The stock tranmisson has abeen a weak point in my race car for a while and most full on race transmissions are out of my budget range so I decided to try the relativly affordable t5 gearset option from GForce transmissions.

I picked up a used t5 transmisison, adapter from t5 to rotary bvell housing, and t5 yoke, from Jeff Kiesel. GForce took the transmission and installed their close ratio, straight cut, dog ring gear set.

Here is a link to GFroce t5 info:
http://gforcetransmissions.com/tran_gt-5.asp

With andy helping me with the gear ratios, the 2.46 kit was the best option along with the .82 5th.

Installing the t5 was not that difficult, here are the main issues:

shifter location
the t5 is about 5 to 6 inches more forward so that puts the shifter location in teh dash area, this is a race car so we can just cut the dash up, and I made a shifter extention as a temporary fix to the shifter location. Pics below. Idealy you would use a 'remote shifter' to keep the shift throw the same, similar to this: http://www.steeda.com/products/steed...ax_shifter.php , or you would mod the t5 sililar to this: http://enderw88.wordpress.com/2008/05/03/remote-shifter

t5 trans to rotary bellhousing
not really an issue, just buy an adapter, done. Pics below.

driveshaft
not really a big deal either, a local driveline place made me one in a day, for under $300. Pics below.

supporting the t5 (no ppf anymore)
this was a bit tricky, I made a makeshift bracket/bushing setup to get me by for now, but need to fab up a 'real' brace for the trans eventually. Pics below.

supporting the diff (no ppf anymore)
not a big deal, buy a banzai diff brace, done. Pics below.
note: I put bushing material between the diff brace and car chassy.

clutch disk
the GForce kit uses thier upgraded 26 spline input shaft, and this does not mate with the stock clutch disks, but I contacted ACT and they actually have a disk that is the stock FD diameter but mates to a 26 spline inputshaft. Pic and part number below.

trans sensors
Well, its a race car, so this was not an issue. For a street car you would need to do some work here if you want to keep the speedo, et. But its not a big deal, you get one of these for the speedo and you are done: http://store.summitracing.com/partde...part=dak-sgi-5

Link to the video of my first test of the trans, but sure to have the volume up high, the sound is the best part:
http://www.new.facebook.com/video/vi...?v=63326195166

And the pics:

The clutch disk and delrin rod I picked up to make the new shift handle:



The t5->rotary adpater:



The new drive shaft, next to stock one (stock is on top):



Pic of trans with adapter, shifter, and clutch disk attached:



Pic of shift area and trans tunnel cut:



Pic of t5 mounted and exhaust ipe in place so you can see the clearance:



Pic of the Banzi diff brace being test fit:



(more pics in next post)

 

Series of pics making a new shifter 'boot':








Series of pics making the shifter extention:







Series of pics of the temporary trans brace setup:







Pic of the shifter in place:

 

Congrats on your successful efforts. Looks great

 

Love the sound of flat cut gears.

 

thanks :-)

 

GOOGLE video link for those without facebook:
http://video.google.com/videoplay?do...42404832&hl=en

 

omfg ... love the sound

 

Looks and sounds killer! Is is full clutch-usage up and down or can you lift and shift clutchless on upshifts?

 

Whats the lifespan of a gear set like that? can you get a few seasons out of it before rebuilding it?

and, how much did it all cost when you were done

 

digging it man. after talking to you up and the track to all the perks of this tranny im gonna have to save my pennies and get one for the fc!!! how far off you figure gearing would be for those of us that arent running 17's... wondering if the gearset in trans would be correct and might have to adjust ring and pinion ratios to get it correct or what

 

Hi Damian,

just a few questions if you dont mind, did you have to alter or modify the input shaft to fitt into the eccentic bearing in engine or not, where did you get the adaptor plate made or where did you purchase it please.

I have checked out the G-Force gearset, not a bad price at all, did you have the 5th gear modification done to your box and did you upgrade the main shaft as listed on the g-force site.

Looks to be smooth and fast shifting, up & down, are you stabbing the clutch on down shift ??.

Cheers

 

if anyone is interested i have a t5 trans and adapter plate. All you would need is the Gforce gearset. I bought a gforce tranny instead so i no longer need it...

