4.56 Or 4.88?

[ERStettin]

I went to Cedar Falls Raceway today. I have been there the last three weekends. Last weekend I was running the 4.56 gear. This weekend the only thing I changed was swapping the 4.56 for a 4.88. The weather was great both weekends though there was a head wind of about 10 knots or so today.

I made three passes last weekend with the 4.56s’ and one of them was my best pass ever. Here are the passes from last weekend.

LAST WEEKEND
FIRST PASS
R/T - .504
60’ - 1.445
330 - 4.395
1/8 - 6.848
MPH - 100.97
1000 - 8.986
1/4 - 10.782
MPH - 125.87

SECOND PASS
R/T - .520
60’ – 1.483
330 – 4.449
1/8 – 6.898
MPH – 100.65
1000 – 9.028
1/4 -10.811
MPH – 126.65

THIRD PASS
R/T - .343
60’ - 1.447
330 – 4.397
1/8 – 6.842
MPH – 100.61
1000 – 8.969
1/4 – 10.754
MPH – 126.51



As you can see, the MPH and ET was better last weekend with the 4.56’s but the 60fts’ were MUCH better this weekend with the 4.88s’. I usually crossed the traps at 7,000 rpm or so with the 4.56’s and today I was crossing about 7,300 to 7,400 or so.

What do you think I should do here? Should I swap back to the 4.56 gears or should I keep the 4.88s’ in the car and give them another chance during a day with no headwind? I am kind of wondering if the 4.88’s are too much gear for my set up? My set up only makes good power to about 7,000 rpm. After that, it falls off a cliff. I was hoping the decrease in 60ft time with the 4.88 would help offset what I would lose up top but it doesn’t look too promising. I did manage to get a 10.76@123.93. I guess I am stumped on which way to go. Thanks in advance to all who reply.

THIS WEEKEND
FIRST PASS
R/T…...130
60’……1.489
330…...4.503
1/8……6.994
MPH…98.77
1000…9.141
1 / 4….10.950
MPH…122.73

SECOND PASS
R/T…...407
60’……1.423
330…...4.399
1/8……6.876
MPH…98.82
1000…9.012
1 / 4….10.823
MPH…123.06

THIRD PASS
R/T…...171
60’……1.409
330…...4.391
1/8……6.868
MPH…98.12
1000…9.010
1 / 4….10.822
MPH…123.29

FOURTH PASS
R/T…..-.121
60’……1.437
330…...4.435
1/8……6.914
MPH…98.37
1000…9.055
1 / 4….10.868
MPH…123.17

FIFTH PASS
R/T…...095
60’……1.413
330…...4.368
1/8……6.835
MPH…99.11
1000…8.963
1 / 4….10.767
MPH…123.93

[Dale McPeters]

How tall of a tire 26 or 28?

[ERStettin]

28 inch tire Dale.

[QWKSNKE]

I think you should go back to a 4.56. Seems like 4.88 is to much for your setup

[Dale McPeters]

Originally Posted by QWKSNKE

I think you should go back to a 4.56. Seems like 4.88 is to much for your setup

I agree.

[Craig K.]

I would tend to agree that if your crossing at 7300-7400, and you loosing power after 7000, I too would think the 4.56's are the better choice.
Plus look at your 1/8 mile speeds, looks like your already stating to loose some at that point.

[ERStettin]

I have been thinking about this and one of the things I noticed is I did run within .001 of my best time and this was with a set of gears that I have NEVER run with. I think I need to give them some more seat time before I dump them.

I am going to adjust my shift points by 150 rpm or so and see if that helps keep the car pulling through the traps. I think it might help me. If the car can 60 ft in the low 1.40s' all I have to do is get it in 3rd gear by the 1/8th or so and I can get those mid 10's with these gears.

I am not going to sell the 4.56s' just yet but I am not going to give up on the 88s' with just five passes with them under my belt either. Thanks for the replys everyone. I appreciate it.

[93Cobra#2771]

I agree, give a little more time/more testing before swapping back out...

[coupe]

Swap back. Change some suspension stuff to get the 60' where you want it
or spray it

Let your motor do what it needs to do.