to G-Force for a look and they ran a compression and leakdown test, and everything passed. I took it back for a tune and they were able to get this out of it:
Baseline:
Peak hp - 308
Peak tq - 310 (I think...it was in that range)
After tune:
Peak hp - 318
Peak tq - 326
It should be noted that a Magnaflow catback was installed that day. I don't know if it was installed before or after the baseline dyno run. Maybe Mike can shed some light there.
It was still detonating a little, but Mike was able to get it much more under control. The curves on the dyno sheet were MUCH smoother after the tune as well. There's a long story behind it (see the Racer's Lounge), but one of my cats got pretty badly damaged and both were badly clogged. I ordered a new set of Pacesetter headers and a TSP catted y-pipe. G-Force installed everything and then retuned.
After LT headers and new y-pipe/tuning:
Peak hp - 333
Peak tq - 335
And the best part: NO MORE DETONATION!!! So a good tune and some better flowing exhaust fixed my problem.
Reader's digest:
Had detonation.
Replaced the entire exhaust setup.
Got a tune.
No more detonation.
-Mike
TECH Apprentice
Joined: Jan 2005
Posts: 396
Likes: 0
Glad things worked out for you. How much was the catted Y pipe and do they make one for stock manifolds/shorty headers? My old Formula used to detonate like crazy and we tracked it down to the PCV sucking oil like a fish. A catch can, new plugs, and some top end cleaner fixed it.
Launching!
Joined: Jul 2004
Posts: 291
Likes: 0
Glad to hear you got the detonation under control.
I ended up using a MAFT.
BTW, how much did you spend on the LT and Y pipe?
Just curious looking at the dyno numbers for only a 15 horse and 9 TQ gain???
Is that all LT's and Y pipe good for?
I was thinking of getting LT's and a new Y pipe but geez.
I ended up using a MAFT.
BTW, how much did you spend on the LT and Y pipe?
Just curious looking at the dyno numbers for only a 15 horse and 9 TQ gain???
Is that all LT's and Y pipe good for?
I was thinking of getting LT's and a new Y pipe but geez.
I paid $700 for the headers and y-pipe from Texas Speed -------->
The numbers are pretty much what I expected for this car. Aside from the exhaust, the only real performance mod is the lid. That, plus 93,000 miles on the odometer and I'm pretty freaking excited that it did as well as it did, so don't **** on my parade!
Headers in and of themselves aren't a huge performance mod. They are a foundation upon which to build. Anyone who has ever swapped heads and cam will tell you that doing it before replacing the exhaust manifolds means you won't get the max gains out of the setup.
-Mike
The numbers are pretty much what I expected for this car. Aside from the exhaust, the only real performance mod is the lid. That, plus 93,000 miles on the odometer and I'm pretty freaking excited that it did as well as it did, so don't **** on my parade!
Headers in and of themselves aren't a huge performance mod. They are a foundation upon which to build. Anyone who has ever swapped heads and cam will tell you that doing it before replacing the exhaust manifolds means you won't get the max gains out of the setup.
-Mike
Last edited by chupr0kabra; Jun 14, 2005 at 03:29 PM.
Launching!
Joined: Jul 2004
Posts: 291
Likes: 0
Originally Posted by chupr0kabra
I paid $700 for the headers and y-pipe from Texas Speed -------->
The numbers are pretty much what I expected for this car. Aside from the exhaust, the only real performance mod is the lid. That, plus 93,000 miles on the odometer and I'm pretty freaking excited that it did as well as it did, so don't **** on my parade!
Headers in and of themselves aren't a huge performance mod. They are a foundation upon which to build. Anyone who has ever swapped heads and cam will tell you that doing it before replacing the exhaust manifolds means you won't get the max gains out of the setup.
-Mike
The numbers are pretty much what I expected for this car. Aside from the exhaust, the only real performance mod is the lid. That, plus 93,000 miles on the odometer and I'm pretty freaking excited that it did as well as it did, so don't **** on my parade!
Headers in and of themselves aren't a huge performance mod. They are a foundation upon which to build. Anyone who has ever swapped heads and cam will tell you that doing it before replacing the exhaust manifolds means you won't get the max gains out of the setup.
-Mike
Thanks for the info.
I'll probably go for the converter before the LT's for now I guess.
Good luck with your setup.
Glad you got the problem taken care of. I too had a detonation problem w/my 02 LS1. I had a local guy who only works on Vettes, Camaros & Birds do a tune on mine and there's no more ping and a lot more pull. It can clearly make a big difference when someone who knows what their doing reconfigures the timing and fuel on these cars.
