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Just built and installed my 426... now I have traction problems...... lets talk

7K views 42 replies 19 participants last post by  MadTunes Racing 
#1 ·
Hi guys,

I just completed a 426 build for my jeep. It's a mild setup on the spec sheet but is causing some significant traction issues on the street. It spins all four from a low speed roll and completely fries them from a dig. It seems to do better leaving the traction control on which is the opposite of what I used to do with the little boy cam only setup. When the jeep spins the tires in first it usually short shifts into second and may even throw the p700 code if you leave the traction control off. It has been pretty cool lately and I know it will hook better when the weather is good but I wanted some input from others. This is the first time I've "confused" the tcm by spinning the wheels. I'm sure it would do much better with some drag radials on the rear but I really just wanted to hear what other jeeps with massive torque are doing for traction and how the tcm and transmissions are working with this hp level keeping the drivetrain mostly stock.

On a side note, I'm also debating on either installing blue top solenoids or getting the mopar tcm first. I want to keep the car "stock like" when easing around in it and am a bit worried about excessively harse downshifts with the blue tops.
 
#3 ·
I've heard that Paramounts TCM and valve body play nice together on a stock trans and it won't shift until it hits its shift point. Might be worth contacting Bill. His TCM with my D1 Procharger still caused short shifting but it was like at 5900 or better rather than 4000 ish. As for the massive 426 torque you are experiencing I can't comment on that from lack of stroker experience.


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#5 ·
If your on a stock trans get blue tops or preferably a BB vavle body. I say the VB cause if you need a new trans he will subtract the initial cost off the new trans. The jeeps tend to short shift into second with lots of tire spin, its pretty common. Also mine roasts the tires on the street as well. If you have a mild build you may not need a TCM. The TCM is used to raise shiftpoints and if you have a mild build you may not need the extra rpm
 
#6 ·
I'll probably eventually upgrade the entire trans but I'm not planning that for a while if I can help it. Doesn't the bb valve body have blue tops in it? I'm probably going to pass on the valve body for now as I'd rather spend that money once if I end up needing the entire trans done. How harsh is the downshift when just easing along and coming to a stop with blue tops installed? Will it tick off a wife? :)

Thanks for the replys.

Oh and tug: I'm running nitto 420s. What tires are you running and how does it hook in the summer from a dig on the street?
 
#22 ·
Lets say that the Blue tops will not pass the wife test for sure... The Jeep will downshift so harsh and will feel like someone but you from behind on the 2nd to 1st gear shift... Not a pleasant feeling as to why ai got rid of them.... I would get the Stage 2 Valvebody from Bill and it drives much better IMO...
 
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#9 ·
In the summer I was on a bad OEM 6.1L (torn ring land), I was pissed and needed a relief so I left my buddies Harley shop and went home to get the Jeep to blow off some steam and return to the shop. I laid 100'+ of rubber in the alley on new Crapyear's in about 88* of sunny weather on blacktop, in 2nd gear! Lol!


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#11 ·
Yes it's the stock rear. I understand that it is "peg legged" but the awd setup worked well enough with the cam only setup. What's the most economical way to install a lsd setup that will work well. I realize there are 5000.00 complete rear replacements but was curious about upgrading the stocker.
 
#12 ·
Wavetrac makes a front and rear LSD for these rigs, we sell a ton of them here. The majority of the guys here that are making good power have the rears and a handful of them have the fronts as well. You don't need a complete rear 5k replacement to have an LSD, all you need is the wavetrac and a shim kit with fluids/labor and you're set, they go for $1295+sh and $75 for the shim kit, we sell the combo for $1225 shipped, save you about $175 bucks through us
 
#13 · (Edited)
I think you guys are missing the point here.....

It's a traction problem, Not his tranny, valvebody, or TCM

If you want traction you need to do 2 things.......

1) Soft Drag Radials

2) Get power to BOTH rear tires...The 1 wheel peel isn't doing jack shit.

Either a Wavetrac or Bills 8.8 rearend.

On a side note, Depending on where you live, It might be pretty cold out....If it's cold out where you live say goodbye to traction till the weather warms up.

I can roast my tires in 3rd gear in this weather.

You are short shifting because you're spinning so bad and bouncing off the rev-limiter, it shifts into 2nd gear and BOGS....

All you need are the 2 things mentioned above + a warm street and warm tires...You will find traction.
 
#16 ·
Here's an example of getting traction...

