94Cbra

A little "pft" isnt anything compared to the WOT whine of a KB though OB, damn it boy I thought you knew that stuff!

Birdieman4

...what a noob
Ok Obsol3te, here is more on my setup. I started with an S281E, so the blower was very capable of big boost, as was the engine with all forged internals. Stock compression was 8.5 to 1, so I was ok there. I had 42 lb injectors, and the mathmatical formula I came up with was that those 42lbers would support 600 rwhp as a limit. I had already put a digital wideband on the car, as well as MAF tuner. -So I had control of the engine parameters except timing. -So I had a cutom chip buned with a total timing of 17 degrees. This setting turned out to be about perfect, also keep in mind I am at 3000', so at sea level I'd probably be a little bit more conservative. The way the Saleen program works for the E is that when the heat exchanger gets fairly saturated and hot, it would pull a lot of timing, as a factory band aid to keep detination out of the picture. On the Saleen maifold, there are gaps where boost leaks occur; these were plugged. With the MAF tuner, I needed to richen up the fuel curve. I brought the car to an 11.8 to 1 a/f ratio. I prototyped 3 different pullies, in progressive sizes, to achieve around 17-18 psi. The stock pulley was 4'. I prototyped a 3 1/4', 3 1/8', and 3'. One plan was to use these pulley sizes as a final tuning measure, meaning if the tune was a little off with the 3 1/8', I could go up or down a 1/8' to compensate. Once I got the chip in it, all I really cared was the timing # was right, as the MAF tuner would clean up the fuel curve if the chip's program was off. The stock dyno on the car was almost exactly 400 rwhp @ around 11 psi. Keep in mind the stock vehicle was dyno'd in the heat, so it was pulling a lot of timing. At first, I was fighting belt slippage, so I sandblasted the prototyped pullies, which provided enough friction to help the slippage. At 17-18 psi, after the tune, I was making almost 550 rwhp. I was happy, as it was still streetable, but still a monster. One thing I had going for me was the stock 3.08 gears.(Saleen used this ratio on the first batch of E cars, trying to keep the gas guzzler tax down-it didn't work, as later E's had 3.55's) It turned out to be pretty ideal with the low end difference. By the way, the low end difference was about 3 universes apart from stock. It was tuned on 94 octane, and it was fine, no problems. If it ended up being too lean, I would have tried it with the biggest pulley, and then probably would have reprogrammed the chip with a degree less timing. The setup worked great until a couple weeks later when I brought the car in to the dealership for some minor warranty stuff, and a mechanic took it out on the freeway and crashed it. I talked to an eye witness, and what the mechanic did was downshift the car into 3rd, and he goosed it going about 65. The rear tires immediatly broke loose and he found himself spinning on the freeway doing 65. Both guard rails and a few spins later, the car was totalled. 05 E car, on the way, courtesy of the dealership. Obsol3te, if you have any detailed questions, feel free to ask. By the way, after this setup and tune, I raced a stock Z06 from a stop. By the time I was going 80, the Z06 was about 8 carlenghts back.

Obsol3te

Ouch... did you tell that story about the dealership crashing your car before?
Think I remember reading that...
Complete and utter BS
They better give you more than just an 05 E car...
All that time and money poored into that thing

And also, those 42lb injectors, they ran a-ok with the fuel as rich as it has to be when running a form of FI?
around 11-12ish.

I'm going to be making some pretty decent numbers later down the line, seeing as soon as I get my engine from the shop, I'll be adding that 150shot as soon as it's ready and willing.

And the winter of 05 is when I plan on getting the blower.
So, I'm not too sure the 42's may be enough?
And would they be OVERKILL if I had just got them with running the 331 normally on the street?
On the 331, prolly making around 330ish rwhp at 8.5:1 compression.
Then being upped around 450rwhpish... on the bottle, so the bottle should be fine but the casual driving on the street is what I'm worried about.

I do have a short list of mods that will transfer over, and I'm afraid I'm going to have to change my rear end gears too
4.10s seem a little too big for what I want to do now.

