shaaark89

mark,
5 spots, wow! i'll have to watch that video again. quite a scramble at the start.
you were definitely in the right with galati if my humble opinion counts for anything.

Fastest928

HP does not break parts...torque does.

Skinny tires are a low cost "safety" valve for torque.

3/4th gears are the weakest due to the distance from the bearing carriers...least amount of gear support...etc.

Marc
500rwtq

mspiegle

This is some awesome positive response. Thanks to all you high-torquers for the responses.

Personally, i've broken a CV-joint before under a wheel-hop situation (hard launch), but that was BEFORE the supercharger. Since the SC, i've not had any issues.

slate blue

A question for Mark Anderson, the third gear you broke was that in a GT box or was that an earlier type box such as a G10,11,12,13? not the G55 that the GT uses.

Mark Anderson

"A question for Mark Anderson, the third gear you broke was that in a GT box or was that an earlier type box such as a G10,11,12,13?"

It was a while back but I believe it was a G28:10. The GTS box I have been using has never had a failure.

John..

I would consider my car a high torque application...probably about 450 ft-lbs through the stock tranny. I run Swepco.

Tony

Just and idea/thought/theory. Perhaps put a restrictor in the vac line on your by- pass valve. If my thinking is correct it should increase the amount of time it takes for the byapss valve to slam shut as well as the speed at which it closes. Both of which will ease the onset of full TQ at LOW Rpm.
IMHO, Im not worried about it...becasue at this point
Thats going to be my "fuse" in the whole thing.

Check this Cobra out. Sub 11sec on an Apten Eaton. Look at his boost gauge. No lag there!
http://www.carvidhost.com/vids/venomous.mpg
Pretty good shifttiing as well!

Old & New

Check out that car in the left lane on his last run.

JEC_31

Dang - that poor stock-appearing Cobrastang got smoked - by a chute-packing dragster. I wonder if there was a staggered start or if he really beat the racecar off the line and halfway down the track? 10:99 with barely maintaining control, that's some heavy duty street muscle.

Any of you SC 928 guys get that squirrely under boost?

Old & New

Uh, the only reason we don't pull 11 second quarters is we are running street tires and have 2.X rear ends...

Our supercharged cars are in the same class as that 'stang, except with with lots more class!

I'd run him through the *mile* any day.

mspiegle

@Tony,
Nice video, that car hauls some serious ***.

@JEC_31
Neither me nor Andy have much issue. The 928 seems to be pretty stable and predictable. Lots of wheelspin and forward movment. Not much else.



Is it the general opinion that the GTS tranny is better than the GT tranny, which is better than the S3/S4 tranny which is better than the old 16v?

GoRideSno

Mike,
Keep the drag radials on. I'll be back with the G-tech tonight. I' would like to get oyur 0-60 time. Can you send the link to log in to my supermodel e-mail to my hotmail address? ....never able to remember it.

Tony,
Interesting idea, I've thought of using a vacuum reservoir and a soleniod valve to controll the By-pass valve. Are you still in NM?

FWIW guys the BF Goodrich drag radials I've have are not big at all. They are 265s and are the same size as normal 265s. Very soft with a soft sidewall though.

This is a link to the drag radials at work. This is the 220k mi 87S4 witht he Autorotor. It is a 12.7xx sec run. BTW I drove this car from LA to Atlanta in about 36hrs. I had absolutely no problems with the car or the SC besides a loose hose clamp. I even crossed the Mojave, climbing from sea level to around 5000ft in 100+ heat. I averaged close to 80 on I40 (75 and 70 mph limit) and got 19 mpg with the AC on about half the time.

Andy K

Tony

Hey Andy, It was actually MN (Minnesota). We all got back Friday night. It was a much need break from the summer heat. My garage regularly sees 110'F in the afternoon. Time to buy a cheap swamp cooler i think. I hadnt seen my car or popped the hood in about a month...it gave me a fresh look and approach when i opened it on saturday. I cant wait to get it on the road again. My HE tank is done, idle stabilzer fittings are done. The welder messed up my aluminum expansion tank(put the fittings in the wrong spot) and all my gauges were sitting on the becnh when i got home...so i still have a bit to do. Ive got a new idea for an oil separator (where the filler neck used to be) courtesy of Louie and what he had at the IOC. Ill send a pic when i get back in 4 days(in LA now). I just have to adjust the shape a bit and get it made .

Yeah, as far as the vac restriictor, i dont see why it wouldnt work. It would take some trail and error to get it right i think. Like i said, im personally not going to mess with it as i think the bit of tire slippage present and the beefy S4 auto tranny should be able to handle it. Besides, my main goal and reason for the TwinsScrew is Low end grunt, a quick street car and gettign rid of that 2nd gear 30mph area of "foot to the floor and nothing"

John..

Hey Tony, you might want to check out the RMJ Aero Air-Oil separation system I have used on the Bastard and Goldmember. It is an off the shelf item and works quite well. A stainless steel pot scrubber can work well too, but you have to build it!

slate blue

Quote:

Is it the general opinion that the GTS tranny is better than the GT tranny, which is better than the S3/S4 tranny which is better than the old 16v?

Well from my homework I came up with this, the GT and GtS boxes are both very strong and have special gears. The GTS is the pick of the bunch because of it's oil cooler and cross drilled pinion. These changes could possibly be made to a GT box. A interesting point is the numbering of the gearboxes. Starting with the first borg warner style box that came in the 85 The G10 in then went G11 , G12 ,G13. Which was upto S4.There were minor changes made in each box.

The Gt jumps to G55 because of the major changes to essentially everything. It has specially ground ring and Pinion and the gears are made from a high grade crmo steel, then they are shotpeened with metal shot. Many other minor changes chucked in too. I would go looking for a GT or GTS box if you were going to punish it.