Ok, I just went from the hotcam to a custom grind from cmotorsports in my 383. I also got a custom chip from pcmforless.com. The new cam specs are:

.565/.576
232/242
114

After I got it all together, I noticed some problems. The car surges really bad below about 2300 RPM's now. The surging goes away above that RPM or if you are at more than about 20% throttle.

The car is also noticebaly slower at WOT.

Any idea's? Maybe the tune is off a tad?

Thanks guys.

Oh ya, the car is a 1992 LT1 corvette.

 

What setup did you use to acheive the Dyno numbers in your sig?

 

It was my 383 with the LT4 hotcam and an NX 100 shot. The car only made 370 RWHP on motor, and I see guys everywhere making over 400 with LT1 based 383's. After some research, I decided the best first step to get me to 400+ NA was a bigger cam.

 

TTT, anyone?

 

Are you SURE its installed right? I was sure that mine was, until i went to the track and ran 14s. I missed a tooth and wasnt dot to dot. (also known as "pulling a atljar" by a few board members)

 

Yes, I am sure. If I don't find the answer in thext couple days though, I'll pull it apart again to find out though.

 

Certainly no expert, but wouldn't you expect some surge below 3K with that profile, even with a mail-order tune? I would think that a custom grind would have been matched as well as chosen based on experienced results.

Off-the-shelf cams are usually designed and tested for results. Just throwing in a cam because it sounds like it will provide XYZ results seems to me like buying a pig in a poke.

Apparently, you haven't dynoed it yet. Unless the surge and the lack of performance is obviolusly not supposed to occur based on experience, I'd get it dynoed to see if the numbers and graph are boogered. JMHO

 

He shouldnt have any issues with that cam unless the programming is WAY off, which i somewhat doubt.

 

I put the old chip back in my car and it helped things out a TON. The surge is still there, but is considerbaly less than it was with the new chip. I also got my acceleration back. Too bad it won't idle with the old chip.

I called Alvin a minute ago and left a message for him. Hopefully I get this worked out.

 

Sounds like dynotune time.

 

I know, unfortunately I live in the *** backwards state of Utah. I would have to have all the stuff to burn the chip myself, due to the fact that there are ZERO shops in the whole fuggen' state than can tune an OBD1 LT1. I know the stuff isn't very expensive, but is incredibly intimidating to me to be burning my own chips for some reason.

Oh well I guess.