I'm almost definatly going with the blower, unless turbochargedpower.com can change my mind with their phonecall tomorrow.
But I doubt that's going to be the case.

Bah, and I still have to consider all the driveline/rear end work too...

Won't swarm you with questions just yet
This seems sufficient for now

Birdieman4

The insurance just settled today on the E car, and I came out well. I'm getting a check this week for $63,421. -Yeah, you'll need taller gears, but it will work to your advantage. Those 42lb-ers should be ok to at least 550 rwhp, at least. How are you gonna do the tune? Chip? I abandoned the chip for the MAF tuner. If I was doing it all over, I probably would have gotten a Steeda timing adjuster, as well. I say get the KB. I really think you'll be happier in the end, all things considered.

Obsol3te

Tune will be controlled by my SCT Flip Chip, that's already installed.
I can have it tuned for free up at the dyno I go to.
Thing works great, currently use it for when on and off the juice

2000GT4.6

[quote]ORIGINAL: Birdieman4

As I said, please tell me ONE instance of ANY twin screw/eaton type of supercharger being ran in a competitive dragracing class.

You can't, because there isnt any.

I guarentee you this: You set up a centrifugal/turbo car with the exact same setup as a twinscrew/eaton, and drag race em, and the twinscrew/eaton is NOT gonna cross the finish line first.

Great, so you make 550 FT/LBs at 1900 RPM, boosting the CRAP outta your engine every time you start it up and drive around normally, putting extra strain on it and making it hard to drive normally, and you still get your *** handed to you buy a car that is competely streetable and mild mannered (espically a turbo setup) until you take it past 3000 RPM.

You 5.0 guys are so centered on "Down low torque". How many times have you raced someone and shifted at 2500 RPM? How long do you stay down there in any race (christ, with a blown setup, what is it .2 seconds?)

Obsol3te

Ok, well you don't get make boost unless you're standing on the pedal, so driveability is nothing...
And you don't just make boost until like 3k in a twin screw, you make FULL boost as soon as you mash the pedal in any gear
It doesn't top off like in a roots
It continues to rise ever so slightly as you're driving it thru the rpm band.
Not as progressive as a Centrifugal or a Turbo, but it's still does.

So, what's so wrong about having full power down low and up high?
Instead of just up high?
And WHY ARE YOU DRIVING A v8! if all you want is up high...?

Birdieman4

...How 'bout top fuel and fuel funny cars?
If Obsol3te was building a race only car, I could see him running a different setup (TT's I bet). Backing up theories without experience doesn't help your credibility.

FoxGT

Ob, you have to make a choice, there is no in between for the setups do you want low to mid range power or do you want mid to high power? Also a KB will still give you psi in high rpm, just not near as much as turbos. How much psi you can get away with would mainly depend on your heads, intake manifold, & intercooler. One of my old friends was running 21 psi on 93 octane on an inline 6. & like Roundman said it is a VERY good idea to get an oil cooler

94Cbra, Top fuelers don't run turbos because it is impossible to run them the engine puts out too much heat for the turbo to handle. & you don't need the car running 3-5 minutes, 10seconds will work 30seconds is normal 60 is more than enough.

Roundman, the space & heat transfer you have will depend on how your headers are. You can make small turboheaders so less room will be used. & aluminum heat shields can be made to go by your exhaust to keep the heat to a minimum on other parts if you are worried about it alot. generally the moving air keeps the engine bay temp down

Lovemy88gt, most people don't have problems with the turbo spooling. They rev the engine till the turbo spools then let off the clutch & the tires spin, by time the tires grip they are already at full boost. Racing from a stop you usually dont have to worry about not having boost once you leave first gear.

Birdieman4, twin turbos offer better performance advanges on engines with two banks, ie v4, v6, v8, flat 4, ect... because you can design far better headers. Exhaust manifold design is a key to big power output. It is for this reason twins on a engine with two banks will spool faster, have less lag, & higher power output. The big problem with twin setups is synchronizing the wastegates.