[zakgreen69]

I have an 89 GT
According to the powerband on our cars - when is the best point to shift. How can I drive my car to make it as Fast in the 1/4 as possibel -
ps- mods include intake and shitty exhaust

 

[Rbodeman]

In my opinion the best point is just past 5000. Becasue the power band is very low in our cars for a 4 banger it is not necessary to go to the red line.

I know I will have a lot of people saying no no no. It is best to go right the the red line. However that is wrong unless you have completely changed the engine so much that the power band has move up. Shifting at red line (6250) will only bring the rpms down about 1250-1500. Still way past the peak torque and HP.

That is why the 5000 shift point is best. After each shift you will be at about 3500-4000. Right in the meat of the turbo engines power. Which is 190 torque at 3500 and 145 HP at 4300 (stock).

 

[Stage36]

this should be in the racing forum...

but while were on the subject, is it best to shift to where the torque will be higher in the next gear or power?

been curious about this one... i think its power but i read an article that said torque...

my dad just bought a saab 900SE... his peak torque of 191 lb/ft comes in at only 2100 RPM. dont tell me he should be shifting at 2.5K-2.75K...

 

[Guest]

Regardless of where the peak torque comes in at, a plateau follows or leads to it. That plateau is your powerband. That's where you want to keep your motor. Shift just when the plateau ends and that usually brings next gear right into the correct rpms.

It's torque that you should be concerned with when accelerating. Torque is the power that get's you moving. Horsepower is a mathematical equation based on torque and rpm's. Horsepower comes in handy when you want to maintain a high speed for a long time like Indy Car or NASCAR Racing. That's why those cars have motors that wind up to 10,000 rpms for horsepower but have relatively low torque numbers. Most of those Indy cars have awful 1/4 mile performance but can maintain 200+mph speeds.

 

[Guest]

I absolutely agree with Rbodeman!! All of his figures are right. I don't shift past 5200rpm at all. And I think the plateau that geok was talking about is around 3200rpm to 4600rpm, give or take a couple hundred RPM.

 

[Rbodeman]

Right Matt and right geok. Give it a try. You will notice how quick the car is and how fast it moves right along iF you shift just after 5000.

I have to admit its tough not to want to go further in the rpms when racing. Sometime i just go right up to the redline also.

 

[Guest]

The only true way to know when you shift is to have your car dynoed. Once you see where your horse power and torque start to fall, that will tell you when you shift. How depending on how fast and clean you do shift on average, then you could hold off until you know that when after you shift you will be in the largest increase of horse power and torque which will accel you faster. If you want to know more emial me.

 

[Stage36]

The only true way to know when you shift is to have your car dynoed.

or you can just try different shift points throughout the power band.

If you want to know more emial me.

or if you want a technical explanation, email Mike 94PGT. there was also a thread on this somewhere...

 

[Stage36]

Look what i found!

on second thought, dont bother him. i found the thread...

http://www.mx6.com/board/showthread.php3?threadid=1604

have fun...