Silverbullet951

I was figuring out the power to weight ratios on all of the cars and i realized that with my car at 18 psi, I have the most power per ton. at 18 psi, I have 170.5 hp at the wheels per ton, the M3 stock, 167 at the wheels per ton, and the c4 stock, 120.6 at the wheels per ton. Now when this race goes on video, i think I could win. when you figure in the drag coefficients, I'm pretty sure the M3 has the most drag. What do you guys think?

Luke

what is up with you and all this "versus" crap...... drive your car the way you want to and smile at the other people on the road.

Silverbullet951

I drive it for fun every day, this is also just for fun. Lighten up man. I was just curious about the drag coefficients of the three cars.

Luke

didn't mean to come across harsh. I just dont understand car comparisons. everybody is talking about something different. It's a waste of time. It's like comparing running shoes before a cross country meet.

Silverbullet951

sorry to get out of hand too. I was just curious, I understand what you mean. Maybe it is a waste of time.

Silverbullet951

anyway, the frontal cx for the M3: .31
951: .31-.33
C4: .34

Robby

Technically speaking, and regardless of it's importance, the M3's Cx is .32 whereas the 951 comes in at .33- not sure about the C4, but I BELIEVE it is a .34 or .35- in any case, the Cx really isn't going to make too much difference in a race, even at high speeds- well, the higher the speed, the more the important it is- top speed is determined by both Cx AND frontal area- for instance, a 951 is .33 & 20.4 (square ft). A VR6 Corrado is .32 & 19.4 whereas 911's are usually around 19.1 and their Cx depends on the year, etc. I DO know that a C5 has a .29- WAY better than all these cars, as does a later CRX HF (the Si was a .30)- their frontal area has to be low too, obvioulsy- too bad they get squirrly at high speed (above 135mph or so)... Some other Cx's in case you're interested:
New M5: .31 (not sure why it's lower than M3)
Ferrari F40: .34
Late '80's Mustang GT: .38
Late '80's Mustang LX: .36
1st Gen Scirocco 16v: .38
1st Gen GTi 16v: .36
Late '80's Audi 80 OR 90 (can't remember): .29
Anyway...

Robby

Evidently we posted the last two responses at the same time- I see where you showed a .31 for the M3- these thing do vary from magazine to magazine for some reason. I got the E46 Cx's from Automobile magazine (don't normally buy it, but it had a test of ALL 5 of the E46 series cars- including the convertibles). The 951 has ALWAYS been a .33 as far as I've seen, and the 924 was always listed as a .32, whereas the 944 was a .35- AGAIN, from what I have seen- you may have seen different. I've seen the 968 listed from .33 to .34. BTW, the dif b/t the CRX HF & Si is supposedly the size of tires- the Si had 195's (I THINK) whereas the HF Gas mieser had smaller- I don't understand how this effects the Cx though- I would think it would affect the frontal arear, as Cx is supposed to be the SHAPE of the object whereas the area is the AREA...

pig4bill

M3 would be slightly worse than the standard 3 series because of the fender flares. Maybe the hood bulge too. There might also be different air management under and through the car considering the M3 would likely be driven at higher speeds.

benny dean

When it comes to comparing different makes and model of car I'm always interested. No two cars from different manufacturers can be the same thing to the same people, as such variety is the spice of life.

I love the 951, I'm quite convinced it's earned the tag "classic car" as well as my undying admiration. As a classic car, the 951 sets a benchmark by which other cars can and should be measured.

Rather than cry about about it, I would be more inclined to take pleasure from the fact that a 16 year old car still has such an incredible amount to offer.

Silverbullet951

benny dean, very true. It's very impressive that a 16 year old car is able to compete with these new cars and put most of them to shame. My cousin has to break in the M3 first, then we'll race. All I know is that I could be able to put up a good fight. I am surprised at the drag that the m3 has, It looks very bulky and big. To get off the subject for a sec, I heard that the hp increase per pound increase is 20 hp? if I raise the boost 1 psi, I add 20 hp? sounds good to me.

Luke

infinity G230 has a drag coeff. of .26 !!!!

Silverbullet951

does anyone know how much hp is increased when you increase 1 psi?

toddk911

Silver, I was told in here that each psi is about 10 hp. Theoreticaly, after 1 bar above atms. , it goes up exponetialy.

FYI, I read in Maximum Boost (The 951 Bible ) that once you have a good a/f ratio, every extra pound of boost requires 3 octane to keep knock at bay. I only mentioned this because I asked this before and was pleased to find the answer in the book.

Also Silver, unless the c4 is HEAVILY modded, and you said you are doing a rolling start, it won't even be close.

Silverbullet951

Todd, Sounds like the only competition i'll have is with the M3. The reason I asked about the hp increase per pound is because my cousin and I worked on and modified an rx7 third gen and we had dyno tested this car and we realized that when we increased the boost by one psi, there would be a 20 hp increase at the flywheel. The rx had around 300 at the wheels. we got rid of it and now he's getting the M3. My car runs really strong. I hope everything goes as planned. Later