probs at the dyno after cam install
probs at the dyno after cam install i went to the dyno the first time after installing my cam last week. i dont have a scan of the sheet but on the first pull i put down 360 rwhp and the 2nd pull 366 rwhp.
my torque looked good but on the hp powerband, at 5200 rpms i had some kind of spike where the power went down then back up. i should be putting down 380-390rwhp with this cam. i talked to the tuner and the first thing i thought about was my bosch plugs. i replaced them with ngk's. i took the bosh's out and they were covered in black soot from it running rich. he also said try replacing the maf ends with some that still have airfoils...mine are cut out.
im gonna replace my paper filter with a k&n too. other than that can anybody think of anyhting that can cause a spike like that or a 20 hp loss?
only other thing i thought of was the timing chain. i reused my stock chain..though it had a little slop in it. when i put it on i double checked the dots were perfect. but if the timing was off i would know it i think.
my torque looked good but on the hp powerband, at 5200 rpms i had some kind of spike where the power went down then back up. i should be putting down 380-390rwhp with this cam. i talked to the tuner and the first thing i thought about was my bosch plugs. i replaced them with ngk's. i took the bosh's out and they were covered in black soot from it running rich. he also said try replacing the maf ends with some that still have airfoils...mine are cut out.
im gonna replace my paper filter with a k&n too. other than that can anybody think of anyhting that can cause a spike like that or a 20 hp loss?
only other thing i thought of was the timing chain. i reused my stock chain..though it had a little slop in it. when i put it on i double checked the dots were perfect. but if the timing was off i would know it i think.
A sharp drop is your car pulling timing. You should be datalogging your pulls and adjusting timing as necessary. Also, sounds like the car is running rich, you should be logging the wideband readings for your pulls and adjusting the WOT tables for proper AFR.
That dip is most likely knock retard. You really need to log data and see what is going on. A overly rich mixture can also cause knock. Do you have a tuner that can tune the car in your area? Might be your best bet to get the car done right.
I doubt your timing chain is off. See if peak torque is at 4700. If it is, your OK with the timing chain.
Is there a tune in the car?
I doubt your timing chain is off. See if peak torque is at 4700. If it is, your OK with the timing chain.
Is there a tune in the car?
Originally Posted by Billdog350
A sharp drop is your car pulling timing. You should be datalogging your pulls and adjusting timing as necessary. Also, sounds like the car is running rich, you should be logging the wideband readings for your pulls and adjusting the WOT tables for proper AFR.
