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The transmission I run is manualized, so I can hold any gear, I do not lock the converter though. The lock up clutch in the converter is only really good for cruising anyways.
edit:
It'll be close to your time you posted earlier, but let's verify, this will be one of the quickest in the forum
Do what? Do a test just in 3rd? Already did that. it was 1.67 on the dragy just holding 3rd start to finish. third gear is likely good for 125++mph with street tires and gearing. The slicks I run at the track are even slightly taller.
Below is first test starting in 2nd and shifting to 3rd gear. Likely didnt get full boost until about 60mph. No spool shot was used. Traction would be poor even with drag radials if starting much below 50mph and using the spool shot in 2nd gear with current road temperatures.
Actually looking at the rate of speed climbing and the gforce data it looks like it still lost some traction on the below test even without spool shot.
This test was just 3rd gear, but I did tickle the spool shot slightly a bit to help wake up turbo, but low tank pressure, so it was still likely around 60ish mph before full boost was reached.
With good traction and use of the spool shot I anticipate 1.2 to 1.3 seconds, maybe even better, for this data point when going all out. I will test for that next time at the track.
I'm dropping a 700whp+ capable setup in my E36 coupe in the next couple weeks and try to come close to those numbers. Gearing is longer, but that should help with traction, guess we will see
Probably underwhelming after Newaza’s post but I finally got a few pulls in this afternoon.
-271whp/239wtq running 91 octane
-6 speed/4.3 torsen rear end
-245 RT660s on 15x9s
-About 2600lbs with driver and toolkit/spares in trunk
-All pulls in 4th gear
I’m gonna say 2.8’s my average. I think I was on a downslope on the 2.6 run and the 3.0 run I was definitely on a bit of an upslope. Gotta switch to e85 and try again. Car’s JUST hitting full boost at 50mph in 4th.
Thanks man. It didn’t feel slow so I figured sub-3 must not be too bad haha.
Yeah, I’m in 4th more than any other gear on track. Occasionally 3rd and lots of 5th too. My gearing is too tight for my current power level IMO. I gave my buddy a ride along on one of our mountain roads yesterday. Dude drives a ~500whp Lancer EVO VIII and isn’t a stranger to quick cars. One of his initial reactions was “God damn dude, you shift a lot!”
I just got my hands on a 3.6 torsen so I’ll have to do another 50-75 test once it’s installed. I’m excited to run the 6sp/3.6 for the street, but also think it should be nice to eliminate a few shift points on track.
Lol. I'm using GPS Race Timer on iPhone. It's the first one that shows up in the app store if you type in "Race Timer". No useful telemetry or anything, but it gets the job done.
I feel like using a datalog would be more accurate than a phone (assuming no wheel spin). I honestly expected it to be lower than a 2.8 at your power levels, but what do I know. I wonder how much of that is due to the larger wheels, I know my car was a handful MPH slower in the 1/4 mile with my 245s.
I feel like using a datalog would be more accurate than a phone (assuming no wheel spin). I honestly expected it to be lower than a 2.8 at your power levels, but what do I know. I wonder how much of that is due to the larger wheels, I know my car was a handful MPH slower in the 1/4 mile with my 245s.
Have you actually had this on a dragstrip when you ran 1/4 mile? If so what was your 1/8th mile time and speed? Can you share the 60' time and the 330' time as well? Taking all that data into account gives a good indication of where the strengths and weaknesses are in terms of acceleration. You dont have to show if you dont want, I would just be curious to see that data too.
I've run just under 110mph in the 1/8th mile at the dragstrip when I'm on man boost. That correlates to somewhere in the mid to possibly even upper 130s in the 1/4 mile. The dragy and the timeslip from the track are almost always within a tenth and 1 mph. I've tested dragy, g-tech and performance expert at the track. The dragy is by far the most consistently accurate of the ones I've checked at the track when compared to the timeslips from the track, and you can be darn sure the track timers are ***** on accurate as they occasionally will host races that pay out some very substantial money. Also the dragy will not validate any runs going downhill more than 1% grade. Few means of time to speed measurement will be 100% accurate unless its directly measured. The dragstrip timers are king with lasers that are spaced at exactly point a and point b with the beams being physically broken by the front tires, and even they booger up occasionally.. It is rare, but I've seen it happen more than once.
The main issues I can think of with apps that use the internal phone gps is I believe most phones gps is 1 hz. So not fast enough rate to be super accurate if you are measuring a short time.
The issues with datalogs can be wheelspin as you say, but also road grade, potential rpm "jitter" in datalog, and tire circumference (unless that circumference is accurately measured of course, and tire circumference can vary with wear and tire pressure as well as rotational speed). That being said, if you can accurately measure circumference and do a run on the same road, in the same area in both directions to get an average then datalog would probably be at least as good as most other methods provided you are 100% sure no tire spin or clutch slipping and rpm data is smooth and accurate.
