Lorenzen's Progress Thread
#121
TECH Addict
iTrader: (2)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
So all the suspension components are stock, the rear shocks have maybe 25k on them as factory replacements and I don't know which cradle bushings its got in it.
#122
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
I inherited the cradle bushings in a cradle I swapped out of another v1 I purchased. That v was maggied, cammed, 8.8 etc but when the oil pump/cam/lifters went out, I took that complete rear cradle assembly with the 8.8 and swapped it as a complete dropout into my 05. The maggied V powered through the wheel hop I guess as it would leave posi marks as long as I stayed in it with no problem...the 05 just doesn't have the *** to do it.
So all the suspension components are stock, the rear shocks have maybe 25k on them as factory replacements and I don't know which cradle bushings its got in it.
So all the suspension components are stock, the rear shocks have maybe 25k on them as factory replacements and I don't know which cradle bushings its got in it.
Severe wheelhop occurs when the torque transient you're creating (by stomping on the gas) excites the natural (resonant) frequency of your rear suspension and subframe. Although your improved axles and bushings have some effect on that natural frequency, your springs and shocks (combined with the weight of your car) dominate the response.
Because your springs and shocks are super soft, the natural frequency of your rear end is very low. This puts your rear end in range of being excited when you try and accelerate. Increasing your spring rate and/or damper rate will push that natural frequency way up, higher than you can create with the gas pedal. I would focus on stiffening up the rear end and see where that takes you.
#124
TECH Addict
iTrader: (2)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
I have an observation. Apologies in advance--I have no idea how to translate this to non-engineering speak:
Severe wheelhop occurs when the torque transient you're creating (by stomping on the gas) excites the natural (resonant) frequency of your rear suspension and subframe. Although your improved axles and bushings have some effect on that natural frequency, your springs and shocks (combined with the weight of your car) dominate the response.
Because your springs and shocks are super soft, the natural frequency of your rear end is very low. This puts your rear end in range of being excited when you try and accelerate. Increasing your spring rate and/or damper rate will push that natural frequency way up, higher than you can create with the gas pedal. I would focus on stiffening up the rear end and see where that takes you.
Severe wheelhop occurs when the torque transient you're creating (by stomping on the gas) excites the natural (resonant) frequency of your rear suspension and subframe. Although your improved axles and bushings have some effect on that natural frequency, your springs and shocks (combined with the weight of your car) dominate the response.
Because your springs and shocks are super soft, the natural frequency of your rear end is very low. This puts your rear end in range of being excited when you try and accelerate. Increasing your spring rate and/or damper rate will push that natural frequency way up, higher than you can create with the gas pedal. I would focus on stiffening up the rear end and see where that takes you.
IMHO the problem is with the location of the front mounts. It's too close to the centerline of the axle and it doesn't have the leverage needed to hold the cradle firmly in place.
#125
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
I don't think I can get it much stiffer than capturing the front of the cradle and bolting it down solid. See post above for further description.
IMHO the problem is with the location of the front mounts. It's too close to the centerline of the axle and it doesn't have the leverage needed to hold the cradle firmly in place.
IMHO the problem is with the location of the front mounts. It's too close to the centerline of the axle and it doesn't have the leverage needed to hold the cradle firmly in place.
#126
TECH Addict
iTrader: (2)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
I'm a trashy 3rd gen v1 owner and can't afford to throw 3k at the car on a bunch of cool parts that will make the car handle a little better when, for 30 bucks and a days work, I can make a reasonably good attempt at stabilizing the cradle instead.
![Cheers!!](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_cheers.gif)
Reading the thread, you'll see I already made an under-car attempt at capturing the cradle from the front trailing arm mount and while it worked at managing wheel hop, I pulled them off due to pinion angle and ground clearance issues. While those were on the car, I didn't notice any appreciable increase in road/diff noise so I'm keeping my fingers crossed here.
I'd love to have a set of KWs but I also appreciate the self leveling feature of the factory units as I tow a motorcycle trailer, haul tools for work and, unfortunately, most of my friends weigh 250 each.
#127
On The Tree
Thread Starter
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Continuing on -- I finally picked up a new air filter as the one the car came with was scareweed. I wonder if I can consider this to be a "Performance Upgrade" lmao.
![Name: 20160706_203601_zpsahvfwt6n.jpg
Views: 31
Size: 319.2 KB](https://ls1tech.com/forums/attachments/cadillac-cts-v-2004-2007-gen-i/627318d1501381345-lorenzen-s-progress-thread-20160706_203601_zpsahvfwt6n.jpg)
The Kars III Kit also came in today. Pretty excited to get this put in this weekend. I'm tired of this car feeling like a spaghetti noodle. I've yet to figure out why, but my 06 base I had was more confidence inspiring in the corners than this car is currently.
![Name: 20160706_201659_zpsw75xf3np.jpg
Views: 43
Size: 267.3 KB](https://ls1tech.com/forums/attachments/cadillac-cts-v-2004-2007-gen-i/627319d1501381345-lorenzen-s-progress-thread-20160706_201659_zpsw75xf3np.jpg)
Any input from the peanut gallery if it's better to brace the diff with the Kars or the bmr? Both? Neither?
To me. BMR>Kars>neither>both. Reason for me is the bmr is to an existing mount the differential is already using. I don't see adding in another mount that isn't mounted the same being beneficial. Also, using both seems like one would add stress on the other. I'm open for debate on this. It's a gen4...might as well be the first to break one haha.
