Need help selecting a manual trans

[FastGT94]

Looking for a trans for a street strip combo (60% strip 40% street)

I WILL NOT GO AUTO

Current trans:
Busted T5z
1st 2.95
2nd 1.99
3rd 1.33
4th 1.00
5th 0.63

Choices are:
TKO500 (MMR Pro trans 750)
750 HP Rating for cars running 10.00 @ 138 or slower
Ratios:
1st 3.27
2nd 1.98
3rd 1.34
4th 1.00
5th 0.68

TKO600 (MMR ProTrans 900)
900 HP Rating for cars running 9.00 @ 150 or slower
Ratios:
1st 2.87
2nd 1.89
3rd 1.28
4th 1.00
5th 0.64

Astro / G-Force T5 650 FWHP / 525 FWTQ
1st 2.95
2nd 1.99
3rd 1.36
4th 1.00
5th 0.62

MMR Deburrs and Heat Tempers gears 1-3 and the cluster on the TKO500 and gives it a 26 spline input shaft (stock TKO 500 is 10 spline)

MMR Deburrs and Heat Tempers gears 1-4 and the cluster on the TKO600 and also Heat Tempers the 26 spline input and 31 spline output shafts

I'm not sure on a beefed up T5 since I heard the case is still the weak point from what I'm told, but there have been some decent arguments for a G-Force or Astro T5, so I'll include it. I really feel the TKO500 or 600 are better choices however... Although some people are saying that the TKO500/600's are just 3550's with different internals and the case is indeed more prone to cracking... argh...

The argument presented to me for the TKO500 instead of the TKO600 is the higher torque multiplication for the first gear ratio difference between the two, but I'm not sure that the difference is high enough to really make a huge difference.

I know I'm not making enough power to justify a 900 hp rated trans now, but if I ever hit 600+ hp, I want the trans to take it, so I'm buying up now in preparation for future mods.

Thanks,

 

[Joey7508]

I have a d&d viperspec 6 speed. Love it. I had a tremec 3550 before. I really didn't need the viperspec at the time I bought it, but I bought it with a turbo combo in mind. It was pricey, but I am glad I decided to buy it. Super strong, and highway friendly.

 

[FastGT94]

What about at the Drag Strip? It seems the gear ratios aren't exactly track friendly
Looking at the Ford spec T56, it looks like the 3-4 shift is a big factor compared to other transmissions.

I shift at 6300:
T5z 4th gear 4600
TKO500 4th gear 4600
TKO600 4th gear 4800
Ford T56 4th gear 4300
Viper T56 4th gear 4700

So it looks like you're losing a lot of RPM's with the Ford T56 over the other Trans because 3rd is a shorter gear in the T56 And the Viper T56 has a tall 1st gear at 2.66 which takes away from 60' in lower horsepower applications...

 

[SVT32VDOHC]

I haven't heard anything about Astro Performance but I have noticed their transmissions are cheap alternatives to TKO stuff. I would like to try them someday, but fortunately, my T5 is working good....it was just rebuilt 1 year ago!!

 

[PUNISHER RACING]

G force t5 gets my nod

 

[FastGT94]

Are GForce and Astro Performance the same thing? I was looking into a G-Force with their upgraded case & mainshaft along with upgraded shift forks... But it seems G-Force rates their transmissions lower than Astro.

 

[PUNISHER RACING]

Astro build them with G Forces parts in them

 

[FastGT94]

That's what I suspected, thanks.