What would you do...racing MJ

[rockwerks]

Well if your cheating and there cheating then obviously your all on fair ground
again. It becomes your knowhow and driving vs. theres thats what "stock" racing is. The reason for different coils on each side is because its an oval
track. You want the outside harder than the inside so the vehicle can turn easier and faster.

well its a fine line when working with vairing spring rates for an oval car....a couple # spring rate difference can caause massive over stear and on a mini truck that will be the case in the first place. ID leave spring rates the same and use rancho 9000's for adjustment...or ol skol 4 way adjustable coilover shocks.

dont forget you if you need to add weight do it over the rear axle under the bed

is this for dirt track or pavement

 

[xuv-this]

well its a fine line when working with vairing spring rates for an oval car....a couple # spring rate difference can caause massive over stear and on a mini truck that will be the case in the first place.

well said. but for shocks, go gas charged. bilsteins are great, monroes are pretty good. MABYE 1 rancho 9000 on the left rear to tweak the rubber comin' into the corner?

 

[John(XJ)Jeep]

well its a fine line when working with vairing spring rates for an oval car....a couple # spring rate difference can caause massive over stear and on a mini truck that will be the case in the first place. ID leave spring rates the same and use rancho 9000's for adjustment...or ol skol 4 way adjustable coilover shocks.

dont forget you if you need to add weight do it over the rear axle under the bed

is this for dirt track or pavement

Yeah that makes sense, I'd start screwing around with it. What better way to learn. Although I wonder if cutting the springs is allowed?

 

[yellowxj]

its 3/8 mile asphalt...figure/guessing the top speeds for the leaders will be about 65 mph peak(maybe a little less)...going to time them next Saturday...hoping not to have to change gearing. Third gear on a AX5 w/ 3.55 gears and 225/70r15 tires...anyone know what rpm we would be turning with that set up to hit 65mph??? Its going to take a while to find all the calculators to figure that out...
Whats peak HP and Torque #'s on a 86 tbi 2.5l...we want to run the torque peak out of the corners and try to get to peak hp by the end of the straightaway...

 

[yellowxj]

and springs should appear stock...figured the tj coil and xj coil are aweful close looking...

was looking at a celica that had been a leader out there, my friend just bought it...found all sorts of lead weights hidden on the drivers side...big chunk hidden in the drivers seat mount...would have been well covered by the racing seat....cheating bastards

 

[xuv-this]

and springs should appear stock...figured the tj coil and xj coil are aweful close looking...

was looking at a celica that had been a leader out there, my friend just bought it...found all sorts of lead weights hidden on the drivers side...big chunk hidden in the drivers seat mount...would have been well covered by the racing seat....cheating bastards

set that jeep up right and if you can get enough powerband, your rwd will drift like a ghost and smoke his @ss coming out of those turns. :repair:

 

[REDXJ4FUN]

its 3/8 mile asphalt...figure/guessing the top speeds for the leaders will be about 65 mph peak(maybe a little less)...going to time them next Saturday...hoping not to have to change gearing. Third gear on a AX5 w/ 3.55 gears and 225/70r15 tires...anyone know what rpm we would be turning with that set up to hit 65mph??? Its going to take a while to find all the calculators to figure that out...
Whats peak HP and Torque #'s on a 86 tbi 2.5l...we want to run the torque peak out of the corners and try to get to peak hp by the end of the straightaway...

well peeak hp is 117 at 5000 and peak torque of 135 at 3500. the 225 70 15 is a 27.4 in tire and 3rd gear is 1.45 so.
65mph with 3.55 is 4100 kind short of what your looking for but you peak torqe will be about 55 mph. if you drop to 4.10 ... 65 will be 4740rpm and peak torque will be about 47mph. i don't have a tach in my mj right now so i can't realy comfirm the peak power and where it realy starts to pull in 3rd gear. i know mine has 3.55 but i'm running a 235 75 15 an 3rd it pulls to 80 with out much of an issue and that is about 4800 an 80 mph in 5th is only 2800rpm no wonder it like to open up on the highway. and gets damn good miliage on the highway.

 

[yellowxj]

THANKS 4.10 sounds good on paper, thats a lot of math...think the goal for this truck is to have it ready by the middle of october...I'll try to take pics as we go...anyone else have ideas?

 

[racerdave]

If you cut the stock springs, use a saws all and not a torch. Get into the summit catalog and find the wedge plates for the R.Rear (SUM-770025, helps bite)
Mount your fuel cell on the right side of the truck, remeber on dirt you drive off the corner with the right rear tire, on pavement you drive off the corner with the left rear (same with the fuel cell) Keep your weight kinda high on a dirt car, you want it to roll over on the right more than the left so spring it soft and tune it with the shocks. (put zip ties on the shock shaft, do some laps and check the travel) Make notes on everything! Tacky track, air temp, tire pressure, etc. Does the track dry out at night...dryslick? If so set the truck up like you would a pavement car, even tho this is small stakes racing you want to win the Main, where the $ is so you can come back and race again next week. Race for the $! Let the ricers have the trophys!! Even poor boys like us who do their home work can come home winners on Sat nite.
Send us pictures!! :lecture:

 

[CommandoXJ96]

i wanna see some pictures too - of some MJ kicking some VW butt.

 

[John(XJ)Jeep]

Your top speed with AX5, 5000 rpm and 225/70-R15 tires would be:

With 3.55 gearing

1st - 30mph, 48kmh
2nd - 49mph, 79kmh
3rd - 80mph, 128kmh
4th - 115mph, 184kmh
5th - 145mph, 233kmh

With 4.10 gearing:

1st - 26mph, 42kmh
2nd - 43mph, 68kmh
3rd - 69mph, 110kmh
4th - 99mph, 159kmh
5th - 126mph, 201kmh

With 3.07 gearing:
1st - 35mph, 55kmh
2nd - 57mph, 91kmh
3rd - 92mph, 148kmh
4th - 133mph, 212kmh
5th - 168mph, 269kmh

I'm not sure if you want to put the wieght to the outside on a pavement course. I think that would make the vehicle unstable. Inertia wants to go to the outside so I think that putting whatever weight you can on the inside will do a much better job. I find that the point is to make the car as level as possible around the corners. Putting the weight of the fuel to the outside, mind you thats a lot of weight will make it roll too much to the outside putting a lot of pressure on the outside tires chewing them up and pushing you to the wall. It's allready a pickup so the backend will be light and cause to drift anyway.

 

[yellowxj]

Great...a 2nd for the 3rd gear to get us to speed/rpm best torque/hp balance...btw...does an ax4 have the same gear ratio's? I have one of those too...would that help us get a few more rpm's out of 3rd gear??? 69 is a little fast I think for the track...might leave us wanting power coming out of the corners...trick is to not have to shift gears...most 4 cyl class cars dont let off the gas except as they enter turn 3.
So would the ax4 give us a few more rpms with the 4.10's???

 

[John(XJ)Jeep]

Appearently I can't find any info on the gear ratios for that tranny. All the info I found were either for the automatic or was false info. I don't know if the auto uses the same gearing but i highly doubt that. I'd stick with the AX5 that and you will only be changing between 2nd and 3rd at the most. If your lucky and set it up right you might be able to keep it in third.

 

[yellowxj]

I found this real quick but it looks like the ratios are pretty much the same...Transmission gear ratios--big list.

 

[John(XJ)Jeep]

Doesn't give info on the aw4, just wondering if there info holds true. I'm sure it does but you know... theres always typos. :laugh3: