CUTLASS Trans for full LSA swap?

[JustBoostin]

Recently picked up an LSA for my 84 Cutlass. Plan is for this to be a driver, automatic, pump gas, cammed, 15-18 lbs of boost.

So, I’m wondering, what trans? I’m told 4L80’s are heavy, both physically and rotational weight. I hear 4L65’s are another option?

 

[ck80]

If by lsa you mean the 6.2l,.and you're upping it onto a higher boost and power level, IMO 4l80 is a better choice than 4l65

Side by side tests ondyno pre and post swap from a 65 to 80 trans showed a 15hp difference in losses between the two.

 

[JustBoostin]

If by lsa you mean the 6.2l,.and you're upping it onto a higher boost and power level, IMO 4l80 is a better choice than 4l65

Side by side tests ondyno pre and post swap from a 65 to 80 trans showed a 15hp difference in losses between the two.

That’s good info to know.

yes, 6.2 full aluminum

 

[64nailhead]

4L80 or TH400 depending on the application.

TH400 is just as tough and much more budget friendly for the trans, converter and non-electronic. A 3 speed is viable with the correct, quality converter, proper gearing and 600hp.

 

[JustBoostin]

4L80 or TH400 depending on the application.

TH400 is just as tough and much more budget friendly for the trans, converter and non-electronic. A 3 speed is viable with the correct, quality converter, proper gearing and 600hp.

Yes, I should mention that I do want a 4 speed. Specially with the engine already being computer controlled, I’d stay with an electric trans.

still need to dig but does Holley Terminator have trans control options?

 

[83StreetMachine]

I agree with ck80, With that engine with boost, 4l80 and you'll never touch it again.

At your power level and being a street car you'll never notice the difference in weight and parasitic loss.

You will be MFing yourself when you find yourself under there pulling the inferior trans when it goes up in smoke.

Do it once

 

[olds307 and 403]

You will be sorry if you run a 4L60,65,70E trans. They are not a strong trans, no matter who builds them. The 4L80E with minor mods can take 600+ hp. There is a reason they are heavy, strength. Basically a TH400 with a lock up torque converter and .75 OD gear added on.

 

[motorheadmike]

cammed, 15-18 lbs of boost.

What is that supposed to equate to in terms of power? Once you know that your transmission options will be revealed to you.

 

[64nailhead]

Answer Mike's question in previous post. If unknown, then say unknown.

Yes, I should mention that I do want a 4 speed. Specially with the engine already being computer controlled, I’d stay with an electric trans.

still need to dig but does Holley Terminator have trans control options?

Yes, a Terminator X Max will run both the motor and trans - I have one in my car, but I have DBC where I would assume you have DBW. You need to order the appropriate kit for your injectors and TB. I do assume that you will be running different injectors if you're aiming at 18psi.

I was only trying to point out that for something other than a car that will see hour+ long drives that a TH400 will work just fine. I.e. if you run a 27" tire and run a 3.08 or 3.23 gear, then the TH400 will work just fine. Remeber that you don't need 3.73 or 4.10 gears to turn a tire into smoke with an LSA - no spool up time required.

The 4L80 is a great choice though, but just more expensive for converter, substantially more for a converter.

 

[Northernregal]

Yes, I should mention that I do want a 4 speed. Specially with the engine already being computer controlled, I’d stay with an electric trans.

still need to dig but does Holley Terminator have trans control options?

Will you be using an aftermarket ECU or the factory LSA ECU? Depending on the year you could use a 6L80e with the factory ECU.

Otherwise you have one choice. 4L80e.