Possible problem with bolt-ons?
Possible problem with bolt-ons? I posted this up in the dyno section but have yet to get a single response, so let me try it out here:
Ok well I decided to dyno the T/A today on a local dyno that i'll be using for all future dyno needs, so natrually I wanted a base-line to work with. I previously dyno'd the car at a remote dyno to the tune of 330whp/340wtq with the same mods as current (lid w/ K&N, !FRA, Magnaflow catback), nothings changed, and todays numbers were 341whp/347wtq.
Now there's no doubt this dyno is a little on the generous side, but I think this was a bit more than I expected. But anyways, what really caught my attention, aside from the numbers, were 2 things:
1- My A/F was 13.0-13.2 through the entire run, every run. Mind you this is a stock PCM and the only mods are those stated above.
2- During the 2nd and 3rd passes, there was an audible presence of knock starting at about 5300-5500rpm. That last two runs were cut about 500rpm short because of the pinging, yet it still netted 339 & 341whp respectivley.
As I noted earlier, this car only runs an aftermarket lid with a K&N drop in, !FRA mods and the catback. Stock PCM, 93 octane. The day was certainly a little cooler than when I dyno'd it previously, but for the record, the dyno operator (actually a personal friend of mine) did note that I laid down a good deal more than a number of other similarly modded LS1's have. Even my other good friend with a '00 T/A only put down 356whp with an FPIK, same catback and a set of Hooker LT's / ORY. I'm certainly not complaining about the output, but this knocking business has me concerned and that A/F for a stock PCM is definatley out of the ordinary for anythig OEM i've ever seen.
Any ideas?
Ok well I decided to dyno the T/A today on a local dyno that i'll be using for all future dyno needs, so natrually I wanted a base-line to work with. I previously dyno'd the car at a remote dyno to the tune of 330whp/340wtq with the same mods as current (lid w/ K&N, !FRA, Magnaflow catback), nothings changed, and todays numbers were 341whp/347wtq.
Now there's no doubt this dyno is a little on the generous side, but I think this was a bit more than I expected. But anyways, what really caught my attention, aside from the numbers, were 2 things:
1- My A/F was 13.0-13.2 through the entire run, every run. Mind you this is a stock PCM and the only mods are those stated above.
2- During the 2nd and 3rd passes, there was an audible presence of knock starting at about 5300-5500rpm. That last two runs were cut about 500rpm short because of the pinging, yet it still netted 339 & 341whp respectivley.
As I noted earlier, this car only runs an aftermarket lid with a K&N drop in, !FRA mods and the catback. Stock PCM, 93 octane. The day was certainly a little cooler than when I dyno'd it previously, but for the record, the dyno operator (actually a personal friend of mine) did note that I laid down a good deal more than a number of other similarly modded LS1's have. Even my other good friend with a '00 T/A only put down 356whp with an FPIK, same catback and a set of Hooker LT's / ORY. I'm certainly not complaining about the output, but this knocking business has me concerned and that A/F for a stock PCM is definatley out of the ordinary for anythig OEM i've ever seen.
Any ideas?
Originally Posted by 777
you have added mods...they change the a/f...
