austrian type-R

Top speed vs AutoX TRANNY

I don' t know what to do.

I droved on the Autobahn for a Topspeed run with 4 people in the car (including me) and I maxed out at 265 kph indicated. From 200 - 265 it was such a RUSH, it took about 10 seconds I guess. This was with 1.2 Bar of boost, 608 mm tire diameter and 8800 revs (cut off)

Tranny is stock (we have JDM 4.785 final drive)

I can convert to USDM final drive (I have it at home already) to get a top speed for about 290 kph. But I will lose about 300 rpms for AutoX, which is not so good I think (for turbo lag).

I can convert to LS 5th gear for Top speed about 295, but this cost again money.

Perhaps converting to a larger finaldrive is better, cause I can get more power to the ground and therefore acceleration is better, or at least it is not bader than with a shorter fd.

Perhaps I can convert some rpms for AutoX with smaller tire diameter. And rise the redline about 300rpms to get some speed back again for the straights on autoX.

Perhaps a larger fd is also better for DRAG racing, cause of the better traction?

PS: A 6 gear tranny would be nicer.

B20C5 Turbo

Hehehe... Great question. To be quite honest, you will not get any kind of reputable response on this site regarding that question. In fact, you may find it very hard to get an accurate response to that anywhere on the internet. Here's why:

For the most part, many of the people here and elswhere have not had the opportunity to open and compare all of the components inside the various "B series" transaxles. Those of us who have that experience invariably guard this information as secretive since it ultimately leads to proper engine/geartrain tuning for success in each of the specific racing venues.

I will say this, however: You need to make a choice between AutoX, Drag, and Top end MPH. Each venue will have an exclusive set of components.

SiRkid

**** thats high! USDM cant go that high! well maybe with thehigher rev limit...hmmm.
wtf? im confused.

austrian type-R

Sure that high. With JDM 5th gear and USM fd + more revs and a bit more tire diameter. 300kph, here I come

DSF

8800rpm + 608mm (23.9") tire + ...

JDM .848 5th + JDM 4.785FD = 247.80kph (153.98mph)
JDM .848 5th + USDM 4.40FD = 269.48kph (167.45mph)
LS .714 5th + JDM 4.785FD = 294.32kph (182.88mph)
LS .714 5th + USDM 4.40FD = 320.07kph (198.88mph)

and for ***** and giggles...

LS .714 5th + USDM 4.26FD = 330.59kph (205.42mph)

...does not account for tire expansion (or explosion )

austrian type-R

vorrect, and I would up the revs to 9200, this are about 300koh with USD 4.400 and JDM 5th.

rice4life

iTrader: (3)

i have a jdm ys1 tranny with 4.4 FD. this tranny is almost identical to usdm ITR tranny but in cable form. i put in an LS 5th gear to get better cruising milage. if you don't use 5th gear in autoX, then you should swap out 5th gear that way you still have good acceleration from 1-4 gear. all b-series gears are interchangable(cable and hydro).