Discussion on LS4/4T80E non smog conversion
05-22-2011, 12:53 AM
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Discussion on LS4/4T80E non smog conversion For starters, I know I come up with some pretty odd ideas, but isn't that what hotrodding is all about.
I have a 64 Olds Starfire that get miserable gas mileage, about 12-13mpg on the freeway with a 700R4. Stock is 345HP and almost 400 ft/lbs torque. And that motor is a heavy *** beast. I looked up a Buick Rainier thats 4400 lbs (actually more than my car), with a 3.71 ratio, (though with a smaller N* motor 4.6?), and it's getting 19city, 24 hwy. I know my car is shaped like a brick so obviously thats a problem too, but beside that....To boot, that lower gear ratio would give me more off the line pending similar HP LS4.
My car has a perimeter frame which would allow a lot of room for a conversion like this. The idea is to mate a LS4 to a 4T80E and move everything to the back. Why? Because I can. Welding, fabricating, mounting not an issue. With aftermarket trans controllers, that will take care of the 4T80E. From what I gather I can get a stock ECM reprogrammed/retuned for a no smog application.
So, with that said, since size limitations won't be an issue, and I'll have a pretty generous budget, what would be your dream LS4 build? What would you think about a LS1/LS6 supercharger adapted or are the dimensions too far out?
I'm currently working as a field service rep in Afghanistan, and plan on building my own personal shop and doing a build of some sort when I'm done over here. So right now the only thing I can do is research online. Thankyou for your imagination in advance.
G.
I have a 64 Olds Starfire that get miserable gas mileage, about 12-13mpg on the freeway with a 700R4. Stock is 345HP and almost 400 ft/lbs torque. And that motor is a heavy *** beast. I looked up a Buick Rainier thats 4400 lbs (actually more than my car), with a 3.71 ratio, (though with a smaller N* motor 4.6?), and it's getting 19city, 24 hwy. I know my car is shaped like a brick so obviously thats a problem too, but beside that....To boot, that lower gear ratio would give me more off the line pending similar HP LS4.
My car has a perimeter frame which would allow a lot of room for a conversion like this. The idea is to mate a LS4 to a 4T80E and move everything to the back. Why? Because I can. Welding, fabricating, mounting not an issue. With aftermarket trans controllers, that will take care of the 4T80E. From what I gather I can get a stock ECM reprogrammed/retuned for a no smog application.
So, with that said, since size limitations won't be an issue, and I'll have a pretty generous budget, what would be your dream LS4 build? What would you think about a LS1/LS6 supercharger adapted or are the dimensions too far out?
I'm currently working as a field service rep in Afghanistan, and plan on building my own personal shop and doing a build of some sort when I'm done over here. So right now the only thing I can do is research online. Thankyou for your imagination in advance.
G.
05-22-2011, 03:24 AM
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Why would you wanna cut up a classic car like that and make it FWD? Why not just spend $3k for sub 1000 mile dropout truck 5.3/4L65E package? A RWD LS swap is pretty straightforward and can normally be done with existing parts.
That aside, there all sorts of technical hurdles to overcome if you were serious about thus swap: Aside from the obvious fabrication issues, what do you do for front suspension? Also, I'm fairly sure the Northstar bolt pattern on the trans is different than the 60 degree V6 pattern on the LS4, so you'd need an adapter plate, as well as customer converter solution.
I'm not aware of any 4T80 standalone controllers, but even if there is, you'd probably need a ton of custom programming on the stock PCM.
Not trying to throw water on your idea, but there are easier and cheaper ways to get LS power ib your vintage ride.
That aside, there all sorts of technical hurdles to overcome if you were serious about thus swap: Aside from the obvious fabrication issues, what do you do for front suspension? Also, I'm fairly sure the Northstar bolt pattern on the trans is different than the 60 degree V6 pattern on the LS4, so you'd need an adapter plate, as well as customer converter solution.
