anyone have any info on converting a 87 vette with 700R4 to a 4L80E. My problem areas will be the tail shaft housing where the torque tube connects to the tranny. Because the tranny is longer ..some under carrage work needs to be done...along with torque tube mods and driveshaft mods. I will also need a stand alone computer to run the system. I have the trans allready...just wondering if anyone has tried this before...this is the the tranny I want to use..no powerglides...etc......If any one has pics or info..please feel free to emial me or send me info.....

 

Yes, I have been considering this same swap as I have paid to rebuild too many 700r4's.

 

How about adding a modified convertible X brace to act as the rear trans mount and c-channel mount.

Would also stiffen the car a little.

 

Just got my 4L80E trans...going to have it rebuilt. The X brace is a good thought...will look into that. I will probably machine an adapter to go between the area where the stock 4L80 tailshaft housing goes that will except my standard 700R4 tail shaft housing...will have to machine my torque tube (make it shorter)..and also have to use the bigger yoke from the 4L80 trans welded to a shorter drive shaft(stock shaft. When this set up is done..it will be heacy duty...and I will have full cockpit control of all gear shift points and firmness.... keep upwith the info/ideas....thanks

 

If your going through the work of upgrading your tranny to 4L60E, Why not upgrade to a LT-1 or LT4 and have the best of both worlds. The LT1 is an awesome engine. This would take care of the computer problem and allow to modify your shift points much easier.
Dan

 

First of all....we are not talking about a 4L60E....We are talking about a 4L80E...which is a much much stronger trans than the 60. The 4L60E is the same as the 700R4...except electronic.....niether the 700R4 or 4L60E can handle the HP/TQ I am making. I have a L98 ....Would not trade it for an LT1....they are the same motors....with a few changes..still a small block chevy....both can make same HP.......If there is anyone with any info on the 4L80E....please let me know..I will try to keep everyone posted on this conversion..thanks for the replys....Tom ....when this conversion is done I think it will spark alot of interest...for those people who keep blowing there 700,s etc...

 

oops-Maybe I missed the 80. Your currently running a 27 spline. I beleive the 4L80E has a 32 spline. A new 32 slip-yoke will be needed. The 4L80e is behemoth, weighing at 225 lbs. w/ the converter. The tranny is 31 inches long overall. To swap in the 4L80E, the driveshaft will need tobe shortened 3.25". Most guys swap over to a 6 speed will dealing with the kind of power your talking about. The LT1 is a very different engiine. It's built for HP. The heads are much better flowing, compression is more, bigger cam, and it has a superior cooling system. If I put the same money into an LT1 as you put into a L98, The LT1 will still be superior. Good luck! I hope it works out for you.

 

The LT1 is a fine engine from the factory in stock form. However It has its limits. For example, with a 3.875 and .060 bore (MAX), Your looking at only a 401ci motor. If you trying to build a big cube small block, thats it. Not like a 427ci or a 434ci which you can build all day in the pre87 style short block. The LT1 and LT4 are great motors and emission friendly, however the aftermarket companies haven't completely jumped on board to allow us gear heads to build big displacement small blocks.
The Revearse cooling is a great settup for more efficient cooling of the cylinder and chamber which allow one to creap up on compression while still running 93 octane.
Overall both settups will yield good results (all relative), but the pre 87 has been around much longer and has a more versital market.

Regards
John
:cheers:

 

Switching to a stick was an option...but the 4L80E without a doubt will handle what a standard trans will horsepower wise. It will also soften the load the rear end takes..those Dana44's are not indestructable. Doing this conversion will be time consuming..but shortening the torque tube a drive shaft is the easy part...the hard part will be keeping the front tires on the ground with my "L98"....sorry LT 1 owners..you will always be behind me..so you will never see this...just kidding.....keep the info coming...everyday I learn something new..Thanks..OH...thanks for the support bowtie....I heard you were looking to switch to a auto trans??????...still havent mastered how to use that stick shift.....

 

The Bottom line with the ZF, Tom is mearly this. The auto is going to 60ft better, going to ET better, and is going to play less havic on my Dana. Oh and also, regarding my shifting! If I shifted it like a stick should be Shifted, I would splatter this German made housing into pieces. And I dont have the $$ everyyear for a rebuild. So whats a couple of tenths amoung friends. PS also remember I am 11.90's, and get 25mpg with my 4:09. 6th is 0.5:1 you can only dream about that with your auto. :nopity

;)
Regards
John

 

In the GM Performance Parts catalog. Pg. 169 they list a transmission controller (12497316) for installing 4L60 and 4L80 in earlier cars. Says it programable etc. Hope this helps.

