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What difference does 4.10 make over 3.73? My experience

6K views 19 replies 11 participants last post by  AlexLTDLX 
#1 ·
So changed gears from 4.10 to 3.73 because of traction issues... See that in another thread.. Odd nobody out there has an opinion on my suspension to make things better...

2002 GT, 4r75W, 2800 converter, Kennebell 419/RWHP/436TQ

Anyway...
60 ft times
4.10 - 1.54 avg
3.73 - 1.72 avg
and that was with some spinning on the 4.10 and none I could tell with the 3.73

1/8 mile
4.10 - 7.24/95.32
3.73 - 7.86/83.64

Same tune, a little warmer today so safe to say I saw about a .5 second difference in gears.
 
#2 ·
You went slower....never good. Go back to the 4.10's. Get yourself a torque arm, anti roll bar, adjustable shocks, struts and the right springs and some sticky tires and you won't spin using those 4.10's. All the stuff can be used on the street safely but I would probably disconnect the ARB if you were doing a lot of street driving and just reconnect it when you go race.
 
#3 ·
I am thinking 4.56 when I swap back... maybe I can pick up that much time the other way...

I have most of what you say on suspension my thread is here asking for advice on that...
http://forums.corral.net/forums/drag-racing/2271889-new-edge-suspension-setup-questions.html

I know my lowering springs are likely a problem so next step is coilovers in the rear then the front.. I think..

Tell me more about the torque arm vs my baseline suspensions upper control arm kit? I can adjust my IC and AS with that and car launches plenty straight...
 
#5 ·
Yes, lowering springs are not a good choice for the dragstrip.

Don't know if you will only race 1/8 or sometimes 1/4. 4.56's might be a rpm issue though the traps in the 1/4. Don't know enough about your setup. From your results though, sounds like you might have picked a winner with the 4.10's. I didn't see any mention of tires or size.
 
#6 ·
makes sense on the gears, your full weight and more gearing helps torque multiplication. Just need to have some friend video the car leaving to see where in the suspension area needs help. Good set of Tires can be the biggest bandaid to an improper setup suspension. good luck
 
#15 ·
x2. Not a chance you lost 12 mph just from 3.73s instead of 4.10s. Something else happened too. That's like losing 120+ hp at your power level.
 
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#8 ·
6ths can show 12 mph easy, especially in a heavy car like his. less of a difference in a light foxbody.
 
#9 ·
Tires I am running MT Pro Bracket radials 26x10

I should also say my home track doesn't have the best prep out there and I know that contributes because at other tracks I can get it to stick much better.

3 out of 4 tracks in my area are 1/8 mile and that is what I run.. so if it hooks I would like to try 4.56

Current suspension mods:
Rear:
Baseline suspensions Outlaw Upper Control Arm kit (AS running about 113%)
UPR Adj control arms
Baseline suspensions ARB
Strange 10 way single shocks
Spring Ford Racing Lowering spring 1.5"

Front:
Strange 10 way single struts
Spring Ford Lowering 1"
Stock A-arms and K Member
 
#10 ·
na you wold be good I'm thinking. I run 355's but also weigh less and more hp. which all factors in. I imagine the springs are not optimized for the track. have you played with shock strut settings. on my car it was a good difference adjusting settings on a good track. Track has to be good to start testing adjustments to see if it makes a difference.
 
#11 ·
I have played with the shocks/strut settings, but not quite sure on the process.. Should I lighten both together start with the front with the back.. I need to get it on video to see if it tells me anything.. With the Pro Brackets it moves even when spinning so can be hard to tell if it is spinning.. Early in the night it runs 1.63 60ft but after a couple rounds of big tire cars it gets down to 1.52.. So I know I am missing something at least in the first several passes...
 
#12 ·
usually on the strange some will start loose up front and mid to firm on the back. On my car I have real firm on the back but I have Double adj in back. what can happen is that you have good lift on the start but as the front comes back down you can unload the back as the weight comes back on the front. It's like the back comes down and then starts to lift or should say trying to plant the rear slicks but unloads to fast and then spins. Makes sense on the big tire cars, their laying down some rubber to hook better. That's how some tracks prep also. Some will drag old slicks on the track before they spray sticky juice to hook. Practice how you leave, some like to load the converter and some leave at idle. I leave exactly at idle and pull consistent mid 130's 60'
 
#13 ·
I might have a little bit different horsepower than your car and an automatic, but what happens in my car should be the same as in yours. I avoided working on my suspension, aside from normal things like shock, control arms, and an anti-roll bar.

I bought a nice UCA kit from Baseline Suspensions, but could not fit it in my car and adjust it where it needed to be because the UCA mounts were pulled back about an inch.

I upgraded to a little turbo motor last fall. After that, I had problems with wheelies even after the 1-2 shift with a power glide. The car also was pulling the rear wheels into the body, meaning the rear end was driving forward well under the center of gravity. I had to jack the rear springs up as much as possible to minimize the squat. I was almost ready to put 26 inch tires on it to try and help get the rear of the LCA's lower and angled up more to the front. To run my car safely, I had to limit boost to 20 psi or less at the track start. That let me cut high 1.2 sixties, but not reliable and I had a wheelie issue down track when high boost came in.

Every stock location Fox I looked at has an issue with squat. My buddy's grudge car was terrible. He was constantly playing with shocks and ramping nitrous in slow. Anything you do to lower the car will make that worse, and taller tires will make it worse.

I bit the bullet and got the full Wild Rides S box kit. I needed to do this anyway because I am building a bigger engine with a lot larger turbo, and my floor was already a mess.

I got some good videos of my car and watched the rear end. I moved my LCA's up higher in the front until the rear pushed hard down into track. Now my 60 ft times are low 1.2's even at low launch boost. I've yet to hit it with the same boost as down track.

Doing this change, track prep does mean much. I can pull into an unprepped lane and do a 1.2 or 1.3 sixty without even heating the tires. I also lost the uncontrolled wheelies.

I fine adjust my car by changing spring height, lower if I want to reduce antisquat and higher if it needs more hit. I do some shock changes also, but I really don't have to change much unless the track is really bad.

I tried playing with the uppers, but the lowers have a much larger and more predictable effect, so I just left my uppers in a stock location.

Pinion angle does not make a noticeable difference on my car. I just set it so my driveshaft does not skip rope or bind the U joint. The LCA angle moves things all over the place. The UCA's, not so much at all.

I'll see what happens when a get a little more power, but I needed to get the chassis working reliably before stepping things up.
 
#14 ·
Back to the difference between 3.73 and 4.10. Went out this last weekend with 4.10's in the car for the first time after only running with 3.73 before. Noticed 2 things. The car reaction time improved by over one tenth. And I picked up 1.7 mph in the 1/8 mile despite a constant pedal fest in first gear. I expect once the new slicks are on I will see an over 2 mph improvement and I hope a .1 or better improvement in the 1/8 mile. The reaction times went from a consistent .2 or so to cutting regular .07's. I am happy about that.
 
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