with the straight pipes i gain hp and the torque # stayed about the same i may have lost a couple but thats about it..............yeah i still think the exhaust is still restrictive because i got 2.5 downpipes and the exhaust has compression bends not mendrel (long story, don't ask)) however national speed does do fabricating so i think i'm going to ask them to make me a straight pipe exhaust system out of stainless with correct bends...........i think that once i get a quality exhaust system and 3" downpipes my torque will fall abit but hopefully i might squeeze some more horses out of her.................when i get home i'll find my dyno graphs and post them

-dave

 

Lookin good....

What year is your car? On my 04, with the stock cams still I am revin to 7200rpm in 4th gear. That helped alot, but the 3.3FD helped even more. No longer have to shift like a monkey on crack.....

See str8, stock cams are gonna RULE ALL!!!!

Tom

 

well according to my dyno graph i start loosing power after 6500 so i figured thats when i would shift do you think it would be more benfitcial to shift closer to 7000

 

Nah not much more beneficial in general. I would rev up there in 4th gear at the drag strip (on my few occaisions there) so that I could stay in 4th gear and not shift to 5th.

Yea the stock cams peak at around 6250rpm, after that they start to fall pretty drastically actually.....BUT you do retain that killer mid-range tq with stock cams.

Tom

 

true dat...........thanks tom

 

The proper shift point is at the point where your HP (on the downward side of the curve) equals the HP you'd be at in the next gear if you changed gears at that point. This is NEVER at peak hp - it is ALWAYS beyond peak - unless your HP is an absolutely flat plateau, which you already said it is not. It is also never the same for each gear (unless of course that RPM is your redline, which isn't optimal, but may be necessary to keep your motor intact, etc).

You are going slower by shifting at peak HP, guaranteed. The only way to calculate proper shift points is with a dyno graph and gear ratios. If you post up a dyno sheet I can calculate the exact optimal shift points based on that dyno for every gear. Depending upon the curve this could make your car drastically faster in the 1/4 mile (like on the order of a few tenths and a few MPH which is pretty huge), or have little effect. Just depends on your car's power curve.

 

Fixed. Wheel torque accounts for the gear ratios, which is what you meant.

 

Yes, I actually just thought about that and came back on here to edit my post, wheel torque (taking into account torque multiplication via gear ratios) is what you look at. Not WHP. Still of course requiring a dyno graph to determine the proper shift points.

 

I'd guess You prolly have a pretty solid trq curve, so in reality you might not even want to change than for a few more horses up top.

 

alrighty guys i couldn't find the dyno graphs that i wanted to post up, so i'll post up the ones i could find. Both of these graphs are before i started running the straight pipes. They're a little jacked up but again these are the only ones i could find, i'll try and swing by national speed and get another print out of my latest but anywho:



^the torque graph on this got screwed up



^this one has alot of runs on it. Its not the clearest one but i guess it will do. Like i said this is before the straight pipes and i couldn't find the graph with a single pull with torque not screwed up but tell me what you think guys.

-dave

 

Looks like a boost spike on ramp up. That's a nasty torque curve for traction.

 

i haven't had any kind of boost spiking issues.......... when you drop the hammer according to the gauge in the car the boost comes on smooth and holds steady at 10 and 17