 

Damian,
What specific shortcomings of the factory gearbox does this overcome? power capacity/durability? Shifting speed? Ratio adjustment?

 

Will this fit in a street car without hacking up the interior? (making it look stock) My tranny is starting to make noises after the weekly abuse I give it on the track. This would be an awesome upgrade.

thewird

 

Great job Damian!

How much did it all set you back? BigAl hooked me up with a guy who sells rebuilt Jerico's from NASCAR cup cars for around $2500-3000 which seemed pretty damn cheap to me, but this looks like a great option too!

 

After hearing that trans your FD is now officially a RACE CAR NOW I must must slow my heart rate and meditate, I'll be on the track soon, breath in, breath out

Hey Damian,
Seems like a lot of compromising went into the setup. How much did this cost relative to the other options?

Keep a close eye on the diff brace. I bought a car a few years ago w/ a cracked PPF and I think the original owner remedied the crack w/ the brace but the brace broke after only about 250 miles of hard driving.

 

This car just continually evolves and always impresses.
Great job Damian.
What type of power can this handle?

 

The only remedy for a cracked PPF is a new one, a brace on a broken part is certainly is not the answer. Additionally it could not have been our brace considering we have only had it on the market for a little over a year.

However I would keep an eye on it since it was not designed as a differential support to replace the PPF, it was designed to aid in the stability of the OEM components.

 

just Awesome!!!

Congratulations !!!

 

All of the above!

 

Were you able to use the stock pilot barring and bushing? or did you have to go with something aftermarket? Or was the inputshaft possibly modified to accept the stock pilot barring

 

That sound so awesome... i love how solid it looks when shifting. Wish my T56 was that solid feeling.

I would strongly recommend looking into a different dif brace. The banzia unit is great but as mentioned, wasn't designed to be used alone. i think there are a few LS1 guys who tried that and ran into problems with just the banzia unit.

I would see if you can get one of these, looks like a pretty solid unit and it is chrome moly.

http://www.v8rx7forum.com/v8-rx7-tec...ace-mount.html

 

wow i need to do soem catchin up on this thread:

non-clutch upshofts, just ease off throttle and shift, easign off throttle will release the dog 'teath' from each other so you can shift, when u are on the gas, they actually pull towards each other

still clutch down shofts, listen to the video, you can hear me heal-toe blip still, but its MUCH faster now, like BOOM, BOOM, BOOM....no waiting on syncros to shift

 

>>Whats the lifespan of a gear set like that? can you get a few seasons out of it before rebuilding it?

Not sure yet, i will find out :-) It is rated for much higher power/tq cars (IE like 500 to 600 rwhp..500 tq cars) so if I 'use' it properly (dont wussy shoft, shift hard and cristp) then I would hope it should last a while. Upgraded straight cut gears, these are very strong, so that should not be an issue, and the t5 case is solid, its probably just a matter of how much i abuse the dogrings and when they will need to be touched up or replaced.

>>and, how much did it all cost when you were done

was the most affordable dogbox option i could find, most full dogring kits were in the 6K to 8K range and still used the stock trans case, and ful on race dogboxes can be from 6K to 26K depending on setup. Jerico makes some great dogboxes at relativly affordable prices, but with the gforce t5 setup, you can have a solid dogbox for around 3K depending on what you do. I did no upgrades really, just the base straight cut, dogring, close ratio setup. It already has upgraded everything in terms of gears, input shaft, et, et.

- used t5 case (they are all over, anywhere from $20 at junk yard, to $500 for a 'good' trans, btw you dont need a good trans, just the case, since all internals get replaced by the gforce gearset)

- rotary adapter (not sure exactly?? i got this in a groupo deal from jeff K, with the t5 trans and yoke, maybe $300 to $500)

- new driveshaft ($200 to $300)

- gforce gearset (2600ish if you have your own t5 for them to use)

- some other odds and ends, but that is about it for race car, more if you are tying to make it work with stock speedo, et

>>how far off you figure gearing would be for those of us that arent running 17's... wondering if the gearset in trans would be correct and might have to adjust ring and pinion ratios to get it correct or what

well thats a complex question, as it involves your powerband rpm range, et, et. But in anycase, its MUCH better than stock ratios :-) lol

>>just a few questions if you dont mind, did you have to alter or modify the input shaft to fitt into the eccentic bearing in engine or not, where did you get the adaptor plate made or where did you purchase it please.

gforce knew exactly what to do wit the input shaft to mate with a rotary engine, and it went in like butter :-) they knew the exact number to machine the input shaft pilot.

as i mentioned above, the adpter plate i got from jeff K with the t5 trans aswell. a few places sell an adapter to a t5, gforce may even make one.

