400rwhp And 410 Gears, Can Anyone Hook Up On Street Tires?

Discussion in '1996 - 2004 SN95 Mustang -General/Talk-' started by Brandonius 2v on roids, Nov 12, 2013.

  1. I have no idea lol. I have an upgraded valvetrain but still have the stock PI cams. I don't know what my RPM limit is.

    I have a 315/35 tire, have no idea what the diameter is.
  2. Assuming a 17 inch wheel size, 315/35-17s are 25.68 inches in diameter. 4.10s and a 1:1 3rd gear will get you 121 mph at 6500 rpm. I don't know this for sure, but I doubt you'll need to spin it any farther than that for optimal torque on the wheels with the stock PI cams. With my stock PI heads and mild blower cams, peak HP is at about 6100 RPM, and ideal shift point is around 6600. However, if your valvetrain is ok to go over 6500, you might could overspin it a bit only in 3rd just to get it through the traps. 7000 rpm would get you 130 mph. At your DA, I don't think you'll be going faster than that.

    Spinning the motor past the effective horsepower curve isn't ideal (a taller tire or less gear would be better), but you won't likely notice much of a decline. If you only do it in 3rd gear, and it's at the very far end of the track, ET will only suffer a very small amount, although trap speed may be down a noticeable bit.
  3. ^
    Extremely good info from somebody with a quick auto 2v. I'm not experienced with gearing/tire heights with autos, since the 7 sports cars I've had are 5-6 speed manuals. My whole focus has been on cutting a 60ft in street trim without dumping the clutch. My best so far is a 1.46 in full street trim. Never been a bias ply clutch dump guy since that's not the way I drive the cars daily.

    From the 60' to the 330-660' is really where drag racing occurs. Everything after that has much less effect on your 1/4 time. That's why you see bracket trailer drag cars run mid 9's to mid 10's at a much lower mph than street cars running the same ET. Also, use those online calculators for your tires and gearing.

    But when you want to make a big mph hit on the street with a lot of power, you'll be glad you have the gears to hook up.
  4. Nitto nt555r will do perfect for 400hp I also live in VA and own an 04 red fire cobra. I have stock IRS suspension with 315/35/17 and you will hook very good on the street. Also be aware that drag radials aren't gonna last very long max of 15-17k miles on nittos and 5-8k on micky thompson radials. your suspension is fine if you have the right tire you will hook all day!!! I've got a little over 500 rwhp and 575 ft lbs of torque and i barely spin on a set of nittos.
  5. Also if you go with mickey thompsons the 315/35/17 won't fit unless you have the 10.5 in wide rear rims but the nittos will fit on stock rims.
  6. @Nightfire , a taller tire is definitely not a bad idea. Personally, when you add meth, crank that D1 up and max it out.

    An IRS T56 Cobra is not a good comparison to your auto with 4.10's. Run the car at the track, log it, see where you're at. See how you like it on the street, tires, etc and go from there. I can guarantee you that your car will be virtually useless under 50mph on the street on those dusty, slick asphalt roads around El Paso. In Houston, we have gritty concrete freeways, so planting 1000-1500hp isn't an issue. Asphalt is like ice skating once outside the city. It sucks, and can be dangerous.
    85rkyboby likes this.
  7. Thanks for all the replies everyone, can I base the stickiness of tires on the treadwear number alone? For example I found some sumimotos(?) that are 200 for like 120$ each, I could afford to change them every year
  8. It's more complicated than that, but yes, lower treadwear usually means a softer (stickier) tire.
  9. In the 120$ price range, the sumitomo might be the best option for your tire size. But compared to a true drag radial, they suck. I pulled 1.6x 60' times using the nitto 555R with my 4 cylinder... and the nitto arguably has the least straight line traction of the drag radials.