FB Rx7 5.3 + Nv3500 Lechump car Idea
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FB Rx7 5.3 + Nv3500 Lechump car Idea
So I may end up with a very cheap 83-85 rx7 that is a 12a car. Of course the engine is toast and the car is heading to the crusher. So I am throwing out an idea for a lechump car build.
So the idea would be to take a 5.3 out of a truck and mate it to a gm nv3500 5spd. All this could be had at pick and pull for the lechump budget of a $500 car.
So the 5.3 part has been covered pretty well. Make some mounts and wire it up to the stock computer. Make what we have work on a budget. The big question is the transmission. Normally on a big build like this a t-56 would be a no brainier. However any lechump judge will say no go. So the idea is a 4.8 trucks engine 5spd which is the NV3500. Seems it would hold up to a stock 5.3. Make some shifter for it and a custom mount for it. Not the most common swap but hey would fly under the radar. Then just run a stock 5.3 for the race. Should be reliable enough.
So my questions are. How do the NV3500 hold up to a lot of shifting and maybe some hard shifts. Anybody know how the shifter hole compares to something like a t-56. Anybody think it would hold up or even work. I think it would be ok for some racing.
Got any ideas. I think it could be done under the $500 rules with some pick and pull prices.
So the idea would be to take a 5.3 out of a truck and mate it to a gm nv3500 5spd. All this could be had at pick and pull for the lechump budget of a $500 car.
So the 5.3 part has been covered pretty well. Make some mounts and wire it up to the stock computer. Make what we have work on a budget. The big question is the transmission. Normally on a big build like this a t-56 would be a no brainier. However any lechump judge will say no go. So the idea is a 4.8 trucks engine 5spd which is the NV3500. Seems it would hold up to a stock 5.3. Make some shifter for it and a custom mount for it. Not the most common swap but hey would fly under the radar. Then just run a stock 5.3 for the race. Should be reliable enough.
So my questions are. How do the NV3500 hold up to a lot of shifting and maybe some hard shifts. Anybody know how the shifter hole compares to something like a t-56. Anybody think it would hold up or even work. I think it would be ok for some racing.
Got any ideas. I think it could be done under the $500 rules with some pick and pull prices.
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I dont think a t-5 would hold up to a stock 5.3. I know people blowing them up behind a stock tpi 350. Gearing could be fixed later with a rear end change. Hello 8.8? Watched a few 0-100 in some trucks. 3rd is long. But this will be in a much lighter car. Are the NV3500 really that bad?
Last edited by 96Formula6spd; 10-22-2013 at 08:59 AM.
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I don't think they're bad, just not a suitable trans for the application.
If your just running a stock 5.3 I would give the t5 a shot, or see if you can find a World class T5, they were a little stronger apparently.
If your just running a stock 5.3 I would give the t5 a shot, or see if you can find a World class T5, they were a little stronger apparently.
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I personally am not a huge fan of the 3500 also. The t5 is so much easier to work on. I think they hold about the same amount of power. The input shaft bearing loves to take a dump on them and you need a special fixture to reassemble the case, pita.
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Any other options to go with. I know its going to be the fun of bolting it up to a ls1 motor. So a t-5 would need a bell housing to bolt up. Any other ideas. Being a lechump car I would need to last anywhere from 12-24 hours of constant driving. Ideas?
By the way here is the one blurry picture of the car I have right now.
By the way here is the one blurry picture of the car I have right now.
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I'd look at a 4.8 instead for the higher reving capability and throw a $90 OEM zr1 cam in it. Will make more power than the 5.3 rev much higher, and still be cheap. 4.8's are valued less than a 5.3 as well for an added chump car bonus.
Do the chump cars require a manual? I'd throw a stock powerglide in and call it a day...Glides are also bullet proof and dirty cheap in stock form. You'll **** off alot of racers with that combo!
Do the chump cars require a manual? I'd throw a stock powerglide in and call it a day...Glides are also bullet proof and dirty cheap in stock form. You'll **** off alot of racers with that combo!
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I'd look at a 4.8 instead for the higher reving capability and throw a $90 OEM zr1 cam in it. Will make more power than the 5.3 rev much higher, and still be cheap. 4.8's are valued less than a 5.3 as well for an added chump car bonus.
Do the chump cars require a manual? I'd throw a stock powerglide in and call it a day...Glides are also bullet proof and dirty cheap in stock form. You'll **** off alot of racers with that combo!
Do the chump cars require a manual? I'd throw a stock powerglide in and call it a day...Glides are also bullet proof and dirty cheap in stock form. You'll **** off alot of racers with that combo!
As for the transmissions I have not seen many automatics last long races. Yes a powerglide is simple and cheap. But would rather have a stick shift.
Would rather have a 5.3. Yeah gearing is not important. Need to be at the at hour 23 to go for the win in hour 24. Gearing might help. Stock rear end in a rx7 is either a 3.9 or a 4.1. So poor mans supercharger is already there. Bad gearing might help up the gas mileage some. Chump car rules make pit stops 5 mins no matter what. So less fuel stops are better.
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How much shifting is involved in a chump race? With a high-revving 4.8 and a light car I'd expect that most of the race could be run in 3rd. A T-5 might live if you aren't shifting it hard.
GM full size light duty NV3500 ratios from the wiki:
4.02
2.32
1.40
1.00
0.73
First gear would be entirely useless in a car that small with a 4 something rear end.
My 300ZX can hardly launch without cooking tires with a 5.3, 3.7 rear, and a 2.89 first.
GM full size light duty NV3500 ratios from the wiki:
4.02
2.32
1.40
1.00
0.73
First gear would be entirely useless in a car that small with a 4 something rear end.
My 300ZX can hardly launch without cooking tires with a 5.3, 3.7 rear, and a 2.89 first.
Last edited by i r teh noobz; 10-22-2013 at 07:09 PM.
#12
I had a FB w/ a "350hp/350tq" crate engine w/ a WC T-5 behind it and held up just fine straight out the junkyard, no rebuild.
I had a NV3500 to put in originally but if you look at the shifter location it would be in the dash of the Rx7, you'd have to build a linkage system just to use it.
And 1st gear was near useless w/ the T-5 as well.
I had a NV3500 to put in originally but if you look at the shifter location it would be in the dash of the Rx7, you'd have to build a linkage system just to use it.
And 1st gear was near useless w/ the T-5 as well.
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I think a t-5 might be the way to go. Making a linkage could be done. I have people who could fab that up. But I think a t-5 that took easy ***** along with its never going to be launched hard at a drag strip. A bell housing that is sfi could be covered as a safety item. Still looking at gas mileage. May dump the V8 plan for a miata motor. 1.5 hours of track time plus a refuel or go 4 banger and go 2-3 hours. Still looking into it. But with the shifter on the nv3500 being way back if we go v8 its a t-5.