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Thread: Advantages & Disadvantages of Turbo w/ B15 transmission.

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Posts: 11-20 of 30
2008-09-11 19:09:49
#11
Originally Posted by Johnny


Where does the third and fourth gear redline MPH wise in the P11 and b15?

according to Autocrossing.com using these gears http://www.brentroad.com/photos/00360628.jpg
B15 transmission
Gear/ ShiftRPM/ Speed @ 7200 RPM
1st/ N/A/ 33.9
2nd/ 4223/ 57.8
3rd/ 4736/ 87.8
4th/ 5184/ 122.0
5th/ 5699/ 154.1
RPM in top gear at 75 mph: 3504

P11 transmission

Gear/ ShiftRPM/ Speed @ 7200 RPM
1st/ N/A/ 36.0
2nd/ 4223/ 61.4
3rd/ 4736/93.3
4th/ 5184/ 129.6
5th/ 5878/ 158.8
RPM in top gear at 75 mph: 3401
[**Both cars using a tire diameter in inches of 23.4**] and
87.8 minus 93.3, which is a 5.5mph difference in third and 122 minus 129.6 is a 7.6mph difference.

Originally Posted by Payu
I would say it depends on you engine setup if you have a engine that keeps making power after 8,000 rpm also have a laggy turbo then you can take advantage of the of the shorter gears because the car will accelerate quicker an you can always stay on your power band. The car that you see on the video he shifts the car at 8,500 rpms so you do the math...
I'm planning on building a VE+T with a GT2876r, I wanted to take advantage of the powerband, so after doing some research on Honda-tech, since most ppl use the Gs-R or Type-r transmission with similar gears in fact shorter gears and than the B15 transmission and have plenty of success with them.
2008-09-11 23:43:20
#12
If you plan on drag racing you wont want anything shorter than a B13 tranny if you are trapping near 120.
2008-09-12 07:00:58
#13
I don't think you wanna be shifting to 5th gear before the end of the quarter. My p11 seems like this with a 205/55r15.
according to the guage rev to 7500:
1st 35
2nd 60+
3rd 97
4th 130+
I never top out 4th gear so I don't know how fast I am going when I bounce the limiter. But it is fast.
2008-09-12 10:49:06
#14
If you plan on using big slicks the B15 will benefit for the launch too... again all depend on the powerband of the engine...
You cant compare a B series Honda engine with a SR20VE-T powerband its way different thats why they take advantage of the shorter gears but if you are planning to use a GT2876 I would say that you should use the P11 transmision....
2008-09-12 22:40:30
#15
Originally Posted by Coheed
I don't think you wanna be shifting to 5th gear before the end of the quarter. My p11 seems like this with a 205/55r15.
according to the guage rev to 7500:
1st 35
2nd 60+
3rd 97
4th 130+
I never top out 4th gear so I don't know how fast I am going when I bounce the limiter. But it is fast.

True, I really want to end the track in fourth.
Originally Posted by Payu
If you plan on using big slicks the B15 will benefit for the launch too... again all depend on the powerband of the engine...
You cant compare a B series Honda engine with a SR20VE-T powerband its way different thats why they take advantage of the shorter gears but if you are planning to use a GT2876 I would say that you should use the P11 transmision....

I'm gonna give the B15 transmission a chance, play with the Boost by gears
if it doesn't work out, i will change to the p11 transmission.
2008-09-19 14:40:55
#16
something that the b15 guys with turbos are doing is putting a maxima final drive into their trannies (spec 6-speed only). it lets them go 100 in 3rd. heres one of the links http://myspecv.com/f/t13201.html . ive got an 05 spec v and am planning on doing this when it finally gets turboed and doing the same on my b13.

fry
2008-09-19 14:50:05
#17
Originally Posted by qfry
something that the b15 guys with turbos are doing is putting a maxima final drive into their trannies (spec 6-speed only). it lets them go 100 in 3rd. heres one of the links http://myspecv.com/f/t13201.html . ive got an 05 spec v and am planning on doing this when it finally gets turboed and doing the same on my b13.

fry


so what FD are you going to put in your B13


It would also seem easier to get a Maxima 6 speed box and just change the bellhousing to a B15 6 speed bellhousing.
2008-09-19 15:12:16
#18
the gear ratios in the maxima tranny with its final drive are way longer than the spec's but if you swap in the maxi's final drive you have a more balanced overall gear ratio plus the b15 has an lsd, im not sure if the maxi does. i plan on a spec v tranny and maxima fd.
2008-09-19 15:19:53
#19
The Maximas do come LSD also.

Do you realize that the Maxima tranny will be better suited for turbo because the gears themselves are longer
2008-09-19 15:21:20
#20
You did not answer my question, what FD are you putting in your B13 tranny
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