Have you actually had this on a dragstrip when you ran 1/4 mile? If so what was your 1/8th mile time and speed? Can you share the 60' time and the 330' time as well? Taking all that data into account gives a good indication of where the strengths and weaknesses are in terms of acceleration. You dont have to show if you dont want, I would just be curious to see that data too.
I've run just under 110mph in the 1/8th mile at the dragstrip when I'm on man boost. That correlates to somewhere in the mid to possibly even upper 130s in the 1/4 mile. The dragy and the timeslip from the track are almost always within a tenth and 1 mph. I've tested dragy, g-tech and performance expert at the track. The dragy is by far the most consistently accurate of the ones I've checked at the track when compared to the timeslips from the track, and you can be darn sure the track timers are ***** on accurate as they occasionally will host races that pay out some very substantial money. Also the dragy will not validate any runs going downhill more than 1% grade. Few means of time to speed measurement will be 100% accurate unless its directly measured. The dragstrip timers are king with lasers that are spaced at exactly point a and point b with the beams being physically broken by the front tires, and even they booger up occasionally.. It is rare, but I've seen it happen more than once.
The main issues I can think of with apps that use the internal phone gps is I believe most phones gps is 1 hz. So not fast enough rate to be super accurate if you are measuring a short time.
The issues with datalogs can be wheelspin as you say, but also road grade, potential rpm "jitter" in datalog, and tire circumference (unless that circumference is accurately measured of course, and tire circumference can vary with wear and tire pressure as well as rotational speed). That being said, if you can accurately measure circumference and do a run on the same road, in the same area in both directions to get an average then datalog would probably be at least as good as most other methods provided you are 100% sure no tire spin or clutch slipping and rpm data is smooth and accurate.
Very good information here, and I agree with pretty much all of your points. I did this on 195/50/15s that are relatively new so I just used the calculated size. If we're talking fractions of an inch of tire diameter vs 1hz on a phone's GPS, I'd rather go with a small inaccuracy in tire size calculations. Maybe add a tenth of a second for a more conservative guess. Also, the road's incline would cause issues with GPS or without unless it is dragy or another program that can show incline//elevation change. Using datalogs is probably going to be the best most people can do without owning a high refresh rate GPS device.
Regardless, to answer your question about drag racing: I've not been with this new turbo, only my old 2560R. It was a 13.3 @ 108mph around maybe 250whp. I will be going to the local drag races at Bristol Motor Speedway on March 23rd. Also worth noting the dragstrip here is slightly uphill. I might read a little online and see if I can find the incline.
On another note, I did a 5th and 6th gear pull and got the following results:
5th: Starting at 3190rpms/50mph and 157kPa, it took me 3.66 seconds to reach 4780rpms/75mph at 270kPa.
6th: Starting at 2685rpms/50mph and 130kPa, it took me 6.09 seconds to reach 4030rpms/75mph at 266kPa
Very good information here, and I agree with pretty much all of your points. I did this on 195/50/15s that are relatively new so I just used the calculated size. If we're talking fractions of an inch of tire diameter vs 1hz on a phone's GPS, I'd rather go with a small inaccuracy in tire size calculations. Maybe add a tenth of a second for a more conservative guess. Also, the road's incline would cause issues with GPS or without unless it is dragy or another program that can show incline//elevation change. Using datalogs is probably going to be the best most people can do without owning a high refresh rate GPS device.
Regardless, to answer your question about drag racing: I've not been with this new turbo, only my old 2560R. It was a 13.3 @ 108mph around maybe 250whp. I will be going to the local drag races at Bristol Motor Speedway on March 23rd. Also worth noting the dragstrip here is slightly uphill. I might read a little online and see if I can find the incline.
On another note, I did a 5th and 6th gear pull and got the following results:
5th: Starting at 3190rpms/50mph and 157kPa, it took me 3.66 seconds to reach 4780rpms/75mph at 270kPa.
6th: Starting at 2685rpms/50mph and 130kPa, it took me 6.09 seconds to reach 4030rpms/75mph at 266kPa
Cool. Thanks for extra info.
Yep 1hz refresh rate might be difficult to be accurate on shorter time measurements. Longer time measurements may help with the accuracy though. In regards to incline thats why it would be advantageous to make a pull in both directions and take the average. Unless one has something like a dragy or similar that measures incline as you said as well.
In your trip to dragstrip with old setup I would expect your 1/8th mile time and trap to have been somewhere in the mid 8 second range at roughly 85mph on that 13.3 @ 108 pass, Sound about right?
Post up your dragstrip data with new setup. It would be interesting to see the improvements with new setup vs old..
Better late than never. Got a couple pulls with the 5spd/3.6 setup on the way home today. Running a ~75% ethanol mix on wastegate pressure so maybe ~240whp.
Got a few 2.5’s in a row. 3rd gear. Real close to my 4th gear pull at 270whp with the 6sp/4.3. The car actually seemed to pull really well from 50-75. Maybe since it was closer to peak torque for longer than the 6sp/4.3 setup? I never recorded what rpm range 50-75 in 4th gear was on that setup but probably should have.
02-19-2024, 06:42 PM
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