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Tremec T5 on a Twin cam?

PostPosted: Sat Dec 22, 2018 6:16 pm
by hbferrariguy123
Hello,
Does anyone have any experience with using a Tremec T5 transmission with their twin cam? I've found that RWD Motorsports in the UK are manufacturing a bell housing that allows the transmission to bolt to the engine without further modifications other then the obvious clutch, shifter and mounts.
If you have some info or experience please let me know. I also need some help in choosing the correct transmission considering the different gear ratios used through out the years.
Thanks in advance!

Re: Tremec T5 on a Twin cam?

PostPosted: Sun Dec 23, 2018 4:32 pm
by bitsobrits
I'm rebuilding an Elan for which I converted it to a T5z (new) gearbox with a .80 5th gear. I was unable to find a suitably short input shaft, so had mine machined down to suit. Also the front bearing retainer on the gearbox needed machining to fit the shorter input shaft and the outer diameter reduced to fit into the bell housing. A modified block to bell housing plate and clutch inspection cover is needed. Then you will need to fabricate a custom trans mount (fairly easy), a different slip yoke on the modified drive shaft (early 6 cylinder Mustang works), and the chassis will need some surgery to clear the shifter housing part of the gearbox. Really best done with the body off. The referenced bell housing's two starter mounting ears (provision for mounting the starter on either side) likely means a slight tweak of exhaust pipe routing. Starter mounting is 3 bolt btw, not 2 bolt. And of course with no provision for the standard clutch actuation hardware a change to a concentric type of slave cylinder is required.

Other than that it's a direct bolt-in, as you say.

Re: Tremec T5 on a Twin cam?

PostPosted: Sun Dec 23, 2018 4:45 pm
by gjz30075
Steve, do you put the slip yoke from the eary 6 cyl Mustang on the proper Elan prop shaft?

Or, do you modify the diff end ?

Re: Tremec T5 on a Twin cam?

PostPosted: Sun Dec 23, 2018 10:03 pm
by hbferrariguy123
Steve,
Thanks for your info. It looks like there's plenty of modifications needed to make it all fit together properly. The RWD Motorsports web site, which I haven't thoroughly read shows different clutches and parts available to help complete the conversion. Some more research is necessary before I begin.
As far as the chassis modifications, the engine and transmission aren't going back into an Elan instead I'm putting it my 1949 MG TC. I figure it'll make for a fun ride! (The insurance company declared the Elan a total loss.)

Re: Tremec T5 on a Twin cam?

PostPosted: Sun Dec 23, 2018 11:39 pm
by Jentwistle3
Brakes too, I hope!
JE

Re: Tremec T5 on a Twin cam?

PostPosted: Sun Dec 23, 2018 11:50 pm
by hbferrariguy123
I haven't started my MG TC project yet as I just finished a '78 Lotus Esprit which I put a 215ci Buick engine in. Now that that car is done and for sale I'm just getting my ducks lined up for the MG project. Yes, I'm looking at upgrading the brakes along with strengthening chassis by fabricating boxing plates and possibly additional or increased in size cross members. Steering and suspension will also be considered. Lots of work but lots of fun!

Re: Tremec T5 on a Twin cam?

PostPosted: Mon Dec 24, 2018 2:16 am
by bitsobrits
gjz30075 wrote:Steve, do you put the slip yoke from the eary 6 cyl Mustang on the proper Elan prop shaft?

Or, do you modify the diff end ?



I used the original prop shaft, and had a local shop weld on a new front yoke compatible with the Mustang slip yoke. While the Mustang 6 cylinder yoke has a u-joint similar in size to the Elan, it has C clips on the inside of the universal joint bearing cups, unlike the Elan which has the clip on the outside of the cups.

Re: Tremec T5 on a Twin cam?

PostPosted: Thu Dec 27, 2018 7:02 pm
by TomR
I have a T5 in my Cosworth BDG-engine Elan S4. If you search you'll find a lot of detailed information on the modifications I applied, although there are several options for some aspects. The biggest issue was the bellhousing which may no longer be a problem. I definitely takes some work: turning down the input shaft, concentric clutch slave, new driveshaft, figuring out how to get the speedo to work (I'm now using a GPS-based Smiths Cobra speedo to avoid the mods required to get either a mechanical or electrical transmission signal), but the low weight, high strength, and gear ratios available for the T5 are huge benefits.

TomR

Re: Tremec T5 on a Twin cam?

PostPosted: Thu Dec 27, 2018 8:42 pm
by hbferrariguy123
TomR, thanks so much for your info and guidance towards your modifications. I'll search for them and will apply them on my project.
How did you decide on your choice of transmission? Vehicle weight, hp...?
Thanks, Lou

Re: Tremec T5 on a Twin cam?

PostPosted: Fri Dec 28, 2018 9:55 am
by bigvalvehead
This page will give you all the ratios and where to find them
Toms info is really good.
You will need the S10 shifter position.

Cheers
Dave

http://www.britishv8.org/articles/borg- ... d-tags.htm

Re: Tremec T5 on a Twin cam?

PostPosted: Fri Dec 28, 2018 1:52 pm
by gus
basically mustang or camaro/firebird v8[not v6] for the ratios, and an S10 chevy truck/suv for the tail housing[shifter position]

Re: Tremec T5 on a Twin cam?

PostPosted: Fri Dec 28, 2018 4:05 pm
by nomad
Around 1970 I was in the Navy based out of SF. At that time there was a TC running around with a SBC in it. You could watch the frame flex at a light. At the time I owned a TC and considered that car to be an abomination. There are a lot of other things you will need to change in your project such as the 19" wheels. Hope you can find a better home for the twink. I have no problem with most swaps but I'm afraid I still have a soft spot for the original TC. Just too much of a change of character for that car.

Kurt

Re: Tremec T5 on a Twin cam?

PostPosted: Mon Dec 31, 2018 9:00 am
by rcfurse
There was talk that someone was going to do a bellhousing to allow the MX5/Miata 6 speed to fit. Did this go anywhere?

Re: Tremec T5 on a Twin cam?

PostPosted: Mon Dec 31, 2018 4:43 pm
by The Veg
rcfurse wrote:There was talk that someone was going to do a bellhousing to allow the MX5/Miata 6 speed to fit. Did this go anywhere?


I've heard mention of that. Would be wonderful if it came to be! My foggy memory says that somebody here mentioned that the project disappeared in the aftermath of the big recession.

Re: Tremec T5 on a Twin cam?

PostPosted: Mon Dec 31, 2018 4:55 pm
by prezoom
Try looking a turbosport.com. In the Technical Section, there is a thread on gearboxes. There is a fellow that makes adapters for the MX5/Miata and the RX8 units. Actually two who make the adapters. One does not have the best reputation. Most seem to choose the RX8 adapter because it mounts the gearbox straight up, rather than at an angle like the MX5/Miata. Not badly priced at about 110 pounds. Lots of information on the installation to the small Ford block, plus others, i.e., Zetec, Duratech, etc. Nice thing about the RX8 units is their price, dirt cheap.