This may not belong in the FI forum, but lots and lots of people have been sending me PMs asking how a supercharger affects 0-60 times, so I'm posting here.

In the last couple of days the warming of the weather has coincided with my car only having 1/3 tank of gas so I have been able to get a few freeway 1/8th mile runs in. My 6MT G35 Sedan has the Vortech supercharger, Kinetix high flow cats, and the Stillen exhaust. To take the measurements, I'm using the most sophisticated consumer-grade accelerometer I know of (the GTech Competition Pro).

Best two runs (1/8 mile only):

60ft: 2.187s
330ft: 5.704s
1/8mi: 8.519s @ 89.29 mph
0-60mph: 4.981s

60ft: 2.149s
330ft: 5.740s
1/8mi: 8.625s @ 87.78 mph
0-60mph: 5.171s

To validate these numbers, I really need to go to the track, but for now I have just found a quiet area of flat freeway with a very large shoulder.

Getting a good launch is hard--normally I either bog down or squeal the tires all the way to the top of 1st gear and have to abort the run--but the warming up of the weather and the tires has helped. The probability of a reasonable launch is still only 1 in 3 or so and seems to work best when I rev to 1750rpms and simultaneously mash the gas and release the clutch.

I have two more mods (then I'm done--really--ok, almost done) which may positively affect 0-60 times and they are: JWT clutch/flywheel and lighter wheels with wider tires (my current tires are 235/45-18s). The third would be to raise the rev limiter since the 60mph mark and the 1/8th mile mark come right at the shifts into 3rd and 4th, respectively.

Incidentally, when my car goes in the shop on Thursday to have the JWT combo installed I am going to do similar runs on the loaner car for comparison purposes and to sanity check the numbers somewhat. I'll post those results as well.

--Steve

 

steve,

thanks for the research and posts. those numbers are right on line with what i thougt was possible after my ride/drive the other day.

i'll have to get another one after the JWT combo goes in...

keep up the good work.

sean

 

Sean, thanks for the feedback. I can't wait until Thursday to try out the JWT and I'll be sure to post my results with both the stock loaner vehicle and also the JWT. Purely in the interest of science, of course.

--Steve

 

I am excited to hear about your jwt clutch and flywheel.

 

very nice trap speeds but your times are only ok for them i think with some practice and better traction you could do even better for a comparison my buddy runs about those traps and gets consistent 8.0-8.1 in the 1/8 with slicks. keep up the good work

 

Absolutely... I'm hopeful that with some practice and some better rubber in back I can drop the 60ft time from 2.2 seconds to sub 2 seconds. A pair of slicks and--who knows--maybe 1.8 seconds. Under those scenarios, mid 12s is definitely possible for the 1/4 mile.

--Steve

 

dude if you can get it in the 8.0 1/8th range thats high 11s territory, good luck to be the first f/i in the 11s

 

and in case you guys haven't noticed, he is doing this in a G35 Sedan. it makes the numbers that much more impressive when you consider the gains over the stock performance of the car.

 

I honestly have never found or heard a Gtech or whatever they are to be very accurate, usually more giving then anything. Not to put your numbers down but it's just from experience. Like I've said in the past, I'd run ya from a roll or a stop, see if those #'s are valid being that I know my track times already

 

Bill, I'd love to go to the track with you guys as soon as it opens up on weeknights or Saturdays. Lemme know.

As for the possibility that the numbers may or may not be accurate--no argument from me. I've done a bunch of runs over the last two weeks but until I take it to the track I won't know for sure. I have heard that the GTech Competition Pro is quite accurate (and it ought to be based on how much it costs) compared to the old GTech Pro--but again I don't have any track runs to compare it to. If you throw out the trap speed numbers as being suspect, my times probably put me at no better than 13.0 for the 1/4 mile.

My goals are fairly modest... I'd like to break 13.0 at the track with wider street tires and at some point hit 12.5 with slicks. I don't think that's unrealistic, is it?

--Steve

 

Steve, I might be hitting up the track on a Saturday pretty soon, not Fayetteville, but another one that's out towards Highway 70 past Smithfield. It's a little longer of a drive then it is to Fayetteville, but it's open on Saturday, otherwise we can wait until Fayetteville opens on Saturday, which should be pretty soon. Trust me, you'll have no issues getting into 12's, as long as traction is there. Mid-low 12's shouldn't be an issue with slicks. You'll get there without a doubt.

Bill

 

Bill, sounds great. PM me when you have a date in mind.

--Steve

 

Guys

I took my car to the track and did some runs with the Gtech on. The times were within 0.1-0.2 seconds of one another. It is a fairly consistent tool. Note that I ma not saying accurate (as in ABSOLUTE NUMBERS accurat); it is VERY useful as a tool for determining deltas (differences) between mods on the same car.

Now, the 0.2 seconds error is right in line with Tesla's claims (the manufacturer). I talked to Peter, their tech guy, and he tld me that a new firmware is coming out within the next 2 weeks that will, for the first time, take advantage of the 3rd (vertical/z-axis) accelerometer to correct for upward pitch during acceleration (mainly) at the start of the run. According to their own testing, this increases the accuracy TREMENDOUSLY!!! - to within 0.02 seconds ! - a near 10-fold increase. If this new claim is even partly true - it is still a great improvement and would render the unit that much more useful.

Gurgen

 

Actually around here the GTECH is considered pretty accurate for the ET when compared to the track but traps about 2mph higher. I want the new one because I like gadgets but it's another 300 bucks I don't feel like spending.

As for the track, launching is the key. You can launch on the streets all day and hook but you will be real suprised your first day at the track when you bust out a 2.5 on your 60' with wheel hop and spin haha, it's all good we all went through it. Although there is the rare bread that goes to the track and busts a 12 on their first run. Doesn't happen often though. I used to go to the track and just "spectate", learn where the water box was where to stage etc. Keep us posted.