Thread: 4t80E trans swap

New holes cnc drilled and washers custom made for the right height and tig welded to keep the balance. We added weight back too

ahh i see sorta a hybrid combining the best points of both the W and G/H body mountings.

fyi most cars with those mounts (g/h/c/b body) also have a hydraulic damper next to the front mount to actually dampen the rocking. but since you have the uppers then your all good lol. i hate the W body uppers....the tq shouldnt be going to one of the most flexible parts of our chassis....that front core support can move alot just with a little brake tqing....im still curious how much it moves when getting into some big power.

dear god why did you weld those washers? please run a dial ind around the edge...those flexpplates are never straight from the factory so id suggest double checking with the additional welds possibly distorting it further

i just used the reduced head arp bolts, no washers, ours mated up flush, i only had to use washers with the 700r4 in the waGN but thats a different animal

the 442 has two billet meziere flex's so i think we'll be fine with just the reduced head arp bolts from the thicker web.

i have a 3.71, two 3.48 and one 3.11 FDR differential planet sets so far, initially we think we are gonna go 3.71 in the back and 3.48 up front...im hoping he will see the merits of just using the rear powerplant as the primary and that way the front can focus on the mid and topend, without having to haul around all that weight.
i had a lot of part breakdowns etc on the dhp site....shame its all gone but iirc you should have the 52 tooth sun gear if its the 3.11

also deburr and cleanup the sheared/punched window opening on the flexplates the next time they are out... those buggers are breaking from the edges of the sheared openings. an old magnet and grinding filings will point out any cracks that have started, though the sharpie test works too if they are big enough (look for a thin line to stay "wet" as the ink dries around it)

are you just doing the angle iron engine to diff brace? you have any problems relocating the knock sensor to the upper block register/boss?

Originally Posted by Turbocharged400sbc

ahh i see sorta a hybrid combining the best points of both the W and G/H body mountings.

fyi most cars with those mounts (g/h/c/b body) also have a hydraulic damper next to the front mount to actually dampen the rocking. but since you have the uppers then your all good lol. i hate the W body uppers....the tq shouldnt be going to one of the most flexible parts of our chassis....that front core support can move alot just with a little brake tqing....im still curious how much it moves when getting into some big power.

dear god why did you weld those washers? please run a dial ind around the edge...those flexpplates are never straight from the factory so id suggest double checking with the additional welds possibly distorting it further

i just used the reduced head arp bolts, no washers, ours mated up flush, i only had to use washers with the 700r4 in the waGN but thats a different animal

the 442 has two billet meziere flex's so i think we'll be fine with just the reduced head arp bolts from the thicker web.

i have a 3.71, two 3.48 and one 3.11 FDR differential planet sets so far, initially we think we are gonna go 3.71 in the back and 3.48 up front...im hoping he will see the merits of just using the rear powerplant as the primary and that way the front can focus on the mid and topend, without having to haul around all that weight.
i had a lot of part breakdowns etc on the dhp site....shame its all gone but iirc you should have the 52 tooth sun gear if its the 3.11

also deburr and cleanup the sheared/punched window opening on the flexplates the next time they are out... those buggers are breaking from the edges of the sheared openings. an old magnet and grinding filings will point out any cracks that have started, though the sharpie test works too if they are big enough (look for a thin line to stay "wet" as the ink dries around it)

are you just doing the angle iron engine to diff brace? you have any problems relocating the knock sensor to the upper block register/boss?

I didn't relocate the knock sensor yet. I was thinking of going with only the front. I will have to take a look at that.

As for the brace I did it the easy way but it should be strong. 1/4 plate cut to fit the countour of the factory engine mount tig welded to it. That plate is bolted to the diff

Speakling of which do I really need to relocate. Does the ECU read the knock sensor independantly ?
I know the front banks are more prone to knock especially with the crappy stock front manifold.

If I do need to relocate where would be a good spot that is proven not to cause to much harmonics to be picked up ?

BTW it's running and driving but we have to finalize a few connections to go test. can't wait to do a 1st gear launch on the rear engine.
I will keep 2nd gear launch for the front engine to help it get some traction.

With the small turbo quick spool 2nd gear launch on the front engine
With the big turbo slow spool 1st gear rear engine launch it should be easier to get good 60 foots than before.

knock occurs on the cylinder that has the worst breathing or an issue, your turbo so the pressure differential makes the front manifold flow issue no where near as likely, in fact my evidence shows that cyl 4 is likely to be the one to detonate from oil loading and 1/2 from the blower discharge directed right at the ports, our turbo car is 5&6.
the knock sensors monitor each bank and from what i can see aside from diagnostic purposes (faults on each bank) it seems to weight each bank equally. bin file kr settings have changed a bit over the years but i couldnt tell you if killing the code for the rear bank will affect the accuracy.

we ran the riv with it in the rear passenger side block register near the head deck, drill and tap to 1/4npt.

i think your gonna wanna swap setups.

low/midrange out back, mid/topend power out front.

btw did you find out the 80e tq converter bolt circle dia?

Moderator rule #1, move threads w/o redirect and see if people can still find them.

To the correct new section.

1.5 dont use roloc discs in the engine....

2.0.. take a bizzilllion hours to clean it without.

4t80e swap is a total success...

It was a nightmare to get it to fit and make the motor mounts etc...
But it already help up better than two 4t65s I broke in short time on the rear engine.
First 4t65 was the chains the snapped. The other was the input shaft.
The trans is putting a lot of power down and doesn't seem to slip as much as my 4t65 when it was working.

I had to use an Aurora 4.0 axle on the driver side and stock Deville passenger axle as shown in other 4t80e threads, that was all true.

For controlling the trans manually I only needed to push/pull switches to easily shift all the gears in the trans at full pressure. Not good for a daily but for a race car it works.
For those wanting an automatic shift there are boxes available and you can make the stock PCM work as shown by Turbocharged400sbc.

The stock shifter worked with the trans although we had to make a stopper to prevent the cable from popping on the shift arm on the trans.
Anyone running a turbo kit will likely need to modify both the header and y-pipe and relocate the turbocharger.
Luckily for us we had the turbo much higher than a front engine since we have more room. Even then our y-pipe didn't clear the trans shifter box. We had to cut and modify the existing stock rear manifold.

This project is definately not for the faint of heart. We'll keep you updated on the race results and progress. We have yet to do a full throttle 3rd gear shft. Lets hope it shifts as crisp as the 1-2 shift.