Twin turbo 16 valve Now Runing on MS2 and EDIS-8
 

We final got around and we finished up my MS2and EDIS-8 convention. Thanks to Tampa 928 and Shawn for helping . Car runs very well and now comes the tuning in about 3 weeks or so,, need to finish up so other things on the car. Need to get another fuel rail , Using 85/86 fuel rails with 42 pound injectors. So we think 500 RWHP or very close to that with the old Callaway turbos still on it.. Have not got around to getting the other turbos and manifolds yet . Pics to come . I need to finish up on Shawn's car first. I think i might have to jump up to 60 pound injectors with the other turbos installed later down the road.

Great job guys! You need to get some pics up Mark, so everyone can see. Are you around next weekend? I give you a call.

Yes ill be around,, We are going to be finish up on Shawns car next weekend.

Mark, who are you kidding. My car will NEVER be finished. Especially now that we have to tune your car. LOL

Tedward! Good to hear from you again. Where have you been hiding?

LOL Your car will be done before we start tuning on mine.

If I ever make captain I will have you guys turbo my '85 S2.

Keep up the good work!

N!

OK when ever you are ready

what would be a safe boost level/Horse Power output on a newly rebuilt but stock 4.7 16 valve "S"?

First : Is it a US or a Euro? And what year 4.7?

well I was just generalizing, planning ahead, I was thinking '83-'84 because I want to sell my '79 auto and get a 5 speed and these years seem to be the less pricey for the "s" 5 speeds. Twin turbo is one of the things I am considering, I was just hoping not to have to spend $25,000 on a long block decked out from 928 MS.

Corky Bell has a book that talks about turbocharging, and it tells you EXACTLY how much boost you can run with a certain compression ratio. As long as your compressed air-gasoline charge doesn't reach 1075 F...then you are good.

My 10.4:1 928S2 can stand about 5 psi of boost and stay under 1075 F with NO knock sensing ignition and live; That small amount of boost will produce a small amount of extra power, but since the 5 pounds of boost, even with a supercharger....is about $5000...It makes no sense to supercharge this car. 5 psi would not be noticeable in a car that already roasts its Falken RT-615 tires. These are 200 treadwear tires typically used on autocross cars. I put them on in order to tame my rear end, and it worked...for about 1000 miles. These are SOFT tires!

What this illustrates is that not every 928 should be supercharged, or even turbocharged.

My car? I would like to bore the block out to 100 mm, and then fabricate a turbo system using a pair of 951 turbos. 951 pistons. This would be as PORSCHE as possible....basically a twin-951. What would we call that? A 92851~

Tires: I guess I'd have to try Hoosiers.

N!

yeah I think I eventually want to run 15-20 lbs at least with twin turbo and water/ethanol injection, 80 or 100 lb injectors, and chilled intercooler ? (have to be able to beat those supras, evos, and stis) but i'm anticipating a few years into it before that.
Knocking can be prevented with the right amount of "octane"

I am more concerned about pistons and rods ending up in the next state.

You will not be able to run 80 to 100 pound injectors with the stock ecu,, But What HP are you wanting to get? With running 15 to 20 lbs of boost you can use 60 pound injectors and still have room for more fuel, But you will need to go a standalone ECU for fuel and ignition.

445RWHP is an awesome accomplishment the way I see it; exceptional job there.

I feel that there is so much potential in our 928 blocks with the case built so tough, epically looking at the 928 MS car.

but unfortunately I think I will have to spend $$,$$$ (which I don't currently have) on rebuild, parts, and computers before that happens. My friend has a custom supra turbo straight 6 with 405 hp to the rear wheels, its cool but it seems everybody I personally know who builds a car up like that has around 400. (don't worry a non German [or rather non 928] project car would never cross my mind) Being myself, my personal goal is to "come in at higher than average recreational performance automotive benchmark for my immediate geographical location"

I priced all the options from the 928 MS racer longblock and it came out to about $25,000. including bored and steel sleeved cylinders, super pistons, parabolic conn rods, the "800 HP without difficulty" crankshaft... (the works)

This is obviously blows my budget like a stick of dynamite. So until my graduating from the automotive program and getting a solid 40-60 hour job, a stock engine will have to do. Hence my original question: "what would be a safe boost level/Horse Power output on a newly rebuilt but stock 4.7 16 valve 'S'? " I was hoping around 400 hp for a turboed stock engine.
600 horse power + aka 4.? lb/hp in a slightly lightened 928 is my long term goal.

