http://speed-eng.com/store/index.php...2_61_2018_2021

The complete conversion kit is $3,200. But if you factor in the cost of a converter and install (assuming the buyer can't install himself) you are in the 4-5K range.

That transmission is good for 700HP. For the real serious power guys they could spend $3500 on the built transmission alone. Then the whole conversion price could easily exceed $5,000 (again assuming you have to pay for the install).

 

I believe that it's good for way more than 700HP. Parish uses that trans on his truck which is over 1000HP if I'm not mistaken. Also you need a convertor for the 4L80E since you can't use a 4L60E convertor. So even if you could do the install yourself, you're still looking at 4K minimum. Very pricey..........

 

I'm just going by what they advertise. I know you can't reuse the 4L60E converter which is why I mentioned the fact that you have to factor in the converter cost on top of that conversion kit price.

I am personally considering that kit for the the 08 racing season. I figure that kit with a converter and install will run me about $4500. Very pricey indeed! But people spend 15-25K on complete motor/suspension/power adder setups. So spending another $4500 on a stout transmission setup that will allow you to enjoy OD & electronically controlled shifts (in a 9 second car) suddenly doesn't seem quite so outrageous. At least not to me.

For a street/strip car in the 9's this is my favorite option. For a strip only car I prefer the TH400 or Powerglide.

 

I don't know about the other guys, but my 9 second car requires a 3.00 rear gear due to the 146 mph trap speed and 6400 rpm max. That's pretty tolerable without OD in a street car.

 

I'm looking to keep my 3.23's and raise my shiftpoint to 6800. I'm sure a TH350/400 will be more then tolerable on the street for my setup. But with the 4L80E I can have the added bonus of OD for all the highway driving I do. I'm not expecting any more then 135 traps though.

Sounds like a monster setup you got there

 

Yeah I knew that you were including the cost of the convertor but others reading may not know that. I hear you about the cost of the trans for a 9 second ride but there are alternatives out there, just have to find a reputable builder.

There's a member on here running 145mph traps with his built 4L60E, you can find him on the quickest ET list. That car may be a vette but 145mph traps is more than enough for me

 

That's insane. His car must be pretty light to make any 4L60E survive more then a few passes with that much power. I wonder how high he spins that motor? I heard keeping the weight,revs & temps down helps the longevity of those transmissions.

But I personally wouldn't trust a 4L60E once 130+ traps are attained. At least not for a car over 3200 pounds and reving to 6800 or higher.

 

I'll post his screenname...gimme a few minutes.

 

That was fast

https://ls1tech.com/forums/member.php?u=47044

149mph

 

His Vette is bad ***. I've also heard good things about RPM's transmissions. But I'm still not sold on the 4L60E being a solid transmission for 9 second cars. If there were a dozen guys all doing it for multiple seasons with success then I would jump onboard in a heartbeat. But I consider his luck/success as the exception and not the rule.

 

I agree, I wouldn't use it as a "9 second multiple race season" trans. Good for daily driving though

 

Well guy my 4L60E has lost 3rd and 4th gear twice so now ive decided to go with the Turbo 350. My dad has ran his cars to a 1.37 short time with this tranny so i think it will do just fine for my TA. My 4L60E is fully built but ill prob just sale it with the torque converter and all and just buy the 350 and not worry bout it anymore.

Quick question will i need the short tail shaft or the long one?

 

With all this talk...... I can only say one thing: How many people do you hear abotu breaking/having problems with 4l60 transmissions? How many people do you hear abotu having the same problems with a th400?


If you have modded a car to the point that the 4l60 is not holding up even after a good performance build, you are overpowering/overspinning the tranny, and that's all there is to it.

If highway use is a concern, I can only advise to leave a 3.42 gear in the rear, get some 28 inch tall radials to run on the street, and get a lockup converter setup for the th400. Do that and you'll most likly be o.k.

I have a th400 in my car, and with stock size street tires on , with 4.10's and a converter that will flash to about 5800 I'm at 3400 going 55. A set of 28 inch tall tires gets me to about 3000 at 55. I knwo most people don't want to cruise at 55 on the highway, trailer trucks will pass you going up hills LOL, but noone gets a speeding ticket going 55 on the highway either, so look at it as a wy to help prevent uselsess tickets.... that's what I do.


And if you are doing a th400 swap, get a csr carbon fiber tranny scattershield, it fits fine, and if it were to ever come apart, your feet and car will thank you for spending the 250 bucks they are new in the summit catalog.

 

Since the thread is started again, id say a th400, love mine got rmvb and t brake.

 

What rear gear could I run with my current setup that would let me run okay highway RPMs, but still not kill track times with a 3400 stall, if I use a TH400 or even TH350?

 

I think a 3.73 would work

 

70mph with a TH400 or TH350 and a 3.73? Sounds a little steep to me.

 

Well it depends where you are at, back in Wisconsin, traffic is not normally cruising at 70, but out here in Cali you would be in the slow lane, its a happy medium.

 

with 4.10's, th400 and a 5800 converter, 55 is 3500 rpm.

3.73 would put me to about 3200. Converter will have alot to do with it, if you have a loose n/a type converter like what I'm running, you will be spinning about 800 more rpm then you would with a stick car in 4th gear no matter what, it's the nature of the converter, just the way it is.

But, you put a tight converter in it so it drives around nice, and it will run like crap at the track. Bottom line, you want to go fast you're gonna have to deal with it, or just settle and go slower. There is no magic bullet that will be a bulletproof tranny and let you cruise at 70 at 1800 rpm... it's just not gonna happen.


Like I've said earlier, if you are making enough power to chew up 4ljunkies quickly, then you probably shouldn't be daily driving the car anyway.. and need another car, or even better a truck with a trailer so you can bring the car to the track too while you are at it, rather then driving it there.

 

I have a 4l60E built by Century in houston.It`s there Stage 3 build. I push around 530-540rwhp N/A and another 200 with my 200 shot. I have a window switch so I don`t spray threw shifts. I spin to 6600rpms. Pills are 3200-6400! Century has said theirs hold alittle over 700 plus at the wheels. What helps with mine is I don`t spray threw shifts and spin over 6700rpms. Got a cooler and all! I had a H/C with 150 shot before with there stage 1 build and never had any problems. If and when mine goes I will put a 4l80E so I can keep my OD. But so far no problems. Century has a reputation of build tough trannies! Hope mine is one of them!