LC32 Front Crossmember & Simple Engineering Front Stiffening Plate Drive Report

hdflstf · 05-11-2010, 09:37 PM

The Silver Rocket got the crossmember and stiffening plate installed today and went for a drive. Little did I know the drive would test all aspects of the new front end performance..but I digress.

The install was really pretty simple (from my view) the parts unbolt and bolt right in. About 30 to 40 minutes for 2 people using hand tools. A little more time for one person and maybe shave a little time with pneumatic tools. Easy enough, just be sure to tighten everything. The one big warning is that it is absolutely imperative that you get the front end alignment checked out one the install is complete since the 4 big bolts (2 each side) that locate the aft mount of the lower A-arms need to be removed thereby negating any previously done alignment work. This is only applicable to the crossmember upgrade and not the stiffening plate.

Initial test drive impressions:
First reaction is that the steering feels heavier (I'll discuss this in detail later). In general it felt like the frame was now stiff and the front suspension was doing the work instead of a mix of the two. Mine never really had a cowl shake issue so I can't say much about that but I expect this would have a positive impact since less of the bump in the road get transmitted to the body structure. The steering is much more definite and precise. Whereas any quick maneuver was met with a little delay as the rest of the SSR would follow the input, it is now an immediate change of direction.

The long drive:
Freeway onramp, full throttle acceleration, and cruising at freeway speeds was all fairly normal. The items that I did notice were that the tendency or the SSR to tramline on some of the freeway surface changes is reduced or eliminated. The need for small steering corrections related to road surface irregularities and or bumps has been all but eliminated (key point for later discussion). Managed to find a panic stop from ~75 down to ZERO (along with all the other traffic - smoking tires all around me - YIKES!

). SSR stopped really straight! No more little left and right kicks of the wheel to react to the road surface irregularities. Heart starts beating again.... Off the freeway and to my most hated bump in the world, there is just no good way to go through this thing without getting thrown around left and right. Slow, fast, straight through, at and angle - it just doesn't matter, it's still bad. This time, it was not nearly as bad as before not flat but 75% smoother than ever before! The one bump alone is worth the change.

Afterthoughts:
The heavy steering thing had me thinking all the way home. How could the crossmember change affect the steering to such an extent? So I got to thinking about what I felt. In all of the miles drive I can feel a definite difference in that the frame now feels like a separate entity from the front suspension so it is no longer part of the suspension flexing and twisting. Some of the turn with bumps, I can feel the suspension working and the frame holding steady instead of adding more compliance to the suspension. The other think I thought about was the lack of minor steering corrections I had to make while driving. Seems that the change has made the SSR go even straighter even while to road may be uneven and/or bumpy. it finally occurred to me that the steering was not heavier but since there was no longer a never ending series of bump induced feedback through the steering requiring constant small corrections, it just naturally seemed that the steering was heavier even though this is not the case.

I need to get the alignment checked and then I need to find an opportunity to go back and autocross it to see how it acts when pushed to the limit. All in all, the changes are an A++++ in my book.

Special thanks to 2005SSR6Speed and Mike in AZ.

MnMsToy · 05-11-2010, 09:48 PM

I agree special thanks to 2005SSR6Speed and Mike in AZ

OP · 05-11-2010, 10:13 PM

nice write up, thanks for the insight.

blznssr · 05-11-2010, 11:22 PM

Good critique and thoughtful conclusions; thanks.

smokey · 05-11-2010, 11:42 PM

After driving Mikes with the new crossmember I thought the steering felt heavier too. I have been looking forward to Arts input because I thought he would love the change. Great review and it is a change Im going to make on Smokey!!

RUN ROD RUN · 05-12-2010, 07:47 AM

Art, When you say "heavy steering" are you saying it takes more effort to turn lock to lock?

2005SSR6Speed · 05-12-2010, 09:37 AM

Quote:

Originally Posted by RUN ROD RUN

Art, When you say "heavy steering" are you saying it takes more effort to turn lock to lock?

The feeling of heaviness in the steering has been my concern with using the crossmember in your SSR.

