how much HP can the NA trans really handle?
05-29-03, 10:22 PM
#2
Rotary Enthusiast
it really depends on how you treat it. You can probably get away with a modified TII engine on it as long as you don't drop the clutch or do any really hard shifts. It will probably eventually break though, so it's better to just sell it and put that money toward a TII tranny.
05-29-03, 10:28 PM
#3
Banned. I got OWNED!!!
Oh hell, bitchmill is wanting to rig up some ****... 
The tranny isnt so weak as everybody is lead to believe, but they can be broken. The clutch is the main weak spot...you need a strong *** pressureplate and a grippy disc to hold the torque of a turbo.
I once did the t2 conversion with only an engien and the stock NA drivetrain. Full boost in 4th at 120mph and the clutch just broke loose and started slipping. Yes, this was a like new stock NA clutch, so it wasnt just bad...it isnt large enough in diameter to hold that amount of power in stock form, without a PP that has a lot of clamping force. This is why on my conversion writeup I list a race clutch as the only way to use the NA drivetrain. Then, with said race clutch, you will tear out gears from the NA trans, unless you drive normally all the time, which for most people defeats the purpose of the swap in the first place.
The tranny isnt so weak as everybody is lead to believe, but they can be broken. The clutch is the main weak spot...you need a strong *** pressureplate and a grippy disc to hold the torque of a turbo.
I once did the t2 conversion with only an engien and the stock NA drivetrain. Full boost in 4th at 120mph and the clutch just broke loose and started slipping. Yes, this was a like new stock NA clutch, so it wasnt just bad...it isnt large enough in diameter to hold that amount of power in stock form, without a PP that has a lot of clamping force. This is why on my conversion writeup I list a race clutch as the only way to use the NA drivetrain. Then, with said race clutch, you will tear out gears from the NA trans, unless you drive normally all the time, which for most people defeats the purpose of the swap in the first place.
05-30-03, 02:20 AM
#6
White Comet
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I'll find out after monday. The t2 swap should be done by then. Im using a brand new RB HD clutch and PP with all new bearings, shims, seals etc. so I think it'll be a fair test. Mods on the car are as listed. Gotta give it a good break in period though.
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05-31-03, 02:33 AM
#8
it's not horsepower that kills the tranny it's torque.
well if a honda GS-R tranny can hold 450hp then NA tranny should do the same, mean no hard launches and quick shifting. Just baby it and it will last.
my friend has a stock drivetrain besides the clutch, and it holds up to his 10 sec runs.
well if a honda GS-R tranny can hold 450hp then NA tranny should do the same, mean no hard launches and quick shifting. Just baby it and it will last.
my friend has a stock drivetrain besides the clutch, and it holds up to his 10 sec runs.
05-31-03, 12:09 PM
#9
Originally posted by 600HP CLUB
it's not horsepower that kills the tranny it's torque.
well if a honda GS-R tranny can hold 450hp then NA tranny should do the same, mean no hard launches and quick shifting. Just baby it and it will last.
my friend has a stock drivetrain besides the clutch, and it holds up to his 10 sec runs.
it's not horsepower that kills the tranny it's torque.
well if a honda GS-R tranny can hold 450hp then NA tranny should do the same, mean no hard launches and quick shifting. Just baby it and it will last.
my friend has a stock drivetrain besides the clutch, and it holds up to his 10 sec runs.
do you think the NA FC trans could handle 250 torque with a couple good launches? with a heavier NA pressure plate and a little bit stiffer clutch?
Last edited by jacobcartmill; 05-31-03 at 12:12 PM.
12-22-03, 02:50 PM
#13
Seduced by the DARK SIDE
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Put some cheap 195/60's on it with >35PSI in them & you can burnout, smoke, & drift like crazy without breaking an input gear.
Ingredients to break an NA tranny.
Stock (heavy) flywheel.
Wide (grippy) tires.
Metal clutch (IE: copper or bronze)
Repeated nice hard launches (>4K)
Ingredients to break an NA tranny.
Stock (heavy) flywheel.
Wide (grippy) tires.
Metal clutch (IE: copper or bronze)
Repeated nice hard launches (>4K)
Last edited by SureShot; 12-22-03 at 02:57 PM.
12-22-03, 08:02 PM
#14
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I managed to break my S4 n/a gearbox fairly easily behind my turbocharged N/A motor...
Lost 1st.. then 4th.... then finally... 2nd...