I'm not aware of any 4T80 standalone controllers, but even if there is, you'd probably need a ton of custom programming on the stock PCM.
Not trying to throw water on your idea, but there are easier and cheaper ways to get LS power ib your vintage ride.
Last edited by LS1 Racing; 05-22-2011 at 03:41 AM.
05-22-2011, 06:29 AM
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The idea is to mate a LS4 to a 4T80E and move everything to the back.
I have been rethinking the LS1 starter issue. The Northstar starter bolts are lengthways vs. crossways like the LS1 starter. This would allow me to bolt the N* starter to the adapter plate I would have to make anyhow. This would also allow me to use the N* flexplate. The starter would mount on the 'drivers' side of the block vs. LS1 stock 'passenger' location. Note:the N* is the primary engine to mate to the 4T80E. Also you can get one much cheaper than a built up 4T65E. It is about 80 lbs heavier dry.
Of course, now I'm getting into "why not just use a SBC"? Something I may consider. A nice SBC with aluminum heads.
As for the 4T65E vs. 4T80E, I'm not sure the 4T65E would handle the weight of the car vs. HP. Primarily the chain. As for a 4T80E controller, thats already found, several companies make controllers, FAST for example has one.
Again..why? because I can. It's not about cost.
Last edited by 73metalman; 05-22-2011 at 06:35 AM.
05-22-2011, 01:50 PM
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I guess I missed the part about it being in the back...My bad!
If that's the case, you can use the 4T65-HD that comes with the LS4. Even though they're notoriously weak in stock form, aftermarket shops like Triple Edge Performance can make these transmissions live next to high-powered motors in any application. This saves you from the complexity of physically and electronically adapting the 4T80E, and will also save some weight (the 4T80 is a big and sonnuva bitch!)
As for building an LS4, most off the shelf LS parts will work. Start with an LS6 intake swap and go from there. If you're looking to help mileage and are keeping DoD, there are plenty of cams out there that can help you make big power. If you're ditching it, you have even more options.
You can also do custom headers and then there's also a couple of ready made turbo kits, too. No superchargers available, however, since our motors are turned the wrong way, and we don't have room under the hood (of a stock W-body) anyway.
Anyway, keep us posted on what you decide to do...This will be fun!
If that's the case, you can use the 4T65-HD that comes with the LS4. Even though they're notoriously weak in stock form, aftermarket shops like Triple Edge Performance can make these transmissions live next to high-powered motors in any application. This saves you from the complexity of physically and electronically adapting the 4T80E, and will also save some weight (the 4T80 is a big and sonnuva bitch!)
As for building an LS4, most off the shelf LS parts will work. Start with an LS6 intake swap and go from there. If you're looking to help mileage and are keeping DoD, there are plenty of cams out there that can help you make big power. If you're ditching it, you have even more options.
You can also do custom headers and then there's also a couple of ready made turbo kits, too. No superchargers available, however, since our motors are turned the wrong way, and we don't have room under the hood (of a stock W-body) anyway.
Anyway, keep us posted on what you decide to do...This will be fun!
05-22-2011, 06:15 PM
#6
Applaud the creativity!
I am pretty sure there is no way for the 4T80 to nestle up along side the LS4. Here is a picture of it with a SBC:
but the SBC block is over 1" narrower and does not protrude more than 1/8" below the crank centerline, vs. the couple of inches the LS engines do. If the 4T80 would fit along side the LS4, it probably would have came with it.
The other issue is the starter. All transverse FWD GM transmissions are limited to use the 142 tooth ring gear. The OD of this ring gear is too small for sufficient clearance along side the block and oil pan. The LS4 GM Prototype oil pans were slightly different to accommodate the starter within the oil pan:
But probably due to heat or water/debris issues, its started ended up being transmission mounted:
The N* has the same limitations to a 142 tooth ring gear, and so GM placed the starter in the V between the heads (no pushrod camshaft to get in the way), so the 4T80 does not have any starter provision either.
