Drag Racing W/ Forced Induction
 

We need a drag racing thread.

What setup are you guys running. Clutch, SC or TC, Tires, Suspension, misc?

I have p&l's kit and I launch at 4000 on 245/45/17 nitto nt555rs, @ 25 psi it wheel hops nasty, at 18 - 20 psi it wheel hops but not as bad.

What are you guys running, curious to hear other people's setups

Stock clutch, sprintex 210 SC non intercooled, hockey pucks, stock suspension, Tomei EL header, e85


12.9 @ 105.


3750 rpm clutch out slowly for best time.

To be completely honest, I feel we need an entire Drag Racing section. Somewhere where we can talk about different topics suspension adjustments, Tires, clutch tricks, launching aids, 1/4 mile times for N/A, 1/4 mile times for FI, drag car builds, ect..
Yes we all know these cars are great for turns and such, but the type of racing differs per person and preference. Sorry for the rant.

Edit: Thread created
http://www.ft86club.com/forums/showt...68#post2294768

Any idea how much WHP?

No idea, Estimating about 260-270

I did a few more test hits.... on a road in mexico...

I set my air pressure in back to 16 psi. Raised the 2 step to 6000 rpms to build about 4-5 lbs of boost to do a burnout. Lit them up for 6 seconds or so.

Lowered my 2 step to 5250 - 5300, preloaded the drivetrain with the hand brake, and slipped it out aggressively. I spun for about 20 feet and then it hooked and booked. No more wheel hop

The drag strip is going to react very differently than the street unless you are using dat juice they use on Street Outlaws. The strip is going to be prepped and give you a lot more grip so you are probably going to need more RPM to duplicate your results on the street doing the same launch.

Or go to poly bushings in the back, that's typically what causes wheel hop.


The bushings get loaded up then "pop" back into place and it's a never ending see-saw until the car finally hooks up.


Not to mention the continuous shock loads seen under wheel hop will break shit quickly.

I have poly diff bushings,
What else would you reccomend. Subframe bushings and what other suspension bushings?

Definitely do subframe or at least the Whiteline inserts, that's where most of the flex is.

Agree on the need for Drag Race section.

Interesting to see loading the drivetrain with a hand brake, good idea to reduce that initial shock. A hydro hand brake would would real nice for that.

Not as necessary if you slip out the clutch. I just do it for extra assurance. I know if you watch in car video of a manual awd car a lot them preload with the hand brake.

A perfect example is Devin in the red demon, see below.

[ame="https://www.youtube.com/watch?v=lwiE-YAx2S0"]Red Demon - In Car View - 8.0 @ 182MPH - Personal Best ET - Boostin Performance - YouTube[/ame]

Okay, So I did some passes at the strip last Saturday and i'm hitting the rev limiter before attempting to shift into 5th.

Current:
Manual Transmission
Unknown Horsepower. estimating 260-270 RWHP
Bridgestone Turanza El400 Hockey Pucks.


Relevant info:

Factory suspension settings
2013 FRS
Sprintex 210 Supercharger
Tomei Equal Length Headers
E85
70mm Pulley (~11 PSI)
Stock Gearing
215/45/17 tires resulting in a 24.6" tire diameter
7450 RPM rev limit
topping out at 12.9 at 105-106 MPH in 4th gear riding out the top 50 feet or so on the limiter



Due to the limiter I have a choice of attempting to shift to 5th or riding the limiter. 5th gear is impossible to shift into within 50 feet at 105 mph.


The easiest change is to increase the rev limiter to 7800:


Proposed changes option 1:
7800 RPM rev limit
top speed in 4th around 114 or 115


Since my tires are nearing the end of their useful life, I may be interested in changing rear wheels to 17x7.5 and tires to stickier street tires sized at 245/45/17 tires resulting in the following:



Proposed changes option 2:
7800 RPM Rev limiter
245/45/17 tires for a 25.7" tire diameter
top speed in 4th around 119 or 120


The last option is 17x8 wheels and tires with stickier street tires sized at 265/45/17 tires resulting in the following:



Proposed changes option 3:
7800 RPM Rev limiter
265/45/16 tires for a 25.4" tire diameter
top speed in 4th around 118 or 119, still simple




I probably put way too much thought in for a tenth or two, but every tenth counts in drag racing.


Anyway, Which setup makes the most sense realistically, not necessarily monetarily?

