Well its been a few years since I have been to the track. Since my last trip I have added a a th400 with a brake, an adjustable tq arm,spohn coil overs with 150lb springs in the rear, Spohn pro series anti roll bar, and a fresh set of 28x10.5 et drags.

I could not seem to get the traction that I wanted and my 60' was basically the same as my last trip (right around a 1.6) and my time at the track is limited, so I would really appreciate some pointers to get me in the right direction for my next trip in a month or so.

I spoke with a tech at spohn about dropping the rear coil over spring rate to a 130lbs but he didn't think that it was a good idea. Instead he recommended that I install LCA brackets which is ironically the only suspension bolt on that I haven't done. He also recomended that I check and set my TQ arm andgle to -2*, I have no clue what it is now (cant remember checking it).

Here is a quick recap of the current set up

540 crank hp sbc
Coan th400 brake 4,500 stall
racecraft tubular k-member and arms
Front coil overs cant remember the springs
Spohn TQ arm
Jegster LCA
Jegster weld in SFC
adj Panhard bar
Spohn rear Coil over #150lb springs
28x10.5 mt et drag @ 14lb

Sorry for the rambling on post I kind of threw it together in a hurry without too much thought.

 

my first question was going to be if you have lca relocation brackets.

looks like you have your answer honestly.

rear springs shouldn't do much but hold the car up while it's going down the road. the way the car responds to the hit is typically dictated by the instant center. instant center is a function of lca angle and torque arm length. typically you will want the lca's level with the ground, or slightly upwards from the rearend towards the body mount.

 

Agreed....brackets and set the LCAs in the middle hole.

You probably need more converter depending upon the cam...and maybe gear. If the converter IS 4500 id set the trans brake at 32-3300 rpms. Th400 is overkill for that and will slow it down for sure.

For comparison...my dynod 591hp motor goes 1.31-1.32 in 60' with a 5300 converter and th350.

 

Also...what carburetor are you running? Any larger than a 750 could slow you down in 60'.

A 750 with no power valve will net best results...and yes ive tested all carburetors from 650 - 750 -850 and a qjet.

 

Car has a 750 pro system on it.

I had a th350 in it before and ran the exact times not sure on the 60', I built th400 to be capable of handling a new bbc that I am currently building.

Kind of funny that with all of the money I put into the car that the cheapest suspension mod may give me the biggest gains.

 

I would kill to get a 1.3 60' time. I think I would punch my own mother in the face to pull a 1.4!

 

Hahahaha. Thats funny!!!

Have you tried leaning the carb out at all? If prosystems made it a hair rich you may pick up a little.

What camshaft are you running? I ran 1.60 in 60' running 11.50s or 11.40s...and it seems way off for a 500+hp motor

 

Solid roller comp 260/264@.050 .630 .630 106

The carb seems spot on, but who knows.

 

Huh...what rpm do you shift at and cross the traps at?

 

Well I would like to shift at 6,400, but somerimes have trouble aeeing my light lol,and trap is somewhere in the 6,800 range. Probably not ideal.

 

6400? How did you decide on that rpm? Im just curious...

I shift mine at 7300 and trap like 7800. Thats roughly a 260@.050 cam with. 780 lift in mine.

You may need more gear to make it happier...which would also improve 60'

 

Seemed to be where the engine was happiest on the dyno. I haven't experimented too much with shift points at the track so I might have some room for improvement there as well. I have 4.11 gears in it now.

 

that's a lot of duration. i'd imagine it'd want to spin to 7000+ pretty easily.

 

Do you have a dyno sheet?

 

Huge cam for that size engine. Should want 7000+ if combo is matched correctly.

 

My engine is a 406 so I would think that the cam is appropriate in size.

And I haven't seen my dynosheet in years. Lol

 

Lol. If you remember where is made peak tq and hp thatd solve a lot. Im gonna say you need more converter and gear...and would pickup tremendously