I am nearing completion of installing a LS4/F40 6 speed manual transmission in the back of my 88 fiero, so I am quite familiar with many of the challenges/issues of using a transplanted LS4.
I am pretty sure there is no way for the 4T80 to nestle up along side the LS4. Here is a picture of it with a SBC:
but the SBC block is over 1" narrower and does not protrude more than 1/8" below the crank centerline, vs. the couple of inches the LS engines do. If the 4T80 would fit along side the LS4, it probably would have came with it.
The other issue is the starter. All transverse FWD GM transmissions are limited to use the 142 tooth ring gear. The OD of this ring gear is too small for sufficient clearance along side the block and oil pan. The LS4 GM Prototype oil pans were slightly different to accommodate the starter within the oil pan:
But probably due to heat or water/debris issues, its started ended up being transmission mounted:
The N* has the same limitations to a 142 tooth ring gear, and so GM placed the starter in the V between the heads (no pushrod camshaft to get in the way), so the 4T80 does not have any starter provision either.
I am nearing completion of installing a LS4/F40 6 speed manual transmission in the back of my 88 fiero, so I am quite familiar with many of the challenges/issues of using a transplanted LS4.
05-22-2011, 10:39 PM
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AAhhhhhh Thanks Thanks Fieroguru. I came across your other build with the 4.3. Seems you've really been going at this stuff.
Yeah my brain was really working when I was checking out some of the pictures for the starter...etc. Yeah likely buying a fully built 4t65 with the LS4 would save me headaches and likely money later on. I.e. having to build and adapter, etc etc. Since there would still be limits on the HP of the 5.3, maybe crank down the ratio with the chain drive, might lose a little on MPG but anything better than what I got would be very cool. Thanks again guru.
For me, thats probably one of the hardest things about being over here (afganistan). I don't have kids or wife, so having the money, but not being able to tinker really sucks!!!!
Yeah my brain was really working when I was checking out some of the pictures for the starter...etc. Yeah likely buying a fully built 4t65 with the LS4 would save me headaches and likely money later on. I.e. having to build and adapter, etc etc. Since there would still be limits on the HP of the 5.3, maybe crank down the ratio with the chain drive, might lose a little on MPG but anything better than what I got would be very cool. Thanks again guru.
For me, thats probably one of the hardest things about being over here (afganistan). I don't have kids or wife, so having the money, but not being able to tinker really sucks!!!!
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05-23-2011, 10:02 AM
#8
Here is a link to my LS4/F40 6 speed manual build thread. Lots of details about the ring gear/starter setup and solutions.
http://www.fiero.nl/forum/Forum3/HTML/000123.html
http://www.fiero.nl/forum/Forum3/HTML/000123.html
05-24-2011, 04:53 AM
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Back to the 4T80E I dunno, I'm still thinking a 4T80E, first because of the weight of the vehicle going in, but also the cost. I don't already have a 4T65e so I'd have to buy one or pay a core, which for the HD is $400-600. Then add in if I bought the rebuilt from Triple performance, and thats $1800, then add in upgrades, I'm closing in on $3000. A 4T80E can be had for under $500. I'm sure I could figure something out.
I'm still going with the LS1 idea with the starter removed. Bolting an adapter plate and use the N* starter and flexplate. I think I could fit a starter in the 4 o'clock position on the 80E bellhousing. I would have to cut out an LS1 flexplate center and weld it (or have it welded) to the center of the other flexplate. I can weld in general (subframe, frame, etc), but something precision like that I'd need done for me.
Can someone confirm for me that both the LS1 and Northstar are internally balance? i.e. no weights on the flexplate?
