Go Back   CLASS RACER FORUM > Class Racer Forums > Bracket Racing

Thread Tools Display Modes
Old 04-13-2016, 09:29 AM   #11
Junior Member
Join Date: Feb 2014
Posts: 15
Default Re: Lazy off the line

Hans, I'm sure it is brother. I had read somewhere that a C6 will eat about 60-70hp vs. a C4 at 30-40?

This car was originally an F code 302 with a C4, I sold that pair to drop in the New combo. If I could go back I would have kept the C4 and had it prepped for this application rather than going with the C6....but, I'm not terribly concerned at this point. My aim is to bracket race this car and have some fun and learn along the way. Future SS build will of course, NOT include the C6
bnsfmachinist is offline   Reply With Quote
Old 04-13-2016, 02:17 PM   #12
Mike Pearson
VIP Member
Mike Pearson's Avatar
Join Date: Mar 2007
Posts: 1,461
Default Re: Lazy off the line

Not enough rear gear. Carb is too big. Cam needs to be advanced not retarded. That is killing the low end. Fix all of that stuff and it will run much better.
Mike Pearson 2485 SS
Mike Pearson is offline   Reply With Quote
Old 04-14-2016, 09:56 AM   #13
Hans Olsson
Hans Olsson's Avatar
Join Date: Nov 2001
Location: Sweden
Posts: 103
Default Re: Lazy off the line

Pressure in the rear tires (10 psi) seems on the low side in my opinion.
Hans Olsson is offline   Reply With Quote
Old 04-16-2016, 06:27 PM   #14
VIP Member
cicero819's Avatar
Join Date: Oct 2008
Location: Aylmer Quebec, Canada
Posts: 1,037
Default Re: Lazy off the line

K.I.S.S is the best principal to use in racing, Adger and Keith have great suggestions, I will deviate from KISS and say to Check your converter, could be junk and it's slipping.
cicero819 is offline   Reply With Quote
Old 04-17-2016, 10:06 AM   #15
Senior Member
Join Date: Jan 2008
Location: Texas
Posts: 535
Default Re: Lazy off the line

Hi. I also believe the heads are too big, especially for the compression ratio. Not enough lower rpm velocity. Since you are just starting out with the idea to be racing for a long time. Buy your self a data logger system. I use Racepak. Most of these issues will show up in a very runs and can actually save you time, money and frustration. I have never seen anyone who finally bought a data logger regret spending the money.
voltdr is offline   Reply With Quote
Old 04-17-2016, 09:19 PM   #16
Junior Member
Join Date: Feb 2014
Posts: 15
Default Re: Lazy off the line

Well, just wrapped up a great weekend at Pacific Raceways up here in WA state. Two separate races sat & sun we went down for both. Basically treated the races as a test and tune to see what we could get out of the car given its current running condition.

Improved ET and 60' a little bit by throwing a bit more timing and jetting down.l (it was a bit fat) Car runs pretty consistent though, it is dial-able (still learning the car of course)

Won in round one on Saturday but lost round two. Bummer was that I was comatose on the line. Worst reaction time I've ever put on a time slip. Lost my composure! (First time going beyond the first round of elim's).

Bigger bummer is that my opponent was so far slower on his dial I only needed to cut a .120 light to have won. Kicked my own butt all night after that one!

Sunday went good, found a good spot on the tree, worst RT was a .090 in three passes. Broke WAY out in the first round. I dialed slower, car picked up.

Fun weekend nonetheless.

You boys offering up advice, I hear ya and gonna put 4.56's under it soon. Gonna try a 750HP and see if that helps, looking at a different manifold as well. But other than that I'll just run as is this season. I'll certainly be digging deeper into the situation this winter, gonna look into a more appropriate cam for sure. Maybe a looser converter.

For now, I'll keep absorbing info from folks like you guys and taking it one step at a time.

Sure is fun though, even in the 12's!

Last edited by bnsfmachinist; 04-17-2016 at 09:22 PM. Reason: Words
bnsfmachinist is offline   Reply With Quote
Old 08-28-2016, 05:07 PM   #17
Junior Member
blasttime's Avatar
Join Date: Feb 2009
Posts: 43
Default Re: Lazy off the line

Originally Posted by Adger Smith View Post
Why is the cam listed as 2 deg retarded with only 10.5 Comp?
Why such a high leave RPM?
Footbrake lower and hit the converter stall harder.
Might be loosing TQ multiplication of the converter.
I would put a little more timing in it before I re jet 2 lower.
X2 on everything
blasttime is offline   Reply With Quote
Old 08-29-2016, 09:36 AM   #18
Run to Rund
Senior Member
Join Date: Sep 2007
Posts: 591
Default Re: Lazy off the line

I agree with the above advice. When I read the initial post, I felt the carb was too big, the intake too aligned to high rpm (especially depending on how it was ported), and the rear gears too mild. Yes, the carb and intake may match the ported heads, but the overall result is consistent with a high rpm combination, and is being killed by a low rpm combination elsewhere.
Run to Rund is offline   Reply With Quote
Old 08-29-2016, 11:53 AM   #19
Dave Turner
Senior Member
Dave Turner's Avatar
Join Date: Oct 2005
Location: Schomberg, ON, Canada
Posts: 980
Question Re: Lazy off the line

How much total timing do you have dialed-in....all in by??
Dave Turner #3110
E&F/SA Mustang
Dave Turner is offline   Reply With Quote
Old 09-27-2016, 11:22 AM   #20
Join Date: Sep 2011
Location: Oklahoma City, OK
Posts: 180
Default Re: Lazy off the line

How tall are your rear tires?

3.90s wouldn't be bad if you had 26-27 inch tire i've been mid 1.50s in a 3200lb amx with 4.10s and 28 inch tires with a much milder than your combo 390. that 1.90 sixty foot definitely indicates a issue somewhere.
pfordamx is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT -5. The time now is 12:37 AM.

Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Copyright © Class Racer.com. All Rights Reserved. Designated trademarks and brands are the property of their respective owners.Ad Management plugin by RedTyger