My Girl Friend drove with the Crossmember in her TrailBlazer SS for over a week. She did not feel that the steering was heavier at all.

I spoke with Art about the concern with your SSR and really think it will be okay for you. Worse case senario would be that we have to pull it back out if it is a concern for you.

hdflstf · 05-12-2010, 11:26 AM

Quote:

Originally Posted by RUN ROD RUN

Art, When you say "heavy steering" are you saying it takes more effort to turn lock to lock?

Did you read my entire post??

Feels heavy as in harder to turn. In actuality, I think it is the same but the lack of nusiance steering feedback give the impression of it being heavier.

RUN ROD RUN · 05-12-2010, 12:25 PM

Quote:

Originally Posted by 2005SSR6Speed

The feeling of heaviness in the steering has been my concern with using the crossmember in your SSR.

My Girl Friend drove with the Crossmember in her TrailBlazer SS for over a week. She did not feel that the steering was heavier at all.

I spoke with Art about the concern with your SSR and really think it will be okay for you. Worse case senario would be that we have to pull it back out if it is a concern for you.

Thanks Joe.
That does seem strange that the TrailBlazer SS not feeling heaver steering then the SSR.
Wonder if it has something to do with the SS having a slightly longer wheelbase then the SSR (weight distribution)

2005SSR6Speed · 05-14-2010, 07:45 AM

Quote:

Originally Posted by RUN ROD RUN

Thanks Joe.
That does seem strange that the TrailBlazer SS not feeling heaver steering then the SSR.
Wonder if it has something to do with the SS having a slightly longer wheelbase then the SSR (weight distribution)

The comparison in the TrailBlazer SS/SSR steering feel was meant to show the differences between testers. Both vehicles feel very similar in driving characteristics.

LTs SSR · 05-23-2010, 06:05 PM

Well.. what can I say ... these tech sessions are dangerous!! Listened to Joe & Mike talk about the front stiffening plate... a wee bit later... Mike & I spoke a little.. and since my truck was ALREADY up in the air... told 'em to go for it...

I think Mike had a little too much fun... banging and drillin' on my truck...

Notice the ear protection provided by Umpire 13!!

So... took 'er for a spin.. & you know the little jiggle you get even pulling outta the driveway... there was NONE! It was stiff! But not hard if that makes any sense. It responded very well... Even steered it on the way home like this...

The road affected the steering less...

SO This morning... I got out and really tested it in the canyons.. twisty, turvey, switch back kinda road... and pushed it, I mean really pushed it. I really like the tightness of front end. There is much less jiggle in the steering wheel and it handles much nicer now. Only problem is now the backend feels a little sloppy... The tailend almost got away from me in one of the switch backs which hasn't happened since I lower it & put the rear swaybar on. Guess that will be the next thing... in the never ending pursuit of drivin' happy!

hdflstf · 05-23-2010, 06:55 PM

Managed to get some drive time with only the crossmember and then again with the crossmember and stiffening plate. Seat of the pants says the crossmember does about 35 to 40% and the stiffening plate does the rest in regards to tightening things up.
From a strictly handling perspective they are about 50-50.

Doug Allen · 05-23-2010, 08:03 PM

Quote:

Originally Posted by hdflstf

Managed to get some drive time with only the crossmember and then again with the crossmember and stiffening plate. Seat of the pants says the crossmember does about 35 to 40% and the stiffening plate does the rest in regards to tightening things up.
From a strictly handling perspective they are about 50-50.

Still surprised the new oil pan wasn't chromed.....

hdflstf · 05-23-2010, 09:49 PM

Quote:

Originally Posted by Doug Allen

Still surprised the new oil pan wasn't chromed.....

Maybe I can have you polish it in place during the next tech session.

Doug Allen · 05-23-2010, 09:52 PM

Planning, it's all about planning Rocket Man

hdflstf · 05-23-2010, 10:00 PM

Quote:

Originally Posted by Doug Allen

Planning, it's all about planning Rocket Man

True. If this was planned, it could have been chrome but now we'll never know for sure

Dicktator · 05-24-2010, 06:26 AM

Is the power steering ratio different between the Trailblazer and the "R"?