>>I have checked out the G-Force gearset, not a bad price at all, did you have the 5th gear modification done to your box and did you upgrade the main shaft as listed on the g-force site.

i did not do any other extra upgrades (my car is not making crazy TQ or rwhp), and for fifth gear, i went with the best ratio they had for me, a .82. %th gear could not be dogring from what i was told, so u do have to shift 5th (as you see in the video).

>>Looks to be smooth and fast shifting, up & down, are you stabbing the clutch on down shift ??.

stabbing? i dont stab anything on the car LOL .... its called heal-toe, video of old trans with footwork footage: http://videobookmark.net/www/Windows...-2007_test.wmv

>>Damian,What specific shortcomings of the factory gearbox does this overcome? power capacity/durability? Shifting speed? Ratio adjustment?

specific shortcoming, u alrady said it, the factory gearbox...its the 'specific shortcoming' :-)...., its all the things you just mentioned, I have gone through 4 stock trans in last 3 ro 4 years... mainly sheering 3rd gear teeth off DURIGN DECELERATION...one , me and Andy (1 alp co-pilot) blew up all the syncros on during 1 lap lol...anyway, so its exaclty what you said: power capacity/durability? Shifting speed? Ratio adjustment?....all those things.

>>Will this fit in a street car without hacking up the interior? (making it look stock) My tranny is starting to make noises after the weekly abuse I give it on the track. This would be an awesome upgrade.

with some work you could do it, but would have to modify the t5 shifting mechanism so that its farther back, not a remote shifter, but literally extend the shifter rod to a shifter farther back, then you would not have to cut up the trans tunnle or dash at all.

>>How much did it all set you back? BigAl hooked me up with a guy who sells rebuilt Jerico's from NASCAR cup cars for around $2500-3000 which seemed pretty damn cheap to me, but this looks like a great option too!

yes, those are cheap for jericos, but arnt they only 4speed? i get 5 gears, and REVERSE!!!! thank GOD for reverse!!! see above for how much it cost me.

>>After hearing that trans your FD is now officially a RACE CAR NOW I must must slow my heart rate and meditate, I'll be on the track soon, breath in, breath out

FRITZ!!!! holy **** you need to drive this thing, you would really love it, its literally does transform the car's driving experience from a hopped up street car to a full on race car, its my favorite upgrade :-)

>>This car just continually evolves and always impresses. Great job Damian.
What type of power can this handle?

thanks :-) ... and talk to gforce abotu the max power/tq numbers, but they estimate int eh 500 tq range (500 to 600 rwhp ish)... obvisouly for my car this was a large buffer, and that is EXACTLY what I wanted, a nice buffer so the trans is no longer a weak point in the race car.

>>However I would keep an eye on it since it was not designed as a differential support to replace the PPF, it was designed to aid in the stability of the OEM components.

yes, ill keep a close eye on it, this was really to get it up and running, my plan was to eventually make a new full on support for the diff, possibly tiedinto the rear subframe. I think a big part of any braces craking or failing, is lack of bushings, thus I tend to bushing braces instead of directly connecting them to the chassy. Even a stiff bushign material will absorb some drivetrain shock, and you want it to go in teh bushing, not the parts.rr

>>I would strongly recommend looking into a different dif brace. The banzia unit is great but as mentioned, wasn't designed to be used alone. i think there are a few LS1 guys who tried that and ran into problems with just the banzia unit. I would see if you can get one of these, looks like a pretty solid unit and it is chrome moly.

thanks for the link, i will look into it, it may be an easy solution to hold the diff up :-)

 

That video is straight sex. Love it.