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Drag race tips (questions)

Posted: Thu May 17, 2018 12:57 pm
by HoldenPPV
I am an old guy and have not drag raced anything modern. Really have not raced since the 1970’s and then mostly on pumped up 900/1000cc Kawasakis. Sometimes a manual transmission car (1969 Dodge Dart with a 340 Six Pack I built and put in there).

My question is this. Leave traction control on? Or push button in to turn traction control to “performance mode”? Or hold traction control button in for the 5 seconds to turn traction control completely off? Which of the three is best for a good launch?

This car is a 2012 9C1 with the only mods being a Solo Performance axle back exhaust and a Green Performance drop in air filter. No tune.

It’s important to an old guy who has been challenged by his youngest boy who has a quick little BMW that I probably won’t beat, but it’d be great if the 4,200lb Aussie’Merica sedan put in a good showing.

Re: Drag race tips (questions)

Posted: Thu May 17, 2018 5:33 pm
by Pursuit
Just in stock tune, TC on, three of us managed consistent 13.82's at 101/102 mph... My car and I weighed 4,500lbs... If anything, just go have fun, get a baseline and then make runs after each modification.

Regards,

Maurice

Re: Drag race tips (questions)

Posted: Thu May 17, 2018 8:40 pm
by SSpeedracer
I haven't tried in my caprice yet, but I'd start by running two tanks of E85 so fuel sensor triggers more aggressive timing.
Drop rear tire pressure. To what? IDK maybe 30psi, unless TPMS fault does something strange.

Why leave traction control on? Someone explain why that helps. What about sport mode?

Light up the tires to heat them and practice foot brake launches to figure out best RPM.


Its kinda gay, but race him from a roll like 20 or 30 or even 40 mph.

Re: Drag race tips (questions)

Posted: Thu May 17, 2018 8:58 pm
by Mooseman
TC is garbage for drag racing. My '11 can't be turned off so I have to pull the ABS fuse. The first couple of runs with it on, I got mid 15's. Off, dropped to mid 14's. (It's bone stock) What TC does is activate the brake to the slipping wheel(s) and pulls the throttle back, both of which you don't want.

Re: Drag race tips (questions)

Posted: Wed May 30, 2018 8:00 pm
by HoldenPPV
Regarding SSpeedracer‘s tip of running a couple tanks of E85 for a more aggressive tune...

Researching this angle made my head spin. On boosted motors there is a plain and simple HUGE gain in horsepower on dynos according to every single thing out there. On both boosted motors and NA engines there is a significant loss of fuel economy (which I could care less about, especially for this challenge).

Then the discrepcancies come in. On flex fuel motors that is. On “older” flex fuel vehicles (my ‘12 9C1 apparently qualifies as older) it seems that some say the engine computer gives no HP advantage using E85, it just bumps fuel flow volume up and timing enough to run exactly the same as using the recommended octane unleaded. But on newer flex fuel vehicles after about ‘14 both GM and Ford are claiming significant HP gains in their flex fuel engines using E85.

But this ‘older’ flex fuel engined vehicle angle is internet scuttlebutt and speculation by the usual type of seat of the pants dyno experts (except for the boosted engine and newer flex fuel applications, which appears to be well tested and documented).

So... no harm no foul I guess and run the E85 like SSpeedracer suggested?

Re: Drag race tips (questions)

Posted: Thu May 31, 2018 3:20 am
by HoldenPPV
Own question answered after a second search here on NewCaprice. There were so many hits on my first E85 search query, I just missed this gem of a link posted by xcidmigs back in 2015– viewtopic.php?f=9&t=2036&hilit=Michigan+test" onclick="window.open(this.href);return false; (it’s post #5).

https://www.michigan.gov/documents/msp/ ... 1027_7.pdf" onclick="window.open(this.href);return false; testing the 2011 police car offerings.

Thanks xcidmdigs for the link...

The 2011 Caprice clearly runs faster on E85. On average is about 2/10 faster at 0-100mph runs than itself on just plain gas. Even faster 0-100 than the police 5.7L Hemi Dodge Charger (on average) which is rated at 15 more HP and 13 ft lbs more torque than the L77. Probably because of it’s 2.65:1 axle ratio compared to the Caprice 2.92:1. My guess anyway since there is only 11lbs difference in the weight of the cars, the Caprice being heavier.

But my goal here is not to beat a retired police Charger. The Caprice will be pitted against a bone stock twin turbo i6cyl BMW 335i with 300hp/300ft.lbs. torque in a 700 lb lighter car.

I realize the physics here are not on my side, but hope springs eternal. I cut a good light, who knows? lol...

Re: Drag race tips (questions)

Posted: Thu May 31, 2018 10:43 am
by CrashTestDummy
Going to be tough. It looks like most 335i's run mid-to-low 13's in stock trim. Good luck, and it's going to take some practice.