AP2 Block with an AP1 transmission?

[Coop]

Does anyone have an AP2 engine and is using an AP1 transmission? If yes, now does the gearing affect the drivability of the car?
I am thinking of using a AP2 block to replace the AP1 that "left the building" this weekend.

Coop

[Goku]

did it break? what happen

[repiv]

The car will basically feel the same except that you only go to 8000 rpm redline. Max speed in each gear will be reduced accordingly.
To know what it would feel like, drive any stock AP1 and don't go over 8000 rpm.

Use this gear calculator for AP1 and type in 8000 where it says 9000 and you'll all your speeds for each gear.

http://www.turnzero.com/technical_resources.php?resource=gear_calculator

[Coop]

thanks,

but I thought the AP2 tranny had some different gearing to better us the higher torque.

[repiv]

thanks,

but I thought the AP2 tranny had some different gearing to better us the higher torque.

Yes, the AP2 tranny has more aggressive ratios in the first 4 gears.
But weren't you asking about putting an AP2 engine into an AP1 car, thus using your existing AP1 transmission? Or did I misunderstand?

Now, if you mate an AP1 transmission with an AP2 car, then having been used to the low end grunt of the AP2 tranny, you will then feel that the car is a bit more sluggish, however, my first reply still applies. It'll be just like an AP1 car that has a limit of 8000 rpm.

[Coop]

Thanks, now I see what your saying. got a bit lost, from the link, it shows the gearing the same in both.

[repiv]

Thanks, now I see what your saying. got a bit lost, from the link, it shows the gearing the same in both.

You have to look at the "transfer" ratio. This is the S2000's secondary reduction ratio. It is this difference that makes the first 4 gears "seem" different. Notice how Honda altered the ratios for gears 5 and 6. This makes those gears almost the same for both transmissions because of the 2ndary reduction ratio.

[wildncrazy]

To me the "right" set up is an AP1 engine on an AP2 tranny or an AP2 engine on a AP1 tranny.

The AP1 needs just a tad more low end grunt which the lower gearing of the AP2 tranny gives it without too much sacrifice of speed in a particular gear. The AP2 could benefit from a few more mph per gear. Many with the AP2 say the gears are too low, especially first since you run out of revs faster than the AP1.

The people I know who have had AP1s and AP2s prefer the AP1 on the autocross course because they have to shift more often on the AP2 due to the lower rev limit and because most autocross courses are designed to be 2nd gear courses. The AP2 needs to go into and out of 3rd a lot (because 2nd gear in the AP2 doesn't allow you to go as fast, once again due to the lower gearing and the lower rev limit) with the resultant chance for an error or upseting the car balance.

[alvanderp]

The people I know who have had AP1s and AP2s prefer the AP1 on the autocross course because they have to shift more often on the AP2 due to the lower rev limit and because most autocross courses are designed to be 2nd gear courses. The AP2 needs to go into and out of 3rd a lot (because 2nd gear in the AP2 doesn't allow you to go as fast, once again due to the lower gearing and the lower rev limit) with the resultant chance for an error or upseting the car balance.

AP1's end up going to first alot for auto-x for slower stuff though. Its 6 of one, half dozen of another. Like you noted, somewhere in the middle is most preferable, AP2 with AP1 trans, or AP1 with AP2 trans. If you have alternate rear-end gears in the car, this obviously changes a bit.