I know there's plenty of posts about what it can handle, and the limits of stock components etc. I'm WELL aware of all that stuff. (Aaroncake kinda proved most of that wrong with his ~400hp/~300 ftlb 6-port.)



I'm NOT asking for stock component limits, or why you think I shouldn't do it. I'm just asking what kind of numbers that you've put down with an NA drive train(Tranny, drive shaft, diff, half shafts)

If you can, please list the following;

1: hp numbers
2: tq numbers
3: tire size

Thanks! not hoping for a copious amount of feedback either, I'd appreciate anything at all

 

1. 146
2. 138
3. 205/60r15

 

Sounds pretty low for a TII motor / NA drivetrain

 

Pretty sure he listed the stock power, torque, and tire size for the NA.


Which is awesome.



I had my turbo engine behind a an drivetrain for almost a year. I don't do any drag racing or hard clutch drops from a stop.

After about 5 months I broke a input or output shaft on the transmission.

Rear end help up fine.

 

so you saw aarons post and made another asking what they can handle.. i'll bite

the last setup i built with those criteria i had the customer limit their goal to 250whp and it probably puts down about 270 when he drives catless(put down 246 with a HF cat). that was for reliability sake, not for him to figure out where he would need a new transmission, clutch, driveshaft, etc, etc, etc.

obviously the more power you make the more you will break, so what was the point again? what the n/a drivetrain can handle reliably? IMO stock n/a horsepower is about right, as i have already told him that the transmission will eventually break. after the dyno i thought it was done for because it was already making some strange noises...


can i emphasize enough that the non turbo transmission is junk? apparently not, because people still try to prove it wrong. i put a limit at 250whp/220tq, because that is about the most abuse they can handle without shitting on your chest even without doing drag launches or clutch kicks. it's enough to break traction through 2nd rolling on the throttle and any snapping to the drivetrain even once is enough.

 

I'll bite too.

Rebuild NA transmission with just 2k miles on it started making noise when I miss shifted to a lower gear. I didn't realize what I did until I stressed the driveline letting off the clutch. My trans now has intermediate shaft bearing noise.

It's a 6 port NA with ported exhaust.

 

we stripped the teeth off of 3rd gear with 160rwhp in the race car….


that being said it really depends on how you drive it, if you're gentle, and have a near stock T2 setup, i bet it would last quite a while, if you're an animal, 15 minutes, and then you'll break the T2 trans also

 

Im just using a na diff and axles. But I've put 3 hard years of drifting and haven't broke the diff or any axles yet.

240hp
220tq
205/55/16-245/45/17.

 

the diff and and axles can actually take a bit of abuse compared to the transmission, it is the weakest link.

 

I've had both in my garage. The na trans feels about 30lbs lighter than the t2 lol. Na trannys are garbage.

 

weight doesn't always necessarily mean inferiority, but in this case it holds true. the RX8 transmission weighs right between an n/a and TII transmission and strangely enough is about half way between n/a and TII durability.

but the difference is the RX8 transmission has 6 gears, so the drive gears are actually smaller than the n/a but it handles more power, through more durable materials.

 

My experience: https://www.rx7club.com/2nd-generati...plate-1000234/



Not sure of the horsepower since I never went to the dyno, but the setup was:

S4 hybrid with T04B v-trim wheel and housing @ 1 bar
S4 6 port N/A block
820cc primaries, 1000cc secondaries
Walbro 255
2.5 inch downpipe to 3 inch catback
FMIC
water injection
Transmission and rear end stock N/a stuff

Broke the clutch and couldn't shift, but the transmission held fine. I have broken tons of diff mounts and the mounting point on the rear-end itself. Haven't killed any transmissions yet. I have since gotten, solid engine mounts, transmission mounts, and rear diff mount. Also, now the engine is bridgeported with a BNR Stage 4 turbo, and full 3 inch exhaust. Not sure how much power it will put out but I may kill the transmission with this.

I guess you can call me hard headed

 

I tore the yoke off the driveshaft with stockish turbo power, i also tore the teeth off the spider gears on the na rear with stock na power.
I think it all depends on how you drive it.
I always break stuff on clutch drops.

 

I beat the crap out of an NA transmission for 2 (3?) years at the 400HP level. Then I obliterated the input shaft and cluster shaft gear on a 3rd gear pull one day. Swapped in another NA transmission. That winter I also upgraded the open diff to an LSD. The following summer it didn't take much before the 2nd NA transmission was about to fail, and it did, blowing away the input/cluster shaft. It didn't help that I started tuning higher boost at around the 500HP level. It took exactly 2 pulls at 16 PSI before it started making noise.