Warm weather

Drag Radials

8.8 Rearend

1300 HP...Launching on 5#boost on a 2step and tranny brake

One chirp and gone

If I can get traction so can an NA 426 build

1BAMFR Solo Pass - YouTube
Of course I can set it up to get traction. I was just curious how well the stock setup was working with around 450 rwhp. I build drag setups in the ls world all the time but this is the first awd mopar that I have built and was just wanting to discuss a few things with you guys. And I am the one who was asking about transmission stuff to begin with. Got tired of searching and just wanted an open discuss. Thanks for your input. Nice setup you have there too. I built my engine with 10.3 to 1 compression with thoughts of maybe adding a procharger with around 8 lbs of boost. I certainly will need a ton of drivetrain mods before going that route. This build is meant to be fun with AWESOME street manners and the ability to go high elevens on the track. The older I get the more I tend to gravitate towards "drivablilty, street manners, and reliability" first and performance second. In my opinion, it's an art to build a ride in this way and have it perform well too. If your goal is to go fast and it doesn't matter if it surges, bucks, is loud, rides rough, gets crappy economy, has a rear end that whines etc. it's a lot easier to build it..... just takes cash and research.
 
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#20 ·
If you haven't already, PM BuilderBill from Paramount Performance and tell him what you're looking for. He can adjust the line pressures on his Stage II valve body to reduce the hard downshifts you're trying to avoid. Until you're in a position to purchase an aftermarket transmission, a valve body and TCM from Paramount Performance would take care of most of your immediate needs. A Wavetrac LSD for the rear along with a softer tire compound (i.e., Nitto NT05) will help even more.

Good luck!
.
 
#21 ·
Keoni, do you still daily drive the jeep. Or is it a weekend warrior. Also if you are just cruising around what kind of mpg do you get? BTW, your jeep is bad ass, I remember when you were running 11's because of traction and other issues, but to see it now it is very impressive. Very impressive:)
 
#25 · (Edited)
I dont daily drive it, you absolutely could, i just chose not to so i can keep it in mint condition. In the winter it sits and in the spring, summer, fall I drive it alot. The thing drinks gas like crazy....it probably gets 200 miles per tank. It really drives like an NA jeep till you start laying into it and the turbo starts to spool, then its hold on time.

Oh yeah man, I had major traction issues with the Vortech blower and the 393 motor. Tires and a rear put that to rest pretty easily! Its pretty much a dead hook every launch. Stage6 has my 2step dialed in perfectly.

I did have issues at ATCO this year and broke some teeth off the rear gears but that was due to wet tires, a hard launch, and pedaling the throttle.
 
#23 ·
regarding the spinning. sometimes a p700

Can it be normal to throw a p700 when you spin really bad in first, and then short shift into second staying in it. Mine has done it a couple of times when I was experimenting. It only does it when I experience a significant loss of traction and the tranny gets "out of sync" with the shift points. The trans is holding the gears fine as long as you don't nail it from too slow of a speed.
 
#24 ·
Something as simple as getting better tires will help with your traction. A set of 275/315 would work much better IMO. The 420's are nice, but adding the wider set up will give you a much bigger footprint.
 
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#30 ·
I have a small speedshop and I mostly work on gm. This was my first mopar stroker build. I'm about ready to change the break in oil and get it on the dyno for the final dial in and I'll post up a dyno results thread. I sourced most of my parts from RDP Motorsports in Ohio. "Dyno Steve" is helping me with the tuning as I don't do CMR at my shop (not enough dodge folks here for me to invest in the software just yet).

I had a little boy cam only setup before and had a bad lifter which caused the cam to seize and break the dowel off the front. It then bent 6 valve :(.... The rotating assembly was reuseable but I chose to go ahead and do a fully forged stroker kit. I used manley pistons, rods, and crank. I had a friend at a machine shop hand port the heads. We hand ported the throttle body and Intake manifold. I put ARP head studs and main studs in it with cometic gaskets. I decided to leave the factory exhaust manifolds on. I already had an SLP UD pulley which was helpful as it is cut for a keyway and the factory balancer is not. Went with a new mopar oil pump and lifters. Comp cams pushrods and springs. Cam is very small. 224/230 with a 114 lsa and about .570 lift. Compression is about 10.3 to 1. I wanted stock like compression for good n/a power and still be able to add some mild boost later. If I decide to build the trans, rear end, suspension, and upgrade the fuel system, I should have an easy 10 second ride that drives veryyyy stock like. Transmission and stall converter are still completely stock. My wife and I share the jeep and a supercharged 2004 Cadillac CTS-v for daily driving duties currently.... Later, I'll probably keep the jeep as my new drag car. (I had a n/a 404 iron block ls 1999 Transam that ran 10.7s on motor and was around 3800lbs race weight.... sold it last year)
 
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#28 ·
Your best bet is to add a mild twin turbo build on top of your stroker, that should solve the traction issues.