 

Have you thought about using a Th350 or 400 with a Gear vendors o/d. The od unit is rated a 1500hp full throttle shifts into the o/d unit so I do not think you will break it. This is what the automatic Callaway cars used so you can go to the Gear Vendors web page and they should have the adapter for the corvette. Oh yea it also makes the Th350/400 a 6spd auto.

 

Tomulrich,
Please do keep us posted on progress here. I am curious as to how you do with tunnel clearance too. I have heard of people getting a 4L80E in there, but never talked to anyone that did. My 4L60E amazes me at how well it does holding up once I got down the right way to build them, but it is still a big limiting factor, I fear adding power at this point and don't want to give up the over drive.
Also, can you get a lower 1st in a 4L80 as you can in the TH's?

jabbott, one advantage of the 4L80 over the TH400 with od box is the locking converter. That comes in handy on the street. You can get away with a looser converter without the added RPMs or heat.

If I swap over to a 4L80 it will be time to start looking at super/chargers or big blocks :D

 

Good luck at trying to get it to fit.
I tried putting a 4L80E in my '94 and there was no room on the passenger side tunnel. There is no room to clear for the exhaust without cutting up the tunnel-something I didn't want to do. I'll be interested to hear someone's horror storey.

 

I will definately have to do some tunnel work to get tht trans and exhaust to fit. I will also have to shorten the drive shaft loop and drive shaft. It is not going to be an easy job. It is all fiberglass work to the under side of the tunnel. The gear venders overdirve to me adds tooo much legnth onto the existing trans..still have to do tunnel/loop and drive shaft work. You dont however get the lock up, or the best advantage..having full control of every gear shift point and every gear shift firmness...Converting to this transmission is like going from a carb to a fuel injected system....As far as the gear difference it will be a plus...the 700R4/4L60E...is great in first gear.(for the short second it is there,,,then the gear spread is too much...can bog down when going into 2nd gear. With the 4L80E..my HP will be unlimited and I can even go to 4:09 :1 gears ...in an automatic...It will be a great conversion..I think You will see more in the future...I am 3/4 of the way finished designing and producing the bracket at the end of the 4L80E tailshaft housing that will connect the torque tube to the rear. Next will be some cutting and remolding of the under side to the tunnel for clearance.....oh..the unit will not be controlled by the GM performance parts controller..also same as TCI controller. I chose to go with a controller called Compushift,does all the GM one does except it needs no lap top...it has a liquid crystal display that allows you to adjust everything from the dash....even gives you HP reading...check it out here is the site... http://www.hgmelectronics.com/....keep the info comming..it will be a nice clean job when it is done..no more worrying about breaking transmissions....allready purchased a 2800 10.5 torque converter fro Pro torque...900.00 whew....1500.00 for the controller..whew........it will be nice.. :smash:

 

I will need to do some tunnel mods to get the unit to fit ..cut and remold... I thought about the gear vender unit,,makes the tranny too long..still have to go extensive mods to tunnel/drive shaft etc.. and you wont have full control of the shifts.....this unit will be a great conversion....I went with a compushift control unit..http://www.hgmelectronics.com/. I am 3/4 of the way done designing and producing the bracket for the 4L80 tailshaft housing that will hold the torque tube..pics will soon be on Bowtie8's web site(i hope he will let me)...next is the tunnelmods. I bought a 2800 stall speed converter 10.5 from Pro torque.....900.00, computer 1500.00 expensive but It will be like the difference between a carb and fuel injection...Will keep eveyone posted......

 

Yes, you can get a lower first gear in the 4L80-E, they are the same as the TH400 except they have some sort of electronic sensor in them. I hear that installing the sensor only requires driliing a small hole .


[Modified by dsagers, 4:38 PM 9/6/2001]

 

FrankD.

Did you actually get the 4L80E mounted to the engine?.....did the trans physically fit other than the drive shaft and torque tube being to long. .....Was the main problem the exhaust clearance on the passenger side?.....I would like to talk to you more see how far you have gone with this..if you wouldn't mind emailing me your Phone number.....TMO26@aol.com.....thanks....I f anyone else has actually mounted the trans to the engine....leave me your number on my email...TMO26@aol.com...Thanks Tom...

 

TOMULRICH, the 78 and up TH 350 had a locking converter. The G/V unit is one awesome unit. You do not hear much about it because they do not do much advertising. However there are allot of Gas cars "Dragsters" not Top Fuel, that have Power glides that use that unit to make them four speeds. I can't say enough about it.