blown 944

Mark, if your goal is a reliable 450 rwhp then I would absolutely go the LS route.

I have no problem with 450 hp with a 2.5 myself, but I also wrench whenever and where ever and don't mind it. If you want to stick with the 4 cyl then you would need a 3.0 IMO which means $$$$.

To those telling me about turbo this and that I think I've seen a few turbos

Back on topic. If you were looking for a reliable 350-400 hp DD, then I would just use the factory turbo parts and a gt30r .63 ar turbine. The spool would be quick and would be more than adequate for power. You would still need a standalone or a very nice chip with a an aftermarket knock retard setup.
You would be pressed to get 400 HP with pump gas w/o doing some headwork.

m73m95

You don't think you could get 450whp out of a turbo 2.5, and have it be a DD?

I don't mind the wrenching either but it needs to be reliable enough for DD duty.

I was thinking a 2.5 with coated pistons w/ oil squirters for cooling, deck plate, some head work, larger throttle body, and 20ish PSI boost. Obviously more to it than that, but thats a rough idea.

blown 944

Oh I know I can .. But not on pump, and not at 20psi. However most people may be frustrated.

450 Is a lot for a 2.5 and will not be as reliable at all, as an LS.

To get 450 you will need to be at over 24-25 psi and honestly most people would have trouble keeping the tune good to maintain those boost levels daily and it would have to be on race fuel or E85.
E85 is the easiest way IMO but still the engine has to be up to it and the tune needs to be monitored.

You may want to think about a 2.8 stroker as well.

m73m95

So, I've been running my CPU Dyno program (seems to be fairly accurate)

I built an NA engine on it. I just lowered the compression to 8.5:1 to do some tests.

with 20psi I get 385hp..... just playing around of course.

blown 944

What BSFC??

What VE??

AIT??

Crank or RWHP???

blown 944

F'n software
DBL

m73m95

settle settle LOL

I know you know your **** Sid lol...

V2Rocket

.50, 80. 40*F lol

V2Rocket

sid do you think 10psi would be too much on stock na engine with 91 octane and 50/50 meth mix (or higher meth concentration)?

m73m95

I think I pissed him off and he went home lol...

Spencer, why not run E85? Its easy to find in your neck of the woods...

Also, I run my program at 80% VE and 90* IAT, but what is BFSC? I know those programs aren't exact, but for playing around, its a lot cheaper to run it than swapping parts. Its fun too.

V2Rocket

there are only 4 E85 stations within 200 miles of either home or school for me.
the closest to home is 17 miles; the closest to school is 50.

BSFC is brake specific fuel consumption, basically how much fuel a certain engine uses per hour to make one horsepower. a general rule of thumb is that NA cars are about .50, turbo cars are around .55 and supercharged cars are .6 or higher sometimes

m73m95

Hmm.... I don't know if mine figures that. If it does, I haven't seen it.

On mine you can adjust fuel pressure, injector lbs, pulse....

here look.... http://www.auto-ware.com/software/eap/eap.htm Its an older program, but it serves it purpose.

blown 944

No, I was just messing around and then had to get out of the shop.
I was just curious what you were using for your figures.

The turbo comment was direct elsewhere .

Spencer the BSFC is a bit higher than .50 more like .65 on a turbo and when do you plan on driving your car to get 40f degree AIT?? he he.

Yea I think you could get away with 10 psi on pump with methanol just make sure the tank is full. I ran a hell of a lot more than that with E85 and methanol.

V2Rocket

i dont remember the thread name but a few weeks ago someone in the turbo/turboS forum did some calculation and the stock 951 engine BSFC turned out to be close to like .5 because the engine makes power pretty well for its size, probably has to do with the low boost pressure and relatively small turbo helping efficiency out.

as for my own car AWESOME! lol. would it make any real difference to run a higher meth concentration? i just chose 50/50 to try to keep it non-flammable, in addition to the water cleaning my engine and water being somewhat better at absorbing heat. with the meth at like ~120 octane does that basically raise the average fuel octane in the cylinder to counteract knock, without taking into account temperature drop?

also how much boost was mule running before you switched to corn juice?

m73m95

So....

Sid (Or anyone else), You don't believe I would be happy with a homemade Callaway turbo boosted to around 20psi? Even if I didn't hit my 450whp, you don't think it would be better than the extra $5k for the LSx swap?