LOL but in all seriousness, your best bet is to use better tires or upgrade your rearend or other suspension components. Congrats on the new build and enjoy the power. I miss my stroker build. Best daily driver build ever!
 
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#32 ·
I appreciate the heads up.....I do have my own dynojet 248 with a wideband. I also have both hp tuners pro and the diablosport datalogging software. If I am not happy with the final a/f and spark advance, I'll make the necessary changes. :)
 
#34 ·
Ok, Well I'm not sure why there are such differing opinions; however, some people drive different than others. As long as it does not throw you into the windshield when regular driving and slowing down then it seems like a reasonable shot at doing what I need it to. I am going to try the blue tops first.

I will say that before the tranny re-learned the new power it was sluggish shifting between 2 and 3 but it is much improved now. I think this build may allow the tranny to last a good long time in n/a form and if the blue tops firm up the shifts.


Guys, I only wish we had the control that HP Tuners has over GM Transmissions. They have been saying they are going to support dx for the last 5 years. Maybe we will one day have it.

I also was reading about a product called the "Tranzformer" that LX people were using. Is that under development for the Jeep and is it any good?
 
#35 ·
Here is a stock driveline with DR's making about 650rwhp.




And this was done on NT05 Street tires making about 800rwhp. :D




In all seriousness though, it's gonna come down to your stall and tires. If you've got a big stall in your Jeep with a 426, you're gonna spin like nuts on the street without a good tire and I think the NT05 is about the stickiest street tire you'll find for the street unless you want to be like us and run a DR on the street.

Like you said to Keoni, you can build it to hook...... but right now it's all about tires and stall. I ran a 3700 stall in those videos but it was flashing in the low 4000's with the turbo. My best 60' time with a stock rear end and DR's was a 1.46. Low times can be had at the track.
 
#36 ·
Here is a stock driveline with DR's making about 650rwhp.

Jeep SRT8 Turbo runs 10.68@125 - YouTube


And this was done on NT05 Street tires making about 800rwhp. :D

Jeep SRT8 Turbo 10.51@129 - YouTube


In all seriousness though, it's gonna come down to your stall and tires. If you've got a big stall in your Jeep with a 426, you're gonna spin like nuts on the street without a good tire and I think the NT05 is about the stickiest street tire you'll find for the street unless you want to be like us and run a DR on the street.

Like you said to Keoni, you can build it to hook...... but right now it's all about tires and stall. I ran a 3700 stall in those videos but it was flashing in the low 4000's with the turbo. My best 60' time with a stock rear end and DR's was a 1.46. Low times can be had at the track.

I remember i saw your Jeep in the staging lanes at VMP years ago and said. Yup, thats what i want. This is the set up I had been waiting for.
 
#37 · (Edited)
http://www.facebook.com/#!/photo.ph...50801814.24811.100002584095142&type=1&theater



Here's a link to the dyno chart. I ended up getting a base file from Johan and I edited the wot a/f and spark on the dyno to dial it in. The other lines on the graph are from my LS6 CTS-V with maggie and long tubes. Check out how the hemi makes better mid-range numbers than the supercharged ls6. (fyi: the belt on the caddy slipped near the end of the pull or it probably would have hit 480+

I'm very pleased with how it drives and runs. I raced a friend's 12 model srt8 6.4 Challenger. He had drag radials, trinity tune, cai, and thermostat. He ran a 12.4 @ 111+ bone stock with only the radials. We ran after I installed his mods. From a 15 mph roll I pulled him to around 100 and then he held his ground but was not gaining. I was about 1.5 cars ahead at 115 when he gave up :) I also had some extra cargo in the back and a completely full tank of fuel so I am pretty optimistic that some 11.90s will be attainable with traction. I'm sure it would have been a worse kill if I would have ran from a dig. I'm rolling on the throttle with pretty good results off the line now.
 
#40 · (Edited)
Hand ported stock heads and a custom 224/230 cam at about .575 lift.. pretty much a baby cam for this size engine. Stock exhaust manifolds but we did some mild porting on the intake manifold. I was shooting for 440 rwhp and super nice manners. I was also hoping for 11.90s on the track. I think I will get that too. :)

Johan's base tune and a little warmer weather has helped out alot on traction. I think it might hook ok on the track.
 
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