[VegasGT]

Originally Posted by Pro Form Originally Posted by VegasGT Originally Posted by drgnracin72 anything past about 500 is unusable on the street even when using drs Your right, up to about 75 mph or so. Heck my buddies Z06 has 420rwhp and it has traction problems at 60mph or so. He runs a 12.1 @ 116 but he also weighs 31-3200 lbs. My mission is to pull on him, I figure 475rwhp or up will do it. We will see. I am at 469 rwhp and I can only get a chirp from 1-2...I hook all the way..mayby my clutch is slipping (helpng) but I like it....pulls hard...no traction issues here.

The streets in vegas are known to have less traction than other areas of the country. We have very little rain and alot of dust/dirt blowing around.

Also keep in mind your centrifical blower makes about 1.6psi per 1,000 rpm at 10psi. So your power and torque climb with rpm. A twin screw blower builds full boost by 2,000 rpm which makes for alot more torque at a lower speed. I took your dyno graph and a buddies graph with a KB and looked at the difference. I WILL DISCLOSE HERE HE HAD HEADERS AND A FULL EXHAUST SO PLEASE DON'T TAKE THESE NUMBERS TO HEART, but as a whole the graphs usually look similar to this between the two types of blowers. It looks like both ended up with about 11psi.

Now here is the difference, at 3,000 rpm your making about 185rwhp/310 rwtq, the KB at 3,000 rpm makes 280rwhp/490rwtq. At 4,000 rpm your making about 285/375 ft lbs and the KB at 4,000 rpm makes about 390/505 ft lbs. This happends till around 6,000+ rpm the Novi and the KB make the same power with the KB just about 35 rwtq higher. This is why a centrifical rolling on the gas will have more traction than a twin screw.

On the flip side of things, your able to make alot of power and keep the IAT (intake air temps) down because of the larger air to air intercooler. The KB and most twin screws have a small water to air cooler and at much more than 12-14psi get very hot and you can not run too long at WOT (wide open throttle). The KB can be pullied up to 24psi but I have a hard time believing the the belt will stay on and the IAT won't be HUGE.

[nbk13nw]

Originally Posted by T.M.-808- why did you lose 12 hp with 20's.From the extra weight? The stock tire is 26" tall,isn't your 20" tire also 26" tall?The dyno can't tell the diffence between 20 inch rims as long as the tire is still 26 inches tall..The track can though...he he..60 ft times...of coarse you kept the stock crappy 17's for track tires,yes? I can't wait to get my 20's....next month i hope..

Rotational weight. By adding more rotational / unsprung weight it requires some HP / TQ to turn them, so it is lost power to the wheels.

I run the Foose 20's. I lost 10 HP / 20 TQ on the same Dyno with the same mods, on a colder day as well. Each wheel / tire is 15lbs more than stock.

[itschristorres8]

i wonder how your car vs a new C^ Z06 whould stand
i heard from a dead stop they dont rip out of the whole to well

[Pro Form]

I wonder If I should go back with my stock wheels.

[Drgnracin72]

no keep em. they look badass on your car. keep the sotckers though and throw on some drag radials and have those be your track wheels

[ChrisJ]

^^^^What he said...

[flattusmaximus78]

General question here...how come max torque is allways lower. Is it cause most torque is used in the first few gears for a car to launch?

[Pro Form]

Offroad X pipe and plugs will be here monday....hope shes not to loud.

[itschristorres8]

Originally Posted by flattusmaximus78 General question here...how come max torque is allways lower. Is it cause most torque is used in the first few gears for a car to launch?

thats not true
i think the V6 mustang come with my torque then hp
plus ive seen plenty of mustangs with more tq then hp

[Pro Form]

My partners sl65 has 600 HP/700 TQ

[itschristorres8]

yea its just Pro Form's car thats all fucked up!
haha just kiddin
most cars do have my hp though..
but tq gives you numbers!

[Black Bullitt]

Nice numbers on the dyno. I can't wait to go forced induction.

[T.M.-808-]

Originally Posted by nbk13nw Originally Posted by T.M.-808- why did you lose 12 hp with 20's.From the extra weight? The stock tire is 26" tall,isn't your 20" tire also 26" tall?The dyno can't tell the diffence between 20 inch rims as long as the tire is still 26 inches tall..The track can though...he he..60 ft times...of coarse you kept the stock crappy 17's for track tires,yes? I can't wait to get my 20's....next month i hope.. Rotational weight. By adding more rotational / unsprung weight it requires some HP / TQ to turn them, so it is lost power to the wheels. I run the Foose 20's. I lost 10 HP / 20 TQ on the same Dyno with the same mods, on a colder day as well. Each wheel / tire is 15lbs more than stock.

I understand this...but how can the dyno operator say for sure "10 hp",thats a guestameet...
and everyone who mods there cars puts wider tires on there stock rims,or bigger rims,so why is it that folks seem to think that only the new body style losses power for bigger tires,and or rims?
Nice car by the way...

[T.M.-808-]

Originally Posted by itschristorres8 i wonder how your car vs a new C^ Z06 whould stand i heard from a dead stop they dont rip out of the whole to well

True,but they'll still run a mid 11 crossing the time line just after shifting into 4th gear out of 6.go to www.digitalcorvettes.com and watch all the street racing and track vids...killer vids...i used to be a moderator for years on that site..

[acehogg69]

What about changing the rear end gears to compensate for the 20's or even a 18's in the rear with a charger?

[T.M.-808-]

Originally Posted by acehogg69 What about changing the rear end gears to compensate for the 20's or even a 18's in the rear with a charger?

No gears needed to "compinsate",the 20 inch tire is only a 1/4 inch taller than the stock255/55/ 17" tire= 26"...285/35/20=26.1 inch tall.
It's the rolling weight that sucks a few ponys.Hope that makes some sense..

[GT/CS]

Originally Posted by T.M.-808- why did you lose 12 hp with 20's.From the extra weight? The stock tire is 26" tall,isn't your 20" tire also 26" tall?The dyno can't tell the diffence between 20 inch rims as long as the tire is still 26 inches tall..The track can though...he he..60 ft times...of coarse you kept the stock crappy 17's for track tires,yes? I can't wait to get my 20's....next month i hope..

Power can be lost due to increased wheel weight, true. However, even if you take a 25 pound 18in wheel and stretch it to a 25 pound 20 inch wheel you still lose power. It has to do with increasing the power needed to over come the inertia of the wheel to spin it.