Option 4: Weir performance gear change to 4.56 or buy mine lol

I have a 245/45/17 on my stock wheels i still have to shift into 5th. Im not too good with with gearing but i think throwing a 3.73 is300 diff might help.
i hate it when you run out of gear and hit the rev limiter it just falls flat on its face instead bouncing off the rev limiter

What is your rev limiter set at?

What was the 60ft on this run? And how was the traction through 1st?

This particular 60 ft was 2.003 and the traction in first was nothing to write home about. The lowest I've gotten was a 1.9 60' on these tires.

8000

If you end up getting larger tires, it could help your 60ft alot.. The lower your 60 get the lower your trap speed gets. The lower the trap, maybe it'll help with not touching the limiter..

received my re-tune from @moto-mike today, Will be going to the track again soon, and posting some new numbers, hopefully.

Ditch the drag radials and get a set of drag slicks. When you launch, the sidewall wrinkles and that takes a lot of strain off the drivetrain and will help with that wheel hop.

Didn't realize that was you...NICE TIME!!! Making the most out of that blower for sure.

This!

Launching with boost on street tires (and drag radials are even worse) is a one way trip to something in the drivetrain breaking.

Get slicks, make sure the wheels are hub centric (or have hub centric rings), run them at 10-11psi hot. Smoke them in the water box, launch at 6500rpm. Profit.

If you're serious about getting the best time out of your setup, slicks are the only way to go. Anything else is just a waste of tire/clutch/drivetrain. I would bet money that slicks will completely eliminate your wheel hop unless you start making more than 400whp. Messing with bushings is just going to make your car more harsh and won't make you go any faster.

Background: I have over 250 passes at the track. In cars ranging from 150whp to 650whp.

I have launched at 7600 rpm and ran a 1.88 on drag radials. 86's are light hook up well with the right suspension mods and adjustments. I would not run less than 15psi in the rear any lower and you are just adding rolling resistance...

Road totally differnt from track tho shouldve tried this on the track

I have personally always used the ebrake to help preload.. I'd say it's definitely good practice

preloading is only really necessary on turbos or for hardcore racers, imo its just a good way to break shit for the average drag racer...

Preloading and leaving off the ebrake/slipping clutch is way easier on the drivetrain than just launching.

We couldn't make enough power off the line in my car with a 26" et street radial with dumping the twin disk, even at 6500rpm launch control. It would just bog and fall on its face. We made 4 passes changing things every time before a stock axle finally went out. We planned on going back the next week with a Perrin ebrake drift button and preloading/slipping the twin disk, which should have solved all the issues. But we have the trans out of the car for something much better at the moment so we won't be back at the track for a couple months I'm guessing. A lot of r&d to do first.

Best pass was a weak 11.7 with a 2.3 60ft from bogging. Mph was 130-133 all night

26" is big for that trap. I would think a 24.5 would be a better match, making 10's a possibility with the right setup / driver / track.

26" takes me to 8k rpm at the traps in 4th, saving me from another shift. wont be an issue when the auto trans goes in. im over the crappy shifting, twin disk driveablilty, failures, etc. ill be leaving off a trans brake now lol

Was at the track the other day. My best pass was a 12.2 @ 116 with a 2.0 60". If I can cut my 60' down I know this car has an 11 second pass in it as it sits. This run was lift shifting. I can cut a couple tenths by doing no lift to shift and launching a little lower and slipping the clutch more.
Not bad for my first ever time doing a pass at the track though.

[ame="https://www.youtube.com/watch?v=6ROKahJKEuk&"]Frs - YouTube[/ame]

http://i60.tinypic.com/eqqrlk.jpg

tires?

245/45/17 Nitto NT555rs on stock wheels at 18 psi

Ahh, that makes more sense. Good time. Would be even better with slicks ;)

Yea not trying to break shit haha. Ill just try slipping the clutch out more

Slicks are generally considered to be easier on your drivetrain than drag radials. They have "slip" built into the sidewalls. Reduces the shock load to everything else.

slicks do help drivetrain shock off the line because of sidewall flex. radials give less flex and create more shock, but you can run them spring/summer/fall here everyday. I have had zero problems even getting stuck in rain with et street radials. I prefer the "street car" setup

http://i22.photobucket.com/albums/b3...psw0ec775p.jpg

Also, In case you're wondering on the updated mod list-
Sprintex 210 Supercharger (Non-Intercooled) with Raceseng 70mm Drive pulley
Tomei Equal length header
Perrin 2.5" resonated cat back exhaust
100% E85 fuel
Stock Tires.

I'm going to be buying a clutch and a flywheel, as well as some slicks and wheels for the rear.