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-   Tracking / Autocross / HPDE / Drifting (https://www.ft86club.com/forums/forumdisplay.php?f=39)
-   -   1/4 Mile times (https://www.ft86club.com/forums/showthread.php?t=7613)

Berserker 11-09-2020 07:14 PM

You are a more on paper type of guy and I am real world. Every proven all motor drag car is launching past peak torque by a good margin. I’m not saying you’re wrong but neither am I.

Until one goes out and tests hundreds of passes at multiple rpm launches does one know the best outcome. Put over 100 runs down this season just sayin

86TOYO2k17 11-09-2020 07:34 PM

Quote:

Originally Posted by Berserker (Post 3381860)
You are a more on paper type of guy and I am real world. Every proven all motor drag car is launching past peak torque by a good margin. I’m not saying you’re wrong but I sure as know I’m not.

Until one goes out and tests hundreds of passes at multiple rpm launches does one know the best outcome. Put over 100 runs down this season just sayin

From your posts it seems you have launched from 4k and below or 6k+ ?

I am saying launch at 4800 and see what happens. The only reason “paper” wont know the answer is because traction is a variable. Which i said assuming traction isn’t an issue launch at peak torque.

Dumping the clutch vs slipping it obviously also adds a human element and another variable that can change things. Finding the sweet spot of dumping vs slipping it to keep from bogging down, burning out, or wheel hopping while launching at peak torque. That’s the driver skill portion. The rest is mechanical physics.

DarkSunrise 11-09-2020 08:14 PM

Quote:

Originally Posted by 86TOYO2k17 (Post 3381829)
You should be launching at peak Torque roughly 4600-4800rpm. Lower RPM if you are getting too much wheel spin. At 7200 rpm you are at the lowest amount of torque same amount as the dip at 4k.

There's a lot more momentum built up in the flywheel at 7200 rpm vs. 4600 rpm.

icybrzzz 11-11-2020 08:16 AM

Quote:

Originally Posted by 86TOYO2k17 (Post 3381857)
4k-4500 rpm (lowest torque) is a big difference from 46-4800 rpm (peak torque) not sure why you referenced 4k rpm 3 times when I specifically said peak torque, not lowest torque, 4k would be the opposite of what I said.

Your RPM drops once your wheels hookup and rpm matches wheel speed. Such a high drop is because lack of torque at 7-7200rpm and 7-7200rpm translates to roughly 35mph wheel speed in 1st which you are obviously not doing even 1 second off the line. So once tires hookup engine has no power and rpm drop dramatically when launching at 7-7200rpm. 4600-4800rpm is peak torque that is what will get you moving off the the line the quickest. That is where you have the most power to keep from bogging down and keep RPM from dropping so much. Fastest way to launch assuming grip is not a limiting factor is to launch at peak torque.

Not really sure what the rest of your post has to do with anything. But short shifting at 7200rpm probably is not optimal. But i haven’t taken the time to calculate it. You can input your data into website i linked to verify.

I'm pretty sure @Berserker knows a thing or two about drag racing, I mean if you would do some research and realized his background in drag racing you wouldn't be questioning his methods LOL.

Good job on the 13.9! I'm going to need some pointers btw, I only managed a 15.2 that day I went to the strip on stock tires. I've only started to power shift recently and I managed to do a 15.0 on some 12 year old 205 16s lol

Berserker 11-11-2020 11:38 AM

Quote:

Originally Posted by icybrzzz (Post 3382275)
I'm pretty sure @Berserker knows a thing or two about drag racing, I mean if you would do some research and realized his background in drag racing you wouldn't be questioning his methods LOL.

Good job on the 13.9! I'm going to need some pointers btw, I only managed a 15.2 that day I went to the strip on stock tires. I've only started to power shift recently and I managed to do a 15.0 on some 12 year old 205 16s lol

Which track did you do that at? hit me up with questions anytime brother. If you already have a dedicated set of 16's for the track buy a NT555R :cheers: good fitment on a 6.5-7" wheel with good hook.

If you hit up the strip in the spring post up before you do man, would be cool to have a few 86's out at once :word:

icybrzzz 11-11-2020 11:45 AM

Quote:

Originally Posted by Berserker (Post 3382326)
Which track did you do that at? hit me up with questions anytime brother. If you already have a dedicated set of 16's for the track buy a NT555R :cheers: good fitment on a 6.5-7" wheel with good hook.

If you hit up the strip in the spring post up before you do man, would be cool to have a few 86's out at once :word:

This was at TMP, and yeah I've got some 16x6.5 legacy gt wheels I picked up for this exactly haha.

