Day started off bad.. the way I launched the stock cam kept resulting in horrible bogging and the car just wouldn't move out. Finally started playing with high rpm launches... being on some 77 dollar Kumho ASTs I didn't try to put too much on them but in hindsight I never spun off the line at all so I think they were holding up better than I thought. The last pass of the day (last call.. and my 20th pass) I did a 3200rpm launch and bogged pretty bad... stayed in it and the rest of the pass was ok.

DA was not what I was expecting this early in the season (relative humidity was just under 96% according to the weather data) so comparing the numbers directly is slightly misleading.. but still valid IMHO.

Stock pass was 100% bone stock...RSAs from the factory, spare tire/jack in the car, etc,etc...

LS6 Cam pass was with Kumho ASTs (factory size), Lid, K&N, FRA and Cam (stock tune).


Mixed feelings at the moment... I had an exhaust leak that popped up the day before (a weld on one of my cats is leaking? go GM.. 2 year old converter) and I think it was hurting me a little... also didn't get a tune so stock redline was holding it back for sure. Launching it might improve after a tune or I just need to learn how to drive.

Will be sorting out the issues and hopefully getting back again soon... the rev limiter change alone will put my 3rd gear redline at 112mph instead of 103mph where it is now... removing that shift to 4th will help my traps I'm sure.. the bottom half is where I need to focus I think.

 

I concur.. having to shift into 4th so late in the run is no good. It seems to 60' well for being stock out back. Iron out the issues and go 12's.

Nice times.

 

Tune might help quite a bit. Hard to say for certain without knowing what the AFR was with the cam etc. Prolly wants more timing down low, and might be running rich.

Have you pulled plugs?

 

Will be doing that hopefully tonight... noticed the bumper is covered in black and exhaust tips are caked with black... you are probably dead on. Discovering a big difference between 'you can drive it on stock tune' and 'it will run great' on stock tune. lol

 

I agree with 67. The black soot is a strong sign that its pretty rich too. Still some good times on a new set-up with no tuning. IMO, it will be a completely different machine with the right tune.

 

I dont know quite enough to chime in with these guys.... but what they're saying sounds good enough!

Nah... I do know that much, lol, about the running rich and black soot thing. IIRC, doesn't your ride have a "pile" of miles on it? I thought I remember you saying it had well over 100k on it.... That doesn't have anything to do with your times or anything, I wouldn't think.... just wanted to say those times, and their potential to drop significantly after that tune, are impressive with a high-mileage motor like that....

SN: 20 passes?! We may be related somewhere down the family tree

 

Tune can make a HUGE difference.

Contrary to what many think, there's a big difference between power and performance.

Example, car runs rich. On a dyno with a tune it picks up a bit of hp and torque, but not a lot. In the real world running rich while only down say 10hp, can result in poor ignition and poor response. On a dyno where you make a run with an abnormal type of load it's often not noticed. But in the real world where load is much greater and rapidly varies constantly, the car bogs and lays over because it can't quite get a good cylinder burn going....cylinder stays cool, incomplete combustion, excess fuel builds up, cylinder loads up and the car blubbers all over itself trying to get going.

Result? The car is quite a bit slower than only 10hp would make you believe. It's not that the power is the problem, it's that the extra fuel starts causing extra problems...problems that the longer you stay in it, the worse they get. At least until the rpm picks up enough to actually start clearing the cylinders out of all the excess fuel that keeps loading the cylinder.

While the difference in power isn't a lot, the difference in performance can be huge. The time wasted for the first 100-200ft as the car bogs/sputters etc and struggles to get going, is time that's wasted. An extra second in the first few hundred feet in drag racing is a killer on the back end.

The sooner a cylinder gets good combustion going and gets up to temp, the sooner the car scoots down the track at it's best. Engines are a lot less forgiving off the line, they see the most load that's changing the most rapidly, and tolerate the least amount of problems.

 

Definitely has a lot to do with it, 67. Something as minor as an aftermarket intake can throw things off on a MAF car. I'm surprised it didn't run worse than it did considering the cam was swapped without having it retuned. I know its not a big cam or anything, but it is a big difference as far as the PCM is concerned. My guess is the PCM is pissed, probably pulling timing like a ****, etc.

Get that car tuned, skater. Guarantee you it will run 2-3 tenths and 2-3 mph quicker.

 

Yeah just turned 138K... put the cam in at 137k.. (crazy? me? lol)

I'm not sure it will last forever but everything I took out looked perfect so it should make 200k I would think at the rate I put the miles on.

 

That would put me about where I would expect.. supposed to see about 20rwhp with the cam (nothing crazy). Unfortunately tonight ended up being a nightmare...my exhaust leak was slightly understated.

Was driving tonight and heard a loud boom under the car..thought a tire blew...looked under to find the cat had broken loose complete. Looks like my exhaust leak wanted to be fixed sooner rather than later.