For now ill try to keep my dream bubble moderately regulated and go back to driving my '72 Bug. (until I sell it and my 928 to buy a 5 speed)

If you want big power, the cheapest route will be to spend circa $8k on a 5-speed S4, $3k in parts for intake manifold refresh, new shocks, timing belt job and engine mounts, and then another $5-7k on a supercharger kit.

Tim Murphy's Stage III kit puts down 550hp at the rear wheels and includes all the bits to fit including bigger injectors and custom ECU chips. And the S4 has knock sensing.

The stock S4 block is good for at least 16psi - Sonnett's brother just built a twin-turbo system for a guy on Rennlist who's so far got 660rwhp.. on a stock S4 engine, even running original head gaskets (no custom rods, pistons, sleeves etc).

I wouldn't bother spending $$$ on 928Motorsports stuff.

That was 689 RWHP on 17.5 psi on a stock S4 motor. I dont think the murf 928 ever made 550 RWHP on a stock S4 motor . At least I never saw a dyno sheet on it.. I agree with you on this I would buy a S4 5 speed and twin turbo that instead of a 16 Valve.

You're right on the Murf hp, its not up to 550.. coincidentally AO posted a thread today with a dyno sheet from Tim's wife's S4 auto fitted with a stage III.. 504 rwhp with torque converter losses.

John Kuhn's kit however is $11.5k, $3.5k more than Murf's to get to around 570rwhp at 12psi on a 5-speed (i.e. no torque converter losses - so slightly more hp than the Murf kit, but not a lot). Numbers on John Kuhn's own twin-turbo per this thread here and using updated figures from his sig.

The 670-ish rwhp car you mention, the only other Kuhn Twin-turbo'd 32V car, requires rather more spending, tuning, and electronics than the base Kuhn twin turbo, and is hardly a valid comparison (about as valid as using Todd's 675rwhp supercharged car as a comparison). If it was so easy to hit 670, surely John would have done it to his own car and used that as advertising? :)

Don't get me wrong - my personal preference would be for twin turbo if I were tempted by boost.. and I think John's kit is awesome - well engineered, and great production standards.

However for the average 928 owner wanting a bolt-on power mod, it's hard to compete with a kit that's got over 50 installs, includes everything to install it on the vehicle in a single package, plus is 30% cheaper.

It all depends on where you want your power,, you want it in your RPM ranger or do you want it at the top end. And remember you pay for what you get. If it was me and i was looking for a boosted system. I would go with the Twin turbo system and spend the ex money on the twin turbo system. I know Tim has sold a lot of systems but john is not out there to sell 100 plus system,s he is just sell a very high quality well engineered system. If I where to go with a S/C system i would go with DR system. John still at 12 psi he is still rich and he still has some more HP to get out off it. I have talked to him on this and he knows that there is more power to get out of it at 12 psi . We are thinking when he goes back on the rollers we are thinking very close to 600 RWHP

The car you are refering to is Tuomo's car. It does not require "rather more spending, tuning, and electronics than the base Kuhn twin turbo". Tuomo got ants in his pants and decided to pick the car up early, before the tuning was completed. I can hardly blame him for wanting to get his hands on that beast. He decided that he would buy a shark tuner and finish tuning himself because this type of thing is interesting to him. If you were to buy a Kuhn turbo system it would come with custom burned chips so tuning would not be something you would need to worry about. Other than that, the only thing you might want to upgrade is the fuel supply, depending upon your HP goals. The Bosch 044 pump is good to over 600 HP but Tuomo is going another route because he has plans to turn up the boost and lay down ALOT more power once he puts in the fresh engine. This is just stage one for Tuomo. :eek:

Anyway.. enough of the hijack.. I wanna hear more about the 16V twin project :)

Why not COP instead of EDIS? Ease of installation?

Which throttle sensor are you using?

MS-II seems like a great option for pre-LH cars.. I keep being tempted to pick up a CIS-based 928S (the 300hp "Euro" model) and have a play with MS-II or an alternative aftermarket ecu.. but I have to many 928's for now and need to make space by selling.