Hi I put my car on the dyno today... came up a little short on power. I was hoping to break into the 400 RWHP class! Two baseline pulls with a best SAE corrected 389 RWHP and 385 torque. I will post my graphs when the shop emails them to me. My mods are in my sig. My question is: Am I leaving anything on the table or is that about all I can expect with my mods. The tech did put a scanner on for the second pull and I was getting 2-5 deg knock retard, 5 deg at the start dropping down to 2 deg at 6500. I have about 500 miles on the engine since I installed all the mods listed. I will list the major mods for those who do not want to read my sig. 383 ci, 11.6 compression, 07-467-8 comp cam (230/236) @ .050 .576 /.570 lift, comp- beehive and ti retainers, 1.6 pro mag rockers ported LT4 intake and LT4 heads. heads flow 272 in & 200 ex @.600, long tube headers, no cats, 58mm TB, 42lb injectors, 2800 stall, A4, K&N CAI, Magnaflow catbach with SLP resionator tail pipes. awesome mail order tune by Ion (Mad z28) A/F ratio was steady at low 13:1. HP never dropped off but the rev limiter kicked in around 6500 since I have a Eagle cast crank I did not want to turn it over 6500. Any estimates on how much HP there is to be gained by eliminating the knock retard?

 

Converter Locked or Unlocked?

 

Isnt that crank good till 7500rpm? Im not sure about that cam but from the size you could probly pull it to ~6800. You said it yourself, the hp wasnt droping off, and your heads have some pretty good #'s. Just a thought....

 

not sure on the knock...but without it you'd probably be right at your goal.

have you thought of opening up the exhaust a bit more. maybe a true duals or 3.5" mufflex?
i bet you could pick up 10-15hp over your current setup with a better flowing setup.

maybe just a set of cutouts on the Ypipe for the track.

 

I am going to assume the converter was un-locked... without special programing or hard wiring the lock up function I thought the converter is unlocked at WOT? Assuming that is correct... that must be the main reason A4 cars dyno lower than M6 cars. Any experts out there care to estimate how much more RWHP I would have put down if I had locked my converter??

 

The converter locks up on all LT1s at WOT at 90+ MPH depending on year and gear ratio, so your converter was locked. As for the knock retard, getting rid of it may or may not add more power. My opinion is that you're right where you should be with the cam you have and the automatic.

 

I agree, and the numbers ain't nothing to be ashamed of at all. Go have fun with it now.

 

Take it to the track!

Steve

 

I agree, anyone making over 380 RWHP with that cam is doing well.

I am sure the car is fun to drive and probably feels like it has 400 RWHP anyway.

Lloyd Elliott
972-617-5671
Eportworks.com

 

Good numbers...The only thing I would think about changing is the stall of the converter. I have a similar set up with LT1 heads/intake, shorties, a lil less compression and a smaller cam and our numbers are similar, but I think 2800 is too small of a stall for your combination. But I also don't know the goals for your car. I think my Vig 3600 would be perfect...no its not for sale, I'm just thinking you should step up your stall speed...Take it to the track and have at it!

--Alan

 

I have an LE3 383 and was getting 8 degrees of knock retard
along with other problems it was running low 13s at 104 at best.
I fixed the knock retard and went back to the track. new best was a 12.6 at 109. dropped about .8 sec and gained 5 mph by just losing the knock retard. car felt much stronger at high rpms.
now I just wish I could find out where the other 10 mph have gone.

 

Yeah you have some power robbing issues there somewhere. If I had that kinda cash invested and could only run 12.6 I'd be severly pissed off. Cam only I am almost there just need better traction.