Thread: Gemini dual chain or 7/8" single?

The stock trans on my car is slipping pretty bad so I am currently researching a new trans option. My best bet seems to be the TEP route, so I shot Dave an email in regards to what trans setup would be best for me, etc. His response was that their stage 1 performance trans with an upgraded input shaft would be fine for my current mods (see sig). He implied that a new stock dual Gemini chain would be fine for my mod level and that it would actually last longer than the upgraded 7/8" single chain under normal use. He said the 7/8" chain would be ideal if I were making 330+whp and wanting to making frequent passes at the track running sticky tires. Sooo, what should I do? I do not intend to race the car, but I may hit the track someday just to see what it runs. Also, I plan on converting to E85 when it becomes more available hence creating more power. Should I listen to TEP and just run a dual chain or spend the extra coin on the upgraded 7/8"? Would a 7/8" chain last a long while?

Should I listen to TEP

Yes. He's a walking 4t65e bible, I'm amazed at how much this guy knows. The new dual chain he uses is a hardened version that GM developed for the 303hp grand prix GXP. It has its limitations, but looking at your mods I'd say you'd be fine with it.

Has anyone even broken a GXP chain set yet?

7/8" stretches on hard launches, ask if the V8's do as well. Heck, you were there when I noticed the last 7/8" stretch and again reluctor was torn off. It comes down to normal driving. The V8 chains are very good and hold a lot of power, Dave would be the one to know best on if 7/8" are stronger than V8 etc.

You can destroy either chain setup by driving the way I did. Look at the way Dan and Nick drive.. sure seems the rolling race is a lot easier on the chains. A few track passes shouldn't hurt either chain setup though.

I would go with Dave's recommendation and run the stock chain.

Originally Posted by BillBoost37

Heck, you were there when I noticed the last 7/8" stretch and again reluctor was torn off.

Haha I remember that night. Bonnie hits the 130 mph mark twice then poof.

I'm on the fence on this one....If it were my decision I'd really have to ask myself how serious you were about tracking the car and running E85. Next big question would be are you going to be using drag radial or slicks...

I have a very similar setup to yours and on E85 without and IC and without P&P head I put down 330whp/400wtq. When talking with Dave at TEP I had plans of pushing my setup to the 350whp and that's when he led me towards running the 7/8" setup.

That was probably under 2000 miles on a new chain and gearset. Chain stretched enough and was dragging in the case, the feeling/noise was the reluctor after it tore off the gearset. I've seen your driving and I think you'll be ok either way.

Originally Posted by BillBoost37

That was probably under 2000 miles on a new chain and gearset. Chain stretched enough and was dragging in the case, the feeling/noise was the reluctor after it tore off the gearset. I've seen your driving and I think you'll be ok either way.

If you don't in any way shape or form drive like Bill run the dual gemini setup.

Chris... on the E85, it's a great idea, I have not heard anything on expansion in our area. Trying to find it is difficult around here and unless you've found info about it coming in soon. I can't foresee it happening in the next 2 years.

Originally Posted by BillBoost37

Chris... on the E85, it's a great idea, I have not heard anything on expansion in our area. Trying to find it is difficult around here and unless you've found info about it coming in soon. I can't foresee it happening in the next 2 years.

If only I still lived in Holyoke.. Racing mart about 15 min away in Northampton carries it.