Sounds good ill def keep in touch for when the tracks re-open!

pope 11-11-2020 09:44 PM

Quote:

Originally Posted by icybrzzz (Post 3382275)
I'm pretty sure @Berserker knows a thing or two about drag racing, I mean if you would do some research and realized his background in drag racing you wouldn't be questioning his methods

I have a question.

@Berserker do you have a steel bell housing or explosion shield? The idea of dumping a clutch at 7k+ without one scares me, but I like having feet.

Berserker 02-12-2021 05:12 PM

Quote:

Originally Posted by pope (Post 3382514)
I have a question.

@Berserker do you have a steel bell housing or explosion shield? The idea of dumping a clutch at 7k+ without one scares me, but I like having feet.

Sorry for the late reply. Stock bell housing for me. It never hurts to have a sfi bellhousing but I’m my years of experience in mild combos like this I wouldn’t even think about it. On an extreme level my 05 Stang I put a steel sfi bell housing later in its life when I started going 10s. Even running deep into the 11s I was still rocking my stock alum bellhousing.

To grenade a clutch to the point of it coming off the flywheel is very extreme and hard to do in most cases. Driveshaft safety loop would be the first priority if you are on a full slick just for the piece of mind. If anything the shaft is coming through the tunnel before the clutch is. Again doesn’t hurt to have but personally I wouldn’t consider it until you start getting into big power or crazy 1.5-1.4 sixty foots and below.

ermax 02-13-2021 08:52 AM

1/4 Mile times
 
Quote:

Originally Posted by Berserker (Post 3347041)
Bringing this thread back from the dead :burnrubber:


Stock Brz with weight reduction

-Spare Tire / jack removed/ trunk panels
-Rear Seats removed
-Pass Seat removed (Driver seat Bride bucket)
-Ac Removed
-Stereo system Removed
-Curtain air bags removed
-Alum Drive shaft
-Whiteline Rear diff bushing inserts

Stock HP throughout:

-Stock Headers, cats, over pipe, front pipe & catback
-Stock pullies
-Stock Tune
-Stock air box with inlet tube
-Stock Fdr


With all that being said I ran a bunch of 14.6's @ 97-98mph. I didn't want to break out during 14.50 index eliminations, so if I went faster than a 14.50 I would loose.. As the day went on and the track surface got better, I actually ran a couple 14.6's letting off top end @ 93mph to win the rounds and not worry about going below 14.5's. I feel It would of gone 14.5's for sure of better near the end. Being on the stock tire I did full stand still burnouts at 22psi in the tires. I was launching the car at 4500-4800 which I found to be the sweet spot of carrying wheel speed above 5000 rpms but spinning through first and squawking 2nd. It was a pro .400 tree so I was more concerned trying to catch a light while keeping the 4500 hanging there as I bumped into the beams. I was almost dumping the clutch just to make it consistent each round. The 60 foots were terrible 2.3's but the wheel speed to the 330 was fair for what I was doing. Once I get it down into the 1.8's-2.0's the Et should drop a ton. I was power shifting every gear driving it pretty hard.

All in all it was a great first outing with the car & I plan to go to the next even in 3 weeks time. For the next round I will be swapping out to my light weight battery, disconnecting the front sway bar (Allowing a lot more weight travel) & probably bring my BBS wheels with the Drag radials to see how fast a Stock hp Brz can go with minimal parts. If I can crack a 14.3-14.4 on the stock tires and maybe a 13.99 with the drag radials.. I would be super happy :bonk:


Track was 35-40 C so super hot and about 34% humidity. If I remember correctly DA was 3200. More slips to come

http://i.imgur.com/WmcVGQp.jpg

http://i.imgur.com/UPrXcP0.jpg

http://i.imgur.com/M8gIMfZ.jpg


Man I’m kind of surprised it’s that slow after all that weight reduction. My old 1995 Integra GS-R ran consistent 14.2s and it was mostly stock. I had Type-R pistons, Type-R header and an OEM flywheel turned down to 13lbs. At the track I would pull all the obvious stuff out but also pull the rear seats and passenger seat. I would also remove the cat so it just dumped right after the headers. Haven’t taken my FRS to the track but I was figuring it would run 14.1 or better on E85. I guess I need to get to the track.

Edit: never mind I missed the part where you said it was bracket racing ant you were lifting at the end. Also the stock tires are a complete joke. Just about any 200tw tire would drop your time much less a drag radial. If anything the drag radial would give too much hookup on stock power.


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