Help with key parts for 800hp safe th400 build
07-12-2010, 01:14 AM
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Help with key parts for 800hp safe th400 build So my buddy is looking to build a th400 for his turbo'd cobra and he wants to build it for around 800hp range, i dont know anything about building a tranny and he just wanted me to ask if there is any special key parts he should make sure to have done in the tranny.
If anyone can post any articles, videos, parts lists, or anything that could point him in the right direction that'd be awesome!
Thanks in advance!
If anyone can post any articles, videos, parts lists, or anything that could point him in the right direction that'd be awesome!
Thanks in advance!
07-12-2010, 01:31 AM
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Transgo HD2 Shiftkit is about the best present you can give a transmission. Mind you with that much power if its not DD you might consider a racing full manual valve body. Then get the biggest trans cooler you can find, the TruCool 40,000 GVW is pretty popular, can disperse 45,000 BTU supposedly.
If you're going to do a full rebuild there's all kinds of internals that can be upgraded like clutches and whatnot, but the 400 is very strong to begin with.
The 4L80e (A th400 with overdrive and electronically controlled VB) can take up to 800 with just the shiftkit alone according to transgo (I think it was eight it may have been six I'll have to find the instruction). I don't know if that's true or not but my 80e has taken many years of hard abuse, from stopping my CCSB truck doing 40 (got thrown into reverse), to mobbing around in 4lo it's never given me any trouble.
If you're going to do a full rebuild there's all kinds of internals that can be upgraded like clutches and whatnot, but the 400 is very strong to begin with.
The 4L80e (A th400 with overdrive and electronically controlled VB) can take up to 800 with just the shiftkit alone according to transgo (I think it was eight it may have been six I'll have to find the instruction). I don't know if that's true or not but my 80e has taken many years of hard abuse, from stopping my CCSB truck doing 40 (got thrown into reverse), to mobbing around in 4lo it's never given me any trouble.
07-12-2010, 01:31 AM
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Transgo HD2 Shiftkit is about the best present you can give a transmission. Mind you with that much power if its not DD you might consider a racing full manual valve body. Then get the biggest trans cooler you can find, the TruCool 40,000 GVW is pretty popular, can disperse 45,000 BTU supposedly.
If you're going to do a full rebuild there's all kinds of internals that can be upgraded like clutches and whatnot, but the 400 is very strong to begin with.
The 4L80e (A th400 with overdrive and electronically controlled VB) can take up to 800 with just the shiftkit alone according to transgo (I think it was eight it may have been six I'll have to find the instruction). I don't know if that's true or not but my 80e has taken many years of hard abuse, from stopping my CCSB truck doing 40mph (got thrown into reverse), to mobbing around in 4lo it's never given me any trouble.
A temp gauge is also a good investment.
If you're going to do a full rebuild there's all kinds of internals that can be upgraded like clutches and whatnot, but the 400 is very strong to begin with.
The 4L80e (A th400 with overdrive and electronically controlled VB) can take up to 800 with just the shiftkit alone according to transgo (I think it was eight it may have been six I'll have to find the instruction). I don't know if that's true or not but my 80e has taken many years of hard abuse, from stopping my CCSB truck doing 40mph (got thrown into reverse), to mobbing around in 4lo it's never given me any trouble.
A temp gauge is also a good investment.
07-12-2010, 02:47 AM
#4
TH400 needs a few things at 800 HP but nothing extravagant.
It will need a 34 element sprag and drum assembly. I would run 6 directs and forward frictions, 4 intermediates. Hi Energy material. Proper steels to get clearance.
I would suggest a billet forward hub. If it's 800 NA or turbo, that's all you need. If it's N2O assisted to make 800, it may be wise to install an input shaft.
You can easily run it with an automatic VB, but you need to set it up for fixed line pressure and dual feed the direct clutches. You could also use a full manual VB.
I would rollerize a couple of locations. Heavy intermediate snap ring, if full manual add the brace to this.
Otherwise a solid rebuild.
It will need a 34 element sprag and drum assembly. I would run 6 directs and forward frictions, 4 intermediates. Hi Energy material. Proper steels to get clearance.
I would suggest a billet forward hub. If it's 800 NA or turbo, that's all you need. If it's N2O assisted to make 800, it may be wise to install an input shaft.
You can easily run it with an automatic VB, but you need to set it up for fixed line pressure and dual feed the direct clutches. You could also use a full manual VB.
I would rollerize a couple of locations. Heavy intermediate snap ring, if full manual add the brace to this.
Otherwise a solid rebuild.