The toothcount between the two flexplate is 36 teeth with the N* being smaller(132) vs. LS1 (168). I assume the N* flexplate is smaller in dia. If I can make the LS1 flywheel work (LS1 has 3 converter bolts, N* has 4) by drilling 4 holes in it, then I would try that. My fear is the the dia. of the LS1 flywheel simply wouldn't fit in the bellhousing of the 4T80E.
Another issue I'm seeing is the shape of the drivers end where the half shaft exits. Seems there's a taper near the bellhousing, then bulges out at that exit.
I'm actually surprised how much difference there is in these GM similar products. Thankyou guys for entertaining my ideas for now since it may be a while before fruition. This job pays well, and considering the current economy....it's wise to ride this train to the end. And still reading your material Fieroguru...thanks again!
I'm still going with the LS1 idea with the starter removed. Bolting an adapter plate and use the N* starter and flexplate. I think I could fit a starter in the 4 o'clock position on the 80E bellhousing. I would have to cut out an LS1 flexplate center and weld it (or have it welded) to the center of the other flexplate. I can weld in general (subframe, frame, etc), but something precision like that I'd need done for me.
Can someone confirm for me that both the LS1 and Northstar are internally balance? i.e. no weights on the flexplate?
The toothcount between the two flexplate is 36 teeth with the N* being smaller(132) vs. LS1 (168). I assume the N* flexplate is smaller in dia. If I can make the LS1 flywheel work (LS1 has 3 converter bolts, N* has 4) by drilling 4 holes in it, then I would try that. My fear is the the dia. of the LS1 flywheel simply wouldn't fit in the bellhousing of the 4T80E.
Another issue I'm seeing is the shape of the drivers end where the half shaft exits. Seems there's a taper near the bellhousing, then bulges out at that exit.
I'm actually surprised how much difference there is in these GM similar products. Thankyou guys for entertaining my ideas for now since it may be a while before fruition. This job pays well, and considering the current economy....it's wise to ride this train to the end. And still reading your material Fieroguru...thanks again!
Last edited by 73metalman; 05-24-2011 at 05:06 AM.
05-26-2011, 01:28 PM
#10
I dunno, I'm still thinking a 4T80E, first because of the weight of the vehicle going in, but also the cost. I don't already have a 4T65e so I'd have to buy one or pay a core, which for the HD is $400-600. Then add in if I bought the rebuilt from Triple performance, and thats $1800, then add in upgrades, I'm closing in on $3000. A 4T80E can be had for under $500. I'm sure I could figure something out.
I'm still going with the LS1 idea with the starter removed. Bolting an adapter plate and use the N* starter and flexplate. I think I could fit a starter in the 4 o'clock position on the 80E bellhousing. I would have to cut out an LS1 flexplate center and weld it (or have it welded) to the center of the other flexplate. I can weld in general (subframe, frame, etc), but something precision like that I'd need done for me.
Can someone confirm for me that both the LS1 and Northstar are internally balance? i.e. no weights on the flexplate?
The toothcount between the two flexplate is 36 teeth with the N* being smaller(132) vs. LS1 (168). I assume the N* flexplate is smaller in dia. If I can make the LS1 flywheel work (LS1 has 3 converter bolts, N* has 4) by drilling 4 holes in it, then I would try that. My fear is the the dia. of the LS1 flywheel simply wouldn't fit in the bellhousing of the 4T80E.
Another issue I'm seeing is the shape of the drivers end where the half shaft exits. Seems there's a taper near the bellhousing, then bulges out at that exit.
I'm actually surprised how much difference there is in these GM similar products. Thankyou guys for entertaining my ideas for now since it may be a while before fruition. This job pays well, and considering the current economy....it's wise to ride this train to the end. And still reading your material Fieroguru...thanks again!
I'm still going with the LS1 idea with the starter removed. Bolting an adapter plate and use the N* starter and flexplate. I think I could fit a starter in the 4 o'clock position on the 80E bellhousing. I would have to cut out an LS1 flexplate center and weld it (or have it welded) to the center of the other flexplate. I can weld in general (subframe, frame, etc), but something precision like that I'd need done for me.
