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      10-28-2024, 02:21 PM   #397
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Originally Posted by Jnat View Post
Reporting back that after doing some rather aggressive driving and launching this weekend, all is well with the new set up (Clint's doughnut and the Bellmetric bolt). Originally i was going to frequently change the bolt but it's fine and i'm gonna leave this one in there for the time being. Up until now i've not been launch crazy but now i'm adjusting the XHP setting's for launch and trying to dial it in. I can say that with 305' width 21's out back i had quite a bit of wheel spin and hop but still managed two back to back 3.02 0-60's and a 7.1 1/8 mile on draggy. Unfortunately i had to come out of it before even the 1/8th due to road conditions. I'm gonna lower air pressures and see what that does to try and improve traction on the street. Would love to post some pic's but haven't been able to figure that out.
I am also dealing with a lot of wheel hop on PS4Ss when road temps were high. I've cut a 2.83 0-60 (2.62 w/RO) but most are in the 2.9 range. Putting my winter tires on soon, will try again. It's probably better with a little spin.
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      10-28-2024, 06:06 PM   #398
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Originally Posted by foxdie262 View Post
I am also dealing with a lot of wheel hop on PS4Ss when road temps were high. I've cut a 2.83 0-60 (2.62 w/RO) but most are in the 2.9 range. Putting my winter tires on soon, will try again. It's probably better with a little spin.
A little spin i agree with but the hop bothered me and isn't good for anything...
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      10-28-2024, 07:23 PM   #399
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Quote:
Originally Posted by foxdie262 View Post
I am also dealing with a lot of wheel hop on PS4Ss when road temps were high. I've cut a 2.83 0-60 (2.62 w/RO) but most are in the 2.9 range. Putting my winter tires on soon, will try again. It's probably better with a little spin.
Lots of cars experience wheel hop & it's fairly common. Lower your tire pressures a touch & that should help with more bite. Once the PS4S tires, or any tire for that matter get warm, they tend to get grippier because they become more pliable. I would not be comfortable with lots of wheel hop too.
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      10-29-2024, 05:36 AM   #400
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Originally Posted by Kevin_The_Clean1 View Post
Lots of cars experience wheel hop & it's fairly common. Lower your tire pressures a touch & that should help with more bite. Once the PS4S tires, or any tire for that matter get warm, they tend to get grippier because they become more pliable. I would not be comfortable with lots of wheel hop too.
Lowering the air pressure in the rear is my next move, i'll report back how that works out. I have to say i was a little surprised that i had as much wheel spin and hop with the 305 that i did... interested to hear anyone running 305 width on 20s or 21s if they experienced the same.
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      10-29-2024, 09:57 AM   #401
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Originally Posted by Jnat View Post
Lowering the air pressure in the rear is my next move, i'll report back how that works out. I have to say i was a little surprised that i had as much wheel spin and hop with the 305 that i did... interested to hear anyone running 305 width on 20s or 21s if they experienced the same.
With the torque these cars produce they'll spin just about any tire. I've roasted all 4 with my Nitto NT555R2 drag radials and that was 275/315.

Managing the torque is the key. Lower RPM launch, making sure you have adequate tire pressure, finding a road that can keep traction. A lot of people don't understand that the surface you launch on greatly affects your times. Not all roads are created equal.
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      10-29-2024, 01:40 PM   #402
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Originally Posted by BrockDM View Post
With the torque these cars produce they'll spin just about any tire. I've roasted all 4 with my Nitto NT555R2 drag radials and that was 275/315.

Managing the torque is the key. Lower RPM launch, making sure you have adequate tire pressure, finding a road that can keep traction. A lot of people don't understand that the surface you launch on greatly affects your times. Not all roads are created equal.
Agreed...
What rpm are you thinking? I lowered the launch control adjustment in xhp by 11% (set launch torque) and the result is as stated. I let the flags come up and i'm thinking released at about 2750rpm.
Also, i'm running like 36-38 lbs of air in 305/21 Pzero's.
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      10-29-2024, 03:09 PM   #403
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Originally Posted by Jnat View Post
Agreed...
What rpm are you thinking? I lowered the launch control adjustment in xhp by 11% (set launch torque) and the result is as stated. I let the flags come up and i'm thinking released at about 2750rpm.
Also, i'm running like 36-38 lbs of air in 305/21 Pzero's.
I launch at 2800rpm. That seems to be the sweet spot. You can try lower or in xhp pull a little more torque out of the launch.

36-38 psi is too high of pressure and will never dead hook. Ideally you want to be around 28-30 for maximum traction during a launch. Pzero doesn't help the matter either unfortunately so you man need to pull even more torque out in xhp
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      10-29-2024, 04:03 PM   #404
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Originally Posted by BrockDM View Post
I launch at 2800rpm. That seems to be the sweet spot. You can try lower or in xhp pull a little more torque out of the launch.

36-38 psi is too high of pressure and will never dead hook. Ideally you want to be around 28-30 for maximum traction during a launch. Pzero doesn't help the matter either unfortunately so you man need to pull even more torque out in xhp
Figured that, i'll report back, thanks!
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      10-30-2024, 04:19 AM   #405
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Quote:
Originally Posted by BrockDM View Post
I launch at 2800rpm. That seems to be the sweet spot. You can try lower or in xhp pull a little more torque out of the launch.

36-38 psi is too high of pressure and will never dead hook. Ideally you want to be around 28-30 for maximum traction during a launch. Pzero doesn't help the matter either unfortunately so you man need to pull even more torque out in xhp
Brock, are you saying 28-30psi on all tires, or just rears?
I am a total noob at drag racing but it sounds like fun.
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      10-30-2024, 04:27 AM   #406
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Got my car back from the workshop today.
Rennfix doughnut + Belmetric hardware installed at ~52,411 miles.
I observed no apparent sounds or clunks on the drive home.
I will report back after putting some miles on it.

