help me drive!!!

Discussion in 'The Garage' started by 95PGTTech, Jun 1, 2007.

  1. 95PGTTech

    95PGTTech Well-Known Member

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    I thought I could drive after pulling consistent 1.9 60's in my 95 probe on "street" tires, and I can't figure out some things wrong with the cobra.

    I was told to shift around 5500, and it feels a lot sportier doing so than holding to redline. Is this true, and why does it feel dead above that rpm? It doesn't buck or stall and I've obsessive-compulsively cleaned out the MAF, the TB, the EGR, done the full tuneup, checked the canister, searched for everything - it doesn't feel like spark breakup or studdering, it just doesn't feel "fast."

    For example, running my friend's AEM intake Cobb catback 05 STi from a roll - 80mph 4th gear...oops...found out it's the wrong gear...put an instant car on him until he spools, where he flys by. Try it again in third, put a car and a half on him, he catches me starting fourth. This was shifting at redline.

    Shifting at 5500...When we go from a 5mph roll, he started 1 1/2 cars in front of me and we were dead even the entire time...we shut it down after shifting to fourth with me on his back fender, so I figure I pulled a little more than a car during that time. Had we gone to fourth he probably would have pulled hardcore on me again.

    Just general driving around showing off the new car, we were cut off really rudely by some old guy in a Lexus ES330. At the next light he turns left and we pull up into the lane next to him and I shift to second around 4000 to let him hear the exhaust and know I was pissed off. When I am about a car length from him he guns it so I chase and pass him pretty easily before shifting to fourth.

    Julia ran a 05-07 body style MGT convertible from 3rd doing about 85mph. He took a two car jump before she got on it and easily passed him before shifting to fourth, when she put another two cars on before shutting down. He flys by and gives the hazards...wtf...I was very surprised at this result, my only guess could be that it was automatic and his top was down. I drove a Miata once and with the top down it hits a wall at 100mph where it absolutely dies...

    When we went to the local hangout, she ran a EK hatch from a dig. He didn't want to say what he had, but from hearing later and seeing what we did it was a stick with a clutch, motor mounts, B18, gutted, some suspension, wide tires, and bolt ons. She knew she had him killed on power so she slipped the clutch from 2k, he took a two car jump, and quickshifted each gear around 5500 and passed him easily in third.

    All those races were quickshifting. Just for fun, we took the car out and both tried powershifting it (as during the first STi race, I had tried 3-4 thinking it was just as easy to do as in the Probe and missed badly, so never tried it again). Powershifting from first to second around 5500 breaks traction and it never gets it back. Ass end is about three or four feet squirrely in both directions. It is a very open area with room to spin out so I tried it two or three times and whether I feather it or stay layed into it, it never regains traction in 2nd. There is not enough room to be doing it for 3rd.

    They are Sammuto 315's inflated to 40psi on the rear.



    So...
    Is the car supposed to "choke out" like this up top or is there something wrong with our snake? Could it be the 2 1/4" catback restricting the car? I know the side exits give up a little power, but that's rediculous if it's just from those. I'm thinking of putting dual 3" electronic cutouts before the cats when we install the BBK LT's, because we both really like the side exit look and sound (I already have one of them).

    Am I shifting at the right point, and should I be powershifting?

    Why is it breaking traction like that? Crappy tire brand? Too much psi?

    Do the windows being up/down make that much of a difference, because although the cars sound cool racing the cobra seems balls-out faster with the windows up? A recent car magazine also was saying that it's better for your fuel economy to use the A/C than the windows due to the air resistance...
     
  2. uncltrvlnmatt

    uncltrvlnmatt Legend

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    You feel like you are dogging at 5,500rpm because that is probably where your peek rpm hp is.

    Your shift point is going to be trial and error. That is going to have to be something you figure out on your own. No 2 cars are exactly the same. It depends on engine and mods. But you want to shift at peek hp, that is not necesarily at red line.

    Your tires suck.

    With your windows down, the air comes in your car and gets trapped, so it acts kinda like a parachute. As far as better gas mileage with the A/C on compared to open windows. The A/C puts a huge hp drag on the engine, alot more than open windows would. I only use my A/C when the wife is in the car, because it sucks down the gas big time.
     
  3. GDawg

    GDawg Well-Known Member

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    I shift around 5600 to 5700 cause that's where my peak is. HP drops off quickly after that.

    My big problem is I need some wide drag radials cause I spin like hell even on these nice Eagle F1 GS-D3s. They are not a track tire. I have 2.7 60' time.
     
  4. trav_19

    trav_19 Legend

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    when im cruising around i use the air...its not like im drag racing around town lol and the hp you loose isint that noticable on the streets at least not to me...i thought on mythbusters they busted the whole a/c vs. windows down thing...they said you aucually get better mpg with a/c because of less drag
     
  5. GDawg

    GDawg Well-Known Member

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    When I lived in Vegas I drove with the top down and the A/C on... Took me three hours to get home... 11 miles. :comando:
     
  6. uncltrvlnmatt

    uncltrvlnmatt Legend

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    I must have missed that episode of Mythbusters.

    In my opinion, it depends on the car, engine, and driver.
     
  7. 95PGTTech

    95PGTTech Well-Known Member

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    Thanks for the replies guys. I am going to try and lower my rear pressures down around 20 and see what happens, as I need new tires for the front as well (275's rub on stock suspension at full turn, going to 245's). I'll probably end up going with some BFG DR's, I have had really good success with them in the past and I feel they won't grab hard enough that I will have to worry about our stock rear.

    Should I be powershifting? From trial and error, the 1-2 shift obviously is different powershifting versus quick shifting. 2-3 the car doesn't feel much faster powershifting than quick shifting, but I think I'm so concerned with trying to not miss the gear (so far, I've been able to do it one out of three times) that I wouldn't notice the difference. Whether 1-2 is faster or not powershifting is still up in the air because spinning the tires for 40 feet then having to let off is obviously not "faster" but tells me I'm delivering a lot more power to the wheels sooner.

    I think it's time for a short shifter, as the two of us are abusing the hell out of this transmission and evidently I suck at shifting. Unfortunately, I have a funny feeling I might remove the boot and find an aftermarket unit already, as my powershift into third keeps my hand about a full two inches away from my radio...
     
  8. 95PGTTech

    95PGTTech Well-Known Member

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    well, lowering the rear pressures helped dramatically, and I finally learned to launch it by slipping it from about 3000. one or less rotations of the tires and it goes. powershifting second...if the car is pointed perfectly straight, it chirps and goes. if the wheel is even the slightest bit off center, it gets squirrely and never gets traction back. it doesn't even feel any faster powershifting, so I'm done with that.

    any other helpful hints, other than get some suspension mods and some real tires?
     
  9. ripper

    ripper Well-Known Member

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    BFG d/r's 18lbs of air. Heat em up and watch how they stick. :eek:uttahere: Couple of times at the track and start lookin to do your differential clutches though :hammer:
     
  10. riored96gt

    riored96gt Active Member

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  11. scarface

    scarface Guest

    drag radials will be your best friend.
     
  12. 94Vert

    94Vert Active Member

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    stock preasure is like 32 psi i think so you shouldnt be over that. if you are going over 35 a/c is better than having windows down, but under that it's still not that big of a difference.