Turbo XJ-R ran 12.98 @ 100mph in the 1/4 mile!

[PseudoSport]

This past weekend was the $2013 Grassroots Motorsports Challenge. With the addition of traction bars, new intercooler, and more boost we managed a 12.98 @ 100 mph in the quarter! That’s over a second faster then what we did last year. Problem now is we maxed out the fuel pump and couldn’t run any more boost.

More pictures and videos from the Challenge on our page www.facebook.com/JeepXJR

 

[WB9YZU]

Good Start, but it appears to need tweaking.

Your target is an MJ I saw in the 90's running a normally asparted 4.0L engine which ran consistant 13.2s on a hot day. This was a NHRA "Stock" class. You should be able to push a forced induction into the 11's.

 

[rav]

can you give some more info on the traction bars?

 

[Dr. Dyno]

Awesome stuff. I'm also interested in the traction bars that you used. Do you have any pics?

 

[JEEPERDK]

if im correct, from looking at the picture, it looks like he has kaltracks bars on there. they use a bracket that bolts to the bottomof the leaf spring via the u-bolts and then has a another bracket further up the leaf spring. the two brackets are connected by a bar with adjustable heim joints on either end. you adjust the bar still the front bracket stop is tight against the leaf spring, then when the axle twists up the bracket on the axle pushes the bar forward which pushes the bumpstop in the forward floating leaf spring bracket harder on to the forward part of the spring making it harder for the axle to twist upward. only bumper about this is you have to have 5" or more of front suspension travel to get the full affect of the system.

my father runs this same setup on his 66 dodge dart that runs (as of right now) a 10.87 @ 122MPH with a 1.57 60 foot time. he also runs a jerico 4-speed with a machlod soft lock adjustable clutch with a dana 60 and 4.10 gears. the car hooks very hard on his 9" wide slicks (no tubing was done). the car hooks so well that it pulls the wheels off the line.

but i dont know if thats correct but thats what it looks like he's running to me

 

[PseudoSport]

Yes we pretty much made our own caltrac bars. We are already spring under in the rear so it was easy to weld brackets to the spring plate. If you want to know how they work check out this link:

http://www.hotrodsandhemis.com/Traction.html

We had our corner weights and took our best guess to calculate and draw instance center on the side of the jeep. We then made the brackets and bars to try and get as close as we could to it. Still a crap shoot with traction bars but we did the best we could.

Only change we made was to add a stopper (big bolt) between the unibody and pivot. We can adjust the bars for drag racing so the pivot contacts the spring then adjust them the other way so the pivot stopper is against the unibody so we don’t get axle wrap under braking. Our suspension travel is only a few inches anyway so we haven’t noticed the bars when autocrossing.

We were in a rush to finish the bars before we left for the challenge and I’m not sure if we have pictures of them being made. I’ll see if my teammate can take some of them installed this weekend.

 

[JEEPERDK]

one thing I remember from setting up my fathers dart, is the more parallel to the ground that the bars are, the better the affect will be for helping gain traction. also, having a front suspension that can provide 5" or more of suspension droop will also help with getting traction with a caltrac's suspension system.

 

[markw]

Nice, there's probably a couple tenths in that 60 foot time. Just playing with the 4 link on my olds we got it to drop from 1.9's to 1.6's with pulling the wheels. Some tuning could get you into the 12.5 range, especially if you're starving the motor. Fix that before you grenade it.

 

[Johnnie Walker]

Nice!
Shortly after I picked up my current heep, in stock form with 235/75s, I met up with some of my old Dakota buddies @ Sac Raceway for "Mopar Magic". My best time was 17.4 @ 76 MPH, in 4wd! Haha. I would like to do it again some day, especially after I throw in an LSx.

 

[PseudoSport]

Nice, there's probably a couple tenths in that 60 foot time. Just playing with the 4 link on my olds we got it to drop from 1.9's to 1.6's with pulling the wheels. Some tuning could get you into the 12.5 range, especially if you're starving the motor. Fix that before you grenade it.

We were launching in second because it was constant and easy to brake torque. That and we never got around to installing a tach and staring at our half ass shift light and shifting once was easier, lol.

Our best 60' was a 1.81 but we shifted late and had to lift a little and still ran a 12.99. I'm sure there is a bunch of time we're leaving on the table but before we go back to the track in the spring we need to do something about the fuel system and add a tach.

 

[MrShaft696]

nice run, good show for a brick on wheels

 

[urban yan]

Very nice indeed.