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      10-30-2024, 10:26 AM   #407
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I removed the two front diff bolts completely, two exhaust hangers and used two sets of hands along with a pry bar to get the doughnut past the ear. It took some maneuvering and a Deadman jack under the diff to get that doughnut in. The bolt obviously just slides in.
Went at it last night but was time constricted, finishing it up today. Which way did you pry? Pulled down on the diff or away (towards front of the car) ? Did a quick attempt last night and didn’t remove the front 2 diff bolts and wasn’t able to get enough room to squeeze the donut in so I’ll run to get a bigger pry and try again.
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      10-30-2024, 10:41 AM   #408
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Originally Posted by P3NS View Post
Went at it last night but was time constricted, finishing it up today. Which way did you pry? Pulled down on the diff or away (towards front of the car) ? Did a quick attempt last night and didn’t remove the front 2 diff bolts and wasn’t able to get enough room to squeeze the donut in so I’ll run to get a bigger pry and try again.
Skip trying to pry it down - just pull the front bolts and save yourself the headache. I tried with three different prybars and couldn't get it to move far enough to slip the bush in. Maybe it was just me working under my car on jackstands, but after I pulled the front bolts, gently lowering the diff was cake and the bushing slipped in easily. Reverse was easy too.
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      10-30-2024, 10:42 AM   #409
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Brock, are you saying 28-30psi on all tires, or just rears?
I am a total noob at drag racing but it sounds like fun.
I usually do a little less in the rear than up front as the awd system is still rwd bias in 4wd. The weight transfers most of the load over the rear too. Id try 32 front and 29 rear to start
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      10-30-2024, 01:14 PM   #410
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Originally Posted by foxdie262 View Post
Skip trying to pry it down - just pull the front bolts and save yourself the headache. I tried with three different prybars and couldn't get it to move far enough to slip the bush in. Maybe it was just me working under my car on jackstands, but after I pulled the front bolts, gently lowering the diff was cake and the bushing slipped in easily. Reverse was easy too.
Yep , there’s no way to pry without removing the other 2 bushing bolts. They weren’t easy to remove with the metal shielding there but I managed to get them out. Used a bottle jack and a rubber jack pad to support and lower the diff. The donut doesn’t go into the hole all the way, at least mine didn’t. So I used a mallet and tapped it in as much as possible then used the pry bar to get the diff past it and maneuvered the front 2 mount points to bolt them back up (all fits back together really tight, which is good but a little tricky to reassemble if your solo). I recommend sliding the bolt into the rear (donut mount) first to support and make it easier to realign the front 2 bushings.
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      10-30-2024, 05:19 PM   #411
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Originally Posted by P3NS View Post
Went at it last night but was time constricted, finishing it up today. Which way did you pry? Pulled down on the diff or away (towards front of the car) ? Did a quick attempt last night and didn’t remove the front 2 diff bolts and wasn’t able to get enough room to squeeze the donut in so I’ll run to get a bigger pry and try again.
I'm lucky as i have access to a lift and another set of hands. With that said i removed the two front diff bolts to make it easier.
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      10-30-2024, 05:20 PM   #412
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Originally Posted by P3NS View Post
Yep , there’s no way to pry without removing the other 2 bushing bolts. They weren’t easy to remove with the metal shielding there but I managed to get them out. Used a bottle jack and a rubber jack pad to support and lower the diff. The donut doesn’t go into the hole all the way, at least mine didn’t. So I used a mallet and tapped it in as much as possible then used the pry bar to get the diff past it and maneuvered the front 2 mount points to bolt them back up (all fits back together really tight, which is good but a little tricky to reassemble if your solo). I recommend sliding the bolt into the rear (donut mount) first to support and make it easier to realign the front 2 bushings.
This...
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      10-30-2024, 05:33 PM   #413
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I'm lucky as i have access to a lift and another set of hands. With that said i removed the two front diff bolts to make it easier.
I have a quick Jack that I modified using 2x4s for the longer Jack points of the x3. So it wasn’t the worst but definitely a lot easier using a 2 post lift and working standing up for leverage being these nuts and bolts are tight.
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      10-30-2024, 07:18 PM   #414
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I have a quick Jack that I modified using 2x4s for the longer Jack points of the x3. So it wasn’t the worst but definitely a lot easier using a 2 post lift and working standing up for leverage being these nuts and bolts are tight.
Absolutely...
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      10-30-2024, 08:56 PM   #415
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Originally Posted by BrockDM View Post
I usually do a little less in the rear than up front as the awd system is still rwd bias in 4wd. The weight transfers most of the load over the rear too. Id try 32 front and 29 rear to start
Dragy ordered.
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      10-31-2024, 06:48 AM   #416
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This...
Did you reuse the front diff bolts or buy new (if bought new by chance do you have the Belmetric part numbers)

Thanks

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      10-31-2024, 08:56 AM   #417
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Did you reuse the front diff bolts or buy new (if bought new by chance do you have the Belmetric part numbers)

Thanks

Jeff
I re-used them as i don't believe they are one time use bolts.
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      11-02-2024, 12:20 AM   #418
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Looks to me that the easiest thing to do is drop the muffler enough for you to get wiggle room.


Also, how the hell did he manage this? Is this stock? He's got pre-LCI non comp. I dont have that on my stock LCI...

Every x3m has 4wd and 4wd sport. You can only access 4wd sport if you are using either MDM or DSC OFF. If you have DSC ON, 4WD Sport will not be an available option.
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