I wasn't doing insanlely hard launches, did a few flat shifts though, thats undoubtably what killed it.
Good fun though..
Lost 1st.. then 4th.... then finally... 2nd...
I wasn't doing insanlely hard launches, did a few flat shifts though, thats undoubtably what killed it.
Good fun though..
12-22-03, 08:21 PM
#15
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I know it'll be ok upto 233 ft-lb with a light flywheel,
normal driving and launches under 4k rpm. I base this on how my 12a tranny has held up so I imagine the s5 one would do the same.
normal driving and launches under 4k rpm. I base this on how my 12a tranny has held up so I imagine the s5 one would do the same.
12-22-03, 10:28 PM
#17
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im running my NA tranny with my T2 motor, and havnt had any tranney problems yet except for the clutch. When i hit 10+ psi, it feels like the clutch slips occasionally (pausing, hesitating). I also think my throwout bearing is going as well, as i get some really weird chirping/clucking noises under heavy load at 6+ psi. Im not going to take the chance of blowing up my NA tranny though, and will be swaping in a t2 tranny soon so i can run slicks at the track this spring.
12-23-03, 09:49 AM
#20
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Originally posted by White_FC
I managed to break my S4 n/a gearbox fairly easily behind my turbocharged N/A motor...
Lost 1st.. then 4th.... then finally... 2nd...
I wasn't doing insanlely hard launches, did a few flat shifts though, thats undoubtably what killed it.
Good fun though..
I managed to break my S4 n/a gearbox fairly easily behind my turbocharged N/A motor...
Lost 1st.. then 4th.... then finally... 2nd...
I wasn't doing insanlely hard launches, did a few flat shifts though, thats undoubtably what killed it.
Good fun though..
As hard as you shift - maybe get a lenco.
12-23-03, 10:17 AM
#21
Engine, Not Motor
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Didn't realise the thread was so old...
FWIW, I have had no power related problems with my NA trans, even after some serious drag strip (> 10 PSI) abuse.
I did, however, kill two due to lack of oil, but that doesn't really count.
FWIW, I have had no power related problems with my NA trans, even after some serious drag strip (> 10 PSI) abuse.
I did, however, kill two due to lack of oil, but that doesn't really count.
12-23-03, 10:48 AM
#22
Former Moderator. RIP Icemark.
Originally posted by Aaron Cake
I did, however, kill two due to lack of oil, but that doesn't really count.
I did, however, kill two due to lack of oil, but that doesn't really count.
How many people have blown out a 15 year old tranny, that still had the same gear oil in it since 1999. Gear oil should be changed every year in hard applications, and racing applications every 6 months. Remember there is no filter to clean the crap out of gear oil. The acids caused by the oil/tranny being abused add a considerably higher factor to the longevity of the tranny than people think.
Also modern synthetic gear oils like neo, Royal Purple, or the redline MT-90 and shock proofs, considerably up the ability of the tranny to avoid distroying itself from too much power, torque and the acids caused by overheating the gear oil.
12-23-03, 04:53 PM
#24
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Mine just bit the dust after about 8 months, less than 10K km's on it.
Something totally broke up inside.. put it in first and let out the clutch and the car wouldn't move, just make a nice banging sound. 2,3,4 still worked, sometimes 1st was reverse! Cool! Then it locked up a block later.
Lots of teeth in the drained fluid!
Bottom line, NA tranny won't last long at 10 psi.
Something totally broke up inside.. put it in first and let out the clutch and the car wouldn't move, just make a nice banging sound. 2,3,4 still worked, sometimes 1st was reverse! Cool! Then it locked up a block later.
Lots of teeth in the drained fluid!
Bottom line, NA tranny won't last long at 10 psi.
12-23-03, 05:01 PM
#25
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Originally posted by SureShot
You broke 4th? That's hard to do..
As hard as you shift - maybe get a lenco.
You broke 4th? That's hard to do..
As hard as you shift - maybe get a lenco.
Maybe I _am_ just too abusive on my gearboxes, but hell my rx-7 is my fun car so it doesn't particulary matter if it's not working.
I had actually changed my gear oil just before I started loosing gears. My motor wasn't putting out that much power(torque..) either...
Admitidly my car did cop a fair bit of abuse though, taking out to the circuit every month.. but what really killed it was the flat *****(*) down at the drag strip.
*Flat ****, keeping accelerator to the floor and changing gears.