It doesnt really make a difference(Gen 4 or Paxton ) beg or expert( provided the beg has the ability to take the car thru the gears into the powerband )the trap speeds should be within a few mph of one another.My buddy (never been down a drag strip in his life )drove my Modded Gen 2 to within 2 mph of Smith )(same day same track )their ET were over a second apart BUT their traps were only 2 mph difference.
Took advantage of a track rental...analyze my run!
- Thread starter AbsolutHank
- Start date
Wheel diameter has zero to do with tire diameter. When you go upsize in wheels for any car, the tire diameter remains the same as OEM. Just the sidewall gets thinner. I've seen, on numerous message boards, similar comments as yours. I'd like to at least educate you on this subject. In fact, his 20" tire might even be a hair shorter than OEM, if he is running a Nitto INVO 345/20
Ryan, I wouldn't sweat the details. Your 60' and ET were damn good, especially for a first-timer. Trap speed will jump quite a bit once cold weather arrives. My Paxton coupe averaged 131-133 or so mph, with the highest pass going 135. It was a warm day, car put down 660 rwhp or so at the time. Keep in mind that the Viper is geared horribly for the 1/4-mile too.
Tony
Not educateing me at all bro..I am well aware that its the overall diameter..theats why i said MAY have reduced the gear...hard to say without measurments
Someone mentioned they were renting Atco.If so and they want to see what a Gen 4 can do in good weather let me know .A friend of mine (Kenny Miele lives near there )Kenny used to work for the mags as a test driver (holds 2 NHRA Records )and is damn near as good as Evan (excellent on stock tires ).In my Gen 2 he won the Mopar Nats one year .If hes available the track is prepped and the weather is good definately has the drivers ability to put a totally stock Gen 4 in the 10s (stock tires )
That would be great. I am usually the only Viper at these rentals.
Will send you the info.
Next Phase
Enthusiast
I assume this was the track rental at MIR last weekend? Did you notice a white Porsche Turbo making some quick passes?
Great results for your first time out, the mph does seem low based on what your hp numbers are. Your launches were great - especially with a 1.8 on street tires.
Great results for your first time out, the mph does seem low based on what your hp numbers are. Your launches were great - especially with a 1.8 on street tires.
AbsolutHank
Enthusiast
Yeah, the white Porsche owned by Jeff...that thing was running 10.8s I believe. He had some Busa's there too...nice guy
Next Phase
Enthusiast
Yeah, Jeff is good people... wish I could have made it out. That is a great track due to the elevation.
Nine Ball
Enthusiast
No, you said it WILL reduce it. Read it again. Even making an assumption like that based on larger diameter wheels shows that you indeed didn't know 20s use the same height tire. Don't worry, the majority of people think larger wheels = larger tires.
Well actually, 345 x 30 x 19" are taller than 335 x 30 x 18" by a little bit.
The height of the sidewall is generally shorter (would have been 25 or 20 to retain same height at a 19" rim) compared to a 30 series 18" tire.
I looked, but couldn't find the outside diameter. JonB knows
Ted
The height of the sidewall is generally shorter (would have been 25 or 20 to retain same height at a 19" rim) compared to a 30 series 18" tire.
I looked, but couldn't find the outside diameter. JonB knows
Ted
AbsolutHank
Enthusiast
To clear all confusion, I'm running 345/25R20 Nitto Invo's(26.79")
And Ted, the 19(27.14") you listed above is well over an inch taller than the 18(25.91") you listed.
And Ted, the 19(27.14") you listed above is well over an inch taller than the 18(25.91") you listed.
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Nine Ball
Enthusiast
Ted, here is how you decode those tire sizes.
Example: 345/30-19
345 = tire width, in milimeters
30 = aspect ratio for sidewall thickness, meaning 30% of the tire width
19 = wheel diameter, in inches
Tire diameter can be approximated by:
(sidewall thickness) = (345mm / 25.4) x (0.30)
2 x (sidewall thickness) + (wheel diameter) = (tire outer diameter)
Example: 345/30-19
345 = tire width, in milimeters
30 = aspect ratio for sidewall thickness, meaning 30% of the tire width
19 = wheel diameter, in inches
Tire diameter can be approximated by:
(sidewall thickness) = (345mm / 25.4) x (0.30)
2 x (sidewall thickness) + (wheel diameter) = (tire outer diameter)
Thanks. I never use the forumla because the tire companies forget to make their tires according to "proper proceedure"
Too often I would buy a replacment tire of a different brand and when I got the tires, they were 3/4" narrower than the ones on the car. Now I order tires according to their published measurements. Maybe some companies measure tread width and others measure actual width at sidewall?
My BFG Drag Radials 345 x 30 x 18 measure 13 in of tread while my BFG KDW2s 335 x 30 x 18 are 12 in. tread, my PS2 are just over 12 in tread. 335mm equals about 13.3 in or so. Cross section measure on all 3 tires is 14.3 inches or so. See what I mean ...
Ted
AbsolutHank
Enthusiast
Well my track event was rained out yesterday, so no new news. Supposed to find out Wednesday when it will be rescheduled.
Nine Ball
Enthusiast
You are exactly right Ted, those numbers are just general. Hence why I used the word "approximation" haha. There is no standards in the tire industry on sizing. Published manufacturer specs are the only real way to determine tire dimensions. The sidewall numbers just get you in the close ballpark.
Wish they would standardize. When I used to build chassis's it was very important to build the wheels tubs to EXACTING sizes. I always had to wait until the tires were delivered and mounted - or use tire sizes that I already had the dimensions of. PIA.
Ted
Don't be fooled that street tires can't pull great 60's, I've been in the 1.40's with a set of 345 Invo's on 20" rims. In regards to MPH, the driver doesn't really matter. Don't believe me? Go about 200', stop, take off and see how much difference in MPH you'll see from a full pass. As long as someone isn't letting out of the gas, you won't see much difference. Don't worry about what anyone else says. It's your car, enjoy it. You didn't build a race car, you have a fun street car.
The 13.49 rule has always sucked. Try running at an IHRA track vs NHRA, they might give you a little leeway, maybe. Otherwise you'll have to find a non sanctioned 1/4 mile track, which isn't easy. Needless to say when I take my convertible to the track in the late fall, I fully expect to be kicked out on the first pass. Going 5 seconds under the requirement tends to piss them off.
The 13.49 rule has always sucked. Try running at an IHRA track vs NHRA, they might give you a little leeway, maybe. Otherwise you'll have to find a non sanctioned 1/4 mile track, which isn't easy. Needless to say when I take my convertible to the track in the late fall, I fully expect to be kicked out on the first pass. Going 5 seconds under the requirement tends to piss them off.
The last day they ran my Gen 4 Gary Paterson of Shelby was there having Smith test a top line Mustang Supersnake.The car weighted 250 lbs more than My Gen 4 and trapped 135 mph .It dynoed at 675 to the tire.On Drs he was mid 10s on stock tires flat 11.0 .Point being if one has the weight of the car and its trap speed= fantastic barometer of horsepower