Can someone confirm for me that both the LS1 and Northstar are internally balance? i.e. no weights on the flexplate?
The toothcount between the two flexplate is 36 teeth with the N* being smaller(132) vs. LS1 (168). I assume the N* flexplate is smaller in dia. If I can make the LS1 flywheel work (LS1 has 3 converter bolts, N* has 4) by drilling 4 holes in it, then I would try that. My fear is the the dia. of the LS1 flywheel simply wouldn't fit in the bellhousing of the 4T80E.
Another issue I'm seeing is the shape of the drivers end where the half shaft exits. Seems there's a taper near the bellhousing, then bulges out at that exit.
I'm actually surprised how much difference there is in these GM similar products. Thankyou guys for entertaining my ideas for now since it may be a while before fruition. This job pays well, and considering the current economy....it's wise to ride this train to the end. And still reading your material Fieroguru...thanks again!
The N* uses a 142 tooth ring gear (11.91" OD) and the LS1 uses a 168 tooth one (14.096" OD). Here is a pic of a 168 tooth ring gear over the FWD Metric Pattern (and transmission bellhousing). The 168 tooth ring gear interfers with the bolt pattern and is still physically too large to fit with in the bellhousing.
Even the not so popular GM ring gear of 148 teeth will not fit within the FWD bellhousing.
06-18-2011, 04:24 PM
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I dunno, I'm still thinking a 4T80E, first because of the weight of the vehicle going in, but also the cost. I don't already have a 4T65e so I'd have to buy one or pay a core, which for the HD is $400-600. Then add in if I bought the rebuilt from Triple performance, and thats $1800, then add in upgrades, I'm closing in on $3000. A 4T80E can be had for under $500. I'm sure I could figure something out.
I'm actually surprised how much difference there is in these GM similar products. Thankyou guys for entertaining my ideas for now since it may be a while before fruition. This job pays well, and considering the current economy....it's wise to ride this train to the end. And still reading your material Fieroguru...thanks again!
I'm actually surprised how much difference there is in these GM similar products. Thankyou guys for entertaining my ideas for now since it may be a while before fruition. This job pays well, and considering the current economy....it's wise to ride this train to the end. And still reading your material Fieroguru...thanks again!
09-07-2011, 02:00 PM
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Whoa forgot about this thread So I read a little back on this thread and saw some of my retardation showing through. I'm not sure how I missed it early on, but the light bulb came on and made me realize that this setup would make my car a mid engine, not a rear engine. Thats even more work/fabrication that totally killed the idea.
Soooo, now that that's over, I bought a clean '65 Corvair and plan an LS1/996 swap on it. I will also look at an LS4/G50 swap, but holy crap those G50 trans' are expensive. I know the project will cost a lot of money, but I'm the kind of guy who likes to think of things that no one's thought of before that ends up saving a good chunk of dough. I still like the LS4 for the water pump output and overall shorter length. Hm...could you make a hybrid of the two?
BTW Guru, yeah, that truck is pretty cool. The reason I don't want the Northstar motor is the lack of support i.e. programming, headers, cams, etc. Also they're known for blowing headgaskets. Besides, it's even smaller than an LS4!
Soooo, now that that's over, I bought a clean '65 Corvair and plan an LS1/996 swap on it. I will also look at an LS4/G50 swap, but holy crap those G50 trans' are expensive. I know the project will cost a lot of money, but I'm the kind of guy who likes to think of things that no one's thought of before that ends up saving a good chunk of dough. I still like the LS4 for the water pump output and overall shorter length. Hm...could you make a hybrid of the two?
BTW Guru, yeah, that truck is pretty cool. The reason I don't want the Northstar motor is the lack of support i.e. programming, headers, cams, etc. Also they're known for blowing headgaskets. Besides, it's even smaller than an LS4!
