Shane

Outstanding achievement!!

IcemanG17

DAMN..941whp at 20% loss is 1176HP.....by far the highest 928 ever..... 751ftlbs with over 600ftlbs from 4-8k is the MOST impressive......

Keep in mind this was on E85.....which allows for MUCH higher boost-power vs normal gas (even race gas)...... However I am sure Todd can put down 700+ whp on street gas with ease....

I do wonder what the lifespan of the driveline will be..... I would be STUNNED if it could survive one trackday or an evening at the drag strip..... Not many drivelines can handle 3x the torque for very long.....I also have concerns about overheating...... There are a few twin turbo Vettes that put down around 640whp I see at Thunderhill.....they typically run 1/2 a day and never over 80F ambient...even Evo's at maybe about 400whp (say 200hpL about like Todd) and they overheat all the time......

BC

Brian - as you suggest, e85 is a different fuel. Infact, the harder you push, the cooler the engine will get (to a point - you are still lighting a fuel off and creating heat). So at the track, he would probably get even cooler. No overheating for Todd.

GregBBRD

And now back to the regularly scheduled program....perhaps in a kinder, gentler, more honest way, that all of the members can enjoy equally?

Amazing results, Todd. I know that turbo engines are really easy on the connecting rods....but I had no clue that this was possible.

Be needing a stronger torque tube shaft? 300M. Pretty tough stuff.

You interested in testing one?

archer

me so horny

Lizard928

Hey Greg,

I may be interested in testing one of your 300M driveshafts in my turbocharged car.....

This work is very impressive results for sure.

GregBBRD

Cool. Let's talk!

I like to throughly test things long before they reach a retail customer....just how I do things. In my many years of business, I've noticed that others just like to sell...without any testing.....and then "update" as they go.....pretending like the original version never existed.

Just a different way to do things....who knows which is right?

I'm going to want to try and break them.....which might be easier than I think....which is why I need to test. The "original" material is a material that is designed to twist (without breaking) and then return to its original position.
300M is much stronger....but the shaft is very small, in diameter, and torque could fracture the material....if it can't flex.

The following is my theory....both from testing and observation.

The original material deteriorates as it ages....and twists farther.....which is why you will never see a low mileage torque tube shaft that has pulled out of the flex plate (and you don't need a supplementary clamp, for the first 50,000 miles or so), whereas a very used torque tube shaft can twist enough to pull out of the flexplate, in a manner of days (which is why these shafts need a supplementary clamp).

The downside of the clamps is that they don't prevent the worn shaft from twisting.....they just stop the shaft from pulling out of the flexplate. The result is that the "clamped flexplate" pulls very hard on the crankshaft and thus puts a large about of force on the front of the thrust bearing.

Lizard928

Greg,

is this for an autobox only?
My turbo car is a manual (what I'd really like it for), but we do have a local Stage III car that I am waiting to get that call from as he is an 89 (later shaft). So if I could get this and change before hand, it would be a wise idea.....

GregBBRD

No, have shafts for both manuals and automatics being made....as well as a 300M clutch shaft.....which do outright break and wear out.

Rick Carter

Great job Todd!

Ketchmi

Awesome job Todd! I'm willing to bet you could charge for rides in that thing. Maybe someday when I get the time or an interested customer I'd like to try the same thing myself.

Just for reference for the 944 folks that chimed in on this thread, this is our latest 3.1L 8v build, low boost was 16.5psi pump gas and high boost was on Q16 and 24.1psi. I would love to convert it to E85 but we ran out of cylinder head at this level. The turbo will push 30psi but with declining gains so we left it where it was still somewhat efficient. This is actually a very conservative tune.

IcemanG17

okay.....I don't want to be the negative nancy of this thread.....

but dyno's are one thing......and unfortunately when torque and hp both go up at steep angles it makes the car EXTREMELY hard to drive (think like Supras that make stupid power up high, but suck at EVERYTHING other than drag racing)......600ftlbs is NOT EASY to put down at all....nearly impossible in a street car on street tires....on race slicks (320's) you can do it IF the driveline can hold up.....which a street 928 setup CAN NOT DO....sure it can survive a 5 sec pull on the dyno or maybe 10 seconds on the street....but its just flat out too much for a stock driveline 928 to handle.....

Regardless of E85 or street gas....this type of power makes insane amounts of HEAT.....having turbos UNDER THE PEDALS......honestly I don't like that either, but for its designed purpose of a street-dyno car its okay....I have driven a Miata that had headers that got SO hot under the gas pedal it felt like my racing shoe was melting.....thats a car that makes 130whp.....

I'd say the texas mile type events are possible since they are over quick.....not enough time to melt the carpet to the gas pedal..... ORR event...NO WAY EVER....1st it would overheat and blow up or melt the drivers foot..... A track day is a no go as well.....WAY WAY TOO much power....it would break lots of driveline parts, before the engine even could overheat.....not to mention the brakes would be toast after a couple straights.....

okay stepping off my soapbox......I want a 928 that can do anything.....drive it hard all day....do ORR if I want...drag racing if I want.....whatever I want....sure I have a dedicated racer that is not street legal.....and I still break driveline parts with my brute 4.5L engine.....

BC

I don't see where you are speaking from experience on this.

This transmission has seen this and a bit less power for quite a while now. The transmission hasn't broken. The half shafts have not broken.

When you tune appropriately and spend the amount of time Todd and Luke have, things work better.

On the heat issue - Why are you again suggesting the car will overheat? I have already explained the dynamics of running such a "Cool" fuel. Not everything that makes alot of power creates heat it cannot move out.

Sometimes, things can just be designed... better - and normal run of the mill problems are lessened.

Its not a track car - nothing has been changed on the suspension.

john gill

Agree with the previous post , re the torque however , the torque can be controlled very well with the sm4 , as the with this monster amount of torque , you do not want it released on the driveline in the lower gears as you end up with multiples of this , of course with this calculation you can end up with 3 or 4 times this .
Modern ecus can be set up so the internal processor will know at what speed you are , and control the torque in this manner , also reduction between gear changes can be achieved also, it all get down to how much time the customer will listen to the advice from the tuner . And allow the programming time .
It is amazing that most will spend a lot of money of the engine build and then ,fail to understand that the calibrated final result also takes a considerable amount of time, with the tuning.
With a lot of power under your foot and the propensity to use it , it is inevitable that when you are beyond the original design specification of the components you have to expect that components will eventually fail spectacularly.

robot808

The way I understand it, Todd has been driving this car around for most of a year with 825rwhp without issue.
Why would you guys start worrying about his car now?