Upgraded to a TII transmission fully built by a local transmission shop. Drove that for 2 years and then ended up snapping the driver side stub shaft on the NA diff. Swapped in a TII diff and axles. Now, nothing is going to break catastrphophically but the TII transmission is starting to whine.

TII stuff isn't indestructible or magic...At the 500HP level, the lifespan of the TII transmission isn't guaranteed.

So what am I trying to say? NA stuff can work great if you aren't getting much traction. An open diff is a fuse in a way. One wheel will be spinning and at the higher gears you don't get the shock loads. But you get the right conditions or enough power, the tires dig in, and frankly the NA stuff just isn't strong enough. Typical failure would be input shaft gear if you are in 1st, 2nd, or 3rd. In forth, you'd snap the input shaft.

Same with the diff. Everything is fine until you get traction then it's mainly a matter of luck and how you drive.

On stock turbo numbers, it can be reliable for years. Again, depending on how you drive. But if you are building some real power, consider any NA drivetrain parts as temporary use.

 

Aaron, whats you take on the intermediate shaft bearing failures?

From what I have heard and experienced myself, this is one of the most common failure points on the NA trans. I accidently shock loaded my drive train (see post above) and mine whines just 2000 miles after a rebuild. Cris Ott told me that it is such a common problem, he has hardly driven an NA that didn't have that bearing whine.

(my shifter bushings got overlooked during the rebuild and the resulting shifter slop caused my mis-shift).

 

a whining TII transmission doesn't mean what it would on an n/a transmission though, but the paranoia after breaking the 2 non turbo transmissions likely engrained it there.

my original TII transmission has been whining since i bought the car 10 years and 80k miles ago, it does get louder ever so slightly over time but the bearings can really only wear so much until the whine presents itself and then rather suddenly it just stays like that.

you could keep replacing the input bearings, but i have never felt the necessity. of course the lighter oil i put in it enhanced the whine but that was the sacrifice for smoother shifting.

the only TII transmissions you ever really hear about failing are from drag cars, pushing at minimum 500whp. and of course the weak 5th gear syncro which cracks from mis-shifts to 3rd into 5th.

 

I ran around 500 passes on my old na setup back in the late 90's-00 era, but it didn't have much power (9.7@74 in the 1/8th) never had a issue ...ran 225/50/17 BFg drags

 

appreciate all the input. Again I wasn't asking what the limits were, just wondering what people were putting down through their NA parts. Thanks!

 

I'm sitting around 300 horse I believe. NA base model. The car was originally 4 lug. swapped in turbo brakes/hubs, original trans/open diff. Over 50 drag strip passes all over 4k rpm. 6500 rpm clutch dumps on slicks for at least 20 passes with 1.7 60'. no transmission noises. I did kill the spider gears in the open diff however. I ran a 12.0 @ 116 on a BNR stage 3. Need to hit up the dyno and get a "proper" tune, my timing is rather conservative.

 

Super weird how peoples experiences can vary so much.

One guy pushing stock hp blowing every driveline piece, another guy pushing 300hp launching at 4.5k..

Pretty mysterious right?? Precisely why I made this thread!

 

they have always been quite hit and miss, most people break them when not even trying to.

 

Some people just bang on it to hard while others know how to keep **** toghter ...its the same with every car....

Are you gonna be drag racing?

 

the only proper way to bang on that transmission is with a sledge hammer. those who have been lucky with them should just accept what it was, luck.

the same is said about the RX8 series 1, it's both made of glass and that it is more durable than people give it credit for. both of course are true but if it doesn't happen to like what you're doing it will just do what it wants, like snap an output shaft..



that was at stock 13B-MSP power level of roughly 185whp, and i consider that a stronger tranny than the older n/a 5 speed.

 

Only reason I chose to keep the N/A drive train is because the car will see road course more than drag strip now that I have the tune dialed in. Plus, N/A parts are a lot cheaper to come by. I picked up my N/A LSD for $75. After hearing how weak the transmissions are here, I assumed when it died at the track I blew the trans. If it wasnt that I assumed it was the driveshaft. Never expected it to be a spider gear..

 

Looks like I won't get to chime in on how the new setup worked on the N/A driveline...