Supercharger vs gxp - Page 4

bradyb · 02-27-2009, 04:02 PM

A supercharger is always limited to engine RPMS. A supercharged engine will make X amount of PSI in relation to engine RPMS. If that same supercharged engine is at 5,000 ASL with 20% less air density it’s going to make 20% less power. That’s why if you come and run your car up here in Salt Lake you’ll run the ¼ mile a full second slower then you would at sea level.

The turbo is adaptive while making boost in relation to exhaust pressure/velocity. If you tell the turbo to make 21 PSI, that waste gate isn’t going to open up until it makes 21 PSI. It doesn’t matter if you’re at sea level or the top of a mountain in Colorado. The turbo is going to spool up a bit longer but you’re going to make just as much boost pressure.

Up here a supercharger is a waste compared to a turbo. A Stage 3 would be schooled by a GXP, possibly even a stock GXP.

Mac · 02-27-2009, 05:40 PM

As much as i like turbo i would think that if what you say is true brady we would be seeing at the 1/4 mile TOP fuel drags NHRA turbo's but i have never seen this and they are all Super charged at the top of the food chain. Unless something has changed in the past few years. ?

How about MPG? After installing the GMPP i get an easy 1.5-2.mpg better now. How does the stage 1-2 do in super charged MPG? JUst a veiwer here, since i bought the GXP i dont see an s/c in my future but for FI.?

jrsno1fan · 02-27-2009, 07:50 PM

As far as I could tell driving Randy's for the past week the SC actually got better mileage then my GXP. I get maybe 290 out of a tank, 300 if I baby it. Randy's got well over 300 out of a tank and I was hot-doggin it a little.

Mr. Stone · 02-28-2009, 08:18 AM

Quote:

Originally Posted by bradyb

The fastest Sols will always be turbo cars, that's just a fact of life.

Only in one respect.

Last I checked, to win you have to have some skill behind the wheel. There isn't always a need for a 300+ hp Solstice to be competitive.

bradyb · 02-28-2009, 08:21 AM

Quote:

Originally Posted by jrsno1fan

As far as I could tell driving Randy's for the past week the SC actually got better mileage then my GXP. I get maybe 290 out of a tank, 300 if I baby it. Randy's got well over 300 out of a tank and I was hot-doggin it a little.

Direct injection and a turbo is more efficient then a supercharger. That's why the stock GXP gets better mileage then the 2.4L even though it has 70 more horsepower. I average 35MPG with my GXP, what do the DDMS average?

Sure you might pick up a little bit better mileage with a tune for the supercharger but overall your adding more air which is going to require more fuel. The engine is also wasting 1-2 PSI just turning the supercharger.

Mr. Stone · 02-28-2009, 08:24 AM

So I've modded my car and all of the sudden I'm worried about MPG?

bradyb · 02-28-2009, 08:32 AM

Quote:

Originally Posted by Mac

As much as i like turbo i would think that if what you say is true brady we would be seeing at the 1/4 mile TOP fuel drags NHRA turbo's but i have never seen this and they are all Super charged at the top of the food chain. Unless something has changed in the past few years. ?

How about MPG? After installing the GMPP i get an easy 1.5-2.mpg better now. How does the stage 1-2 do in super charged MPG? JUst a veiwer here, since i bought the GXP i dont see an s/c in my future but for FI.?

The world's fastest door slammers are turbo cars, the world's fastest street legal drag car (7.8 sec 240MPH) is a split window corvette running giant twin turbos that also gets 18 MPG on the freeway.

Top Fuel dragsters are so far removed from anything that resembles a street engine they can't even be compared. They compress so much fuel and air together that a roots blower is just about the only way to compress 3,000 CFMS with a 1.7:1 fuel/air ratio to prevent hydro lock. From staging to the timing lights a top fuel dragster consumes about 30-40 gallons of fuel, not exactly a Prius.

Mac · 02-28-2009, 11:08 AM

My point was the TOP of the FOOD chain, they are pushing 330in the 1/4 and 0-100 in 1 sec. But MPG the turbo are very good at, with DI its even better.

The term Street legal? I dont think so. Pass smog in CAL? Also if any cop really looks at a modded car just about anything other than stock could set you up for a day in court, been ther done that. Depends on who and how he feels when he pulls you over. If the Cop is a tech you are in deep. Had to fight a court case once for my z28, lucky for me the cop that was against me was not a tech cop and case was closed, The judge did say if the CHP was a tech(not sure if they even have any? they must or this would have been a bad day for me ).

Critterman · 02-28-2009, 11:29 AM

Milage now we have gone full circle, but here you go:

completely stock -26 mpg best tank 30
Vector tune - 28 mpg best tank 32
stage I DDM - 28 best tank 31
Stage II DDM - 27 best tank 30

JRinKY · 02-28-2009, 04:49 PM

Quote:

bradyb : Direct injection and a turbo is more efficient then a supercharger. That's why the stock GXP gets better mileage then the 2.4L even though it has 70 more horsepower. I average 35MPG with my GXP, what do the DDMS average?

The turbo car also has a 3.73 drive axle vs the 2.4's 3.91.

It seems to me that if you average 35 MPG you are using very little of your available horsepower.

bun1t · 03-01-2009, 01:40 PM

One member here has ran a 12.9 with just a tune on a 2.0L. Whats the fastest time for a S/C 2.4L?

Mr. Stone, Perhaps a friendly competition between you and I would settle this. I've been ready for awhile now.

Critterman · 03-02-2009, 01:05 PM

I don't think a stage II has been to the track, I never got around to going. I wouldn't be a good example because I hadn't been to the track in over 30 years until I got this car and I only have 9 passes on it. Reaction time and 60' suffers

Randy@ddmworks · 03-02-2009, 01:54 PM

13.1 spinning due to lack of traction. then he was kicked off the track due to lack of roll bars in the open top.

duckSol · 03-02-2009, 04:00 PM

Was up in the high country and Asheville last week.
The difference is wicked with the DDM intake and tune

Still logged 31 mpg up there but don't call me Mitch

cooper1340s · 03-03-2009, 05:16 AM

I don't know how you guys get such good mileage. I get around 25 on the highway. Car runs like a bat out of hell (especially since Randy tuned it on Saturday in Orlando), but my mileage is nothing to brag about. Used to get around 30 when all I had was a ECM tune on a stock car when I bought it. Adding headers, high flow cat, cat back exhaust and noe DDM Stage II has improved my performance each time while lowering my gas mileage at the same time.