![Name: 20160706_203601_zpsahvfwt6n.jpg
Views: 31
Size: 319.2 KB](https://ls1tech.com/forums/attachments/cadillac-cts-v-2004-2007-gen-i/627318d1501381345-lorenzen-s-progress-thread-20160706_203601_zpsahvfwt6n.jpg)
The Kars III Kit also came in today. Pretty excited to get this put in this weekend. I'm tired of this car feeling like a spaghetti noodle. I've yet to figure out why, but my 06 base I had was more confidence inspiring in the corners than this car is currently.
![Name: 20160706_201659_zpsw75xf3np.jpg
Views: 43
Size: 267.3 KB](https://ls1tech.com/forums/attachments/cadillac-cts-v-2004-2007-gen-i/627319d1501381345-lorenzen-s-progress-thread-20160706_201659_zpsw75xf3np.jpg)
Any input from the peanut gallery if it's better to brace the diff with the Kars or the bmr? Both? Neither?
To me. BMR>Kars>neither>both. Reason for me is the bmr is to an existing mount the differential is already using. I don't see adding in another mount that isn't mounted the same being beneficial. Also, using both seems like one would add stress on the other. I'm open for debate on this. It's a gen4...might as well be the first to break one haha.
Last edited by tlorenzen; 07-07-2016 at 06:00 AM.
#129
TECH Junkie
iTrader: (3)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Looks like your filter went through a similar experience to mine once. The body shop had stuck a plastic bag over the filter during some process of repair and started the car without removing it. It sucked the filter into the same shape and they replaced it.
I've recently been going through my rear suspension for the same lack of confidence that you're experiencing. The biggest improvements have been with the poly cradle and trailing arm bushings. Also make sure your bolts are tight, tight, tight. I still think one of my toe rods needs to be replaced as I'm getting a little brake shimmy from my PSR wheel. I have a set of rear upper control arms in the box that I haven't gotten around to installing yet and wish I had during the cradle bushing install since the cradle has to come down to remove them.
I also had some good improvements from the front lower control arm bushings that I replaced with Creative Steel's street hardness. I like that they're greaseable because I've had problems with squeaky poly before that was a big pain to deal with.
I've recently been going through my rear suspension for the same lack of confidence that you're experiencing. The biggest improvements have been with the poly cradle and trailing arm bushings. Also make sure your bolts are tight, tight, tight. I still think one of my toe rods needs to be replaced as I'm getting a little brake shimmy from my PSR wheel. I have a set of rear upper control arms in the box that I haven't gotten around to installing yet and wish I had during the cradle bushing install since the cradle has to come down to remove them.
I also had some good improvements from the front lower control arm bushings that I replaced with Creative Steel's street hardness. I like that they're greaseable because I've had problems with squeaky poly before that was a big pain to deal with.
#130
On The Tree
Thread Starter
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Interesting... I was thinking it got crushed cause the crappy k&n barrier was unbolted when I got the car. It only took me 8 months to get around to replacing it haha. Although I didn't notice any difference in power or response with the new one.
I did the Revshift 95A rear cradle bushings and they made a nice difference, but still not where I want the car to be. They also have a tendency to make popping noises. I will be going CS for the arms, toes etc. for the same reason being they're greaseable. Another maintenance item to worry about but if I can confidently take some sweepers with some bumps in them at 80 I'll be satisfied.
I did the Revshift 95A rear cradle bushings and they made a nice difference, but still not where I want the car to be. They also have a tendency to make popping noises. I will be going CS for the arms, toes etc. for the same reason being they're greaseable. Another maintenance item to worry about but if I can confidently take some sweepers with some bumps in them at 80 I'll be satisfied.
#131
TECH Junkie
iTrader: (3)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Put a torque wrench or breaker bar on those cradle bolts. They need to be tight. I forget the specs offhand but they're somewhere around 100lb-ft I didn't get them tight enough the first time and had a similar result. Another pass of tightening made them feel much better.
#132
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Put a torque wrench or breaker bar on those cradle bolts. They need to be tight. I forget the specs offhand but they're somewhere around 100lb-ft I didn't get them tight enough the first time and had a similar result. Another pass of tightening made them feel much better.
Last edited by FuzzyLog1c; 07-07-2016 at 04:34 PM.
#135
On The Tree
Thread Starter
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Damn, I got them about as tight as I could with my breaker bar. Didn't want to snap a bolt. I'll have to check and see if my torque wrench even goes up to 195 ft-lbs.
I will check it out this weekend when I put the Kars kit on.
I will check it out this weekend when I put the Kars kit on.
#138
TECH Addict
iTrader: (2)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Nice call Bud...
I'd research the pinion brace setup as I could have sworn some of them broke as many diffs as it helped. Beyond that, directly bolting the brace to the diff and then bolting it directly to the chassis of the car has the potential to be way noisy. If it were mine, i'd cut the pinion support off and then bolt it to the car.
I'd research the pinion brace setup as I could have sworn some of them broke as many diffs as it helped. Beyond that, directly bolting the brace to the diff and then bolting it directly to the chassis of the car has the potential to be way noisy. If it were mine, i'd cut the pinion support off and then bolt it to the car.
#139
#140