Best gear for 9.90

[Charlie Yannetti]

Originally Posted by Lenny5160

Are you saying that the car comes off the stop much harder, your converter got more efficient, but you didn't gain any MPH?

Was there a measurable gain anywhere? Could you stay on the stop longer?

Although I didn't mention MPH, I'm up between one and two.. also, I usually do stuff to try and take time out of the box.. not put more time in.. and I really don't like carrying 3.00 in the box either...

[Shake & Bake]

rob7181,
Going from the 4.10 your running to say a 4.33 would only be a 5% increase, but going to a 4.56 is going to be a 9% overall increase in performance. Plus you should pick up around 3mph.

[Tom Goldman]

Like Charlie ,I run Select converters . I went to 4.56 gears from 4.29 in my Vette which weighs in at 2400# .
I picked up 2 mph with an increase of 250 trap rpm .
converter efficiency went from 10% slip to 5-6%. AND very importantly , the converter temperature dropped way down when coming off the stop.
Since Charlie's car is a '27 Roadster, one of the hardest cars to get MPH out of I'm not surprised by the lack of improvement in speed.
I would defiantly recommend 4.56 gears in your car.
Racers get too hung up on trap rpm's , if your engine is still pulling at the stripe ,let it eat !

[Keith 944]

^^^^^^this

[Dano]

Originally Posted by Tom Goldman

Like Charlie ,I run Select converters . I went to 4.56 gears from 4.29 in my Vette which weighs in at 2400# .
I picked up 2 mph with an increase of 250 trap rpm .
converter efficiency went from 10% slip to 5-6%. AND very importantly , the converter temperature dropped way down when coming off the stop.
Since Charlie's car is a '27 Roadster, one of the hardest cars to get MPH out of I'm not surprised by the lack of improvement in speed.
I would defiantly recommend 4.56 gears in your car.
Racers get too hung up on trap rpm's , if your engine is still pulling at the stripe ,let it eat !

Did the cars reaction improve?

[Charlie Yannetti]

In my combination, the gear change didn't seem to affect my reaction time.. I didn't change any numbers in the box..

[Dano]

Originally Posted by Charlie Yannetti

In my combination, the gear change didn't seem to affect my reaction time.. I didn't change any numbers in the box..

No improvement on my cars reaction either with a 4.10 to 4.57 change.