Is there a big difference in weight?

Just wondering if that would contribute to the difference in steering "feel".

Sounds like I need one, OK want one.

Dicktator

MnMsToy · 05-24-2010, 07:36 AM

Quote:

Originally Posted by hdflstf

Managed to get some drive time with only the crossmember and then again with the crossmember and stiffening plate. Seat of the pants says the crossmember does about 35 to 40% and the stiffening plate does the rest in regards to tightening things up.
From a strictly handling perspective they are about 50-50.

Rocketman, would you elaborate on the 50/50 handling perspective?

William · 05-24-2010, 07:50 AM

Quote:

Originally Posted by LTs SSR

Well.. what can I say ... these tech sessions are dangerous!! Listened to Joe & Mike talk about the front stiffening plate... a wee bit later... Mike & I spoke a little.. and since my truck was ALREADY up in the air... told 'em to go for it...

I think Mike had a little too much fun... banging and drillin' on my truck...

Notice the ear protection provided by Umpire 13!!

So... took 'er for a spin.. & you know the little jiggle you get even pulling outta the driveway... there was NONE! It was stiff! But not hard if that makes any sense. It responded very well... Even steered it on the way home like this...

The road affected the steering less...

SO This morning... I got out and really tested it in the canyons.. twisty, turvey, switch back kinda road... and pushed it, I mean really pushed it. I really like the tightness of front end. There is much less jiggle in the steering wheel and it handles much nicer now. Only problem is now the backend feels a little sloppy... The tailend almost got away from me in one of the switch backs which hasn't happened since I lower it & put the rear swaybar on. Guess that will be the next thing... in the never ending pursuit of drivin' happy!

What drilling needed to be done ?

Thanks

Mike in AZ · 05-24-2010, 08:00 AM

Quote:

Originally Posted by Dicktator

Is the power steering ratio different between the Trailblazer and the "R"?

Is there a big difference in weight?

Just wondering if that would contribute to the difference in steering "feel".

Sounds like I need one, OK want one.

Dicktator

Dick,

The TBSS has a slightly different steering rack. There is a very small difference from the outside..... not worth going into longewinded discussion. Doubtful if it is a different ratio, probably slightly different valving and orifices to change the "feel" from a marketing standpoint.

The steering in the "R" was tuned (valving, pressures and orifices) for a performance feel. There were about 4 different "tweaks" that GM made through the years of SSR production. All of them trying to slightly modify the steering feel and road feedback to the wheel.

Lots of outside variables that will effect feel a little too........ The TBSS is a couple hundred pounds lighter than the SSR, but has a much higher center of gravity. Body roll is different. Body stiffeness is different. Rear suspension is air bags on the TBSS. Wheelbase is slightly different. Front spindles are different.......

The front alignment is different in the TBSS and the SSR has 19" tires instead of the 20's on the TBSS. All in all, there is a lot of similarity, but enough difference that they don't handle or feel the same.

Yes, You need to get this.

Mikey

William - As for "drilling", we had to put two holes in the small metal transition between the two front crossmembers where the front of the plate attaches. It's the vertical surface directly below the crankshaft pulley. The 2006 already has holes there. We used the stiiffening plate as a template. What you see in the photo is me with an air hammer and Richard covering my ears. We had to tweak a bracket on LT's truck a little. Not a factor on anyone elses.

Mike

MnMsToy · 05-24-2010, 09:33 AM

"William - As for "drilling", we had to put two holes in the small metal transition between the two front crossmembers where the front of the plate attaches. It's the vertical surface directly below the crankshaft pulley. The 2006 already has holes there. We used the stiiffening plate as a template. What you see in the photo is me with an air hammer and Richard covering my ears. We had to tweak a bracket on LT's truck a little. Not a factor on anyone elses."

Mike, does that mean that most all of the 05s and 06s will need to be drilled?

William · 05-24-2010, 09:56 AM

What are the recommended torque values for the LC32 and plate bolts ?

Thanks

2005SSR6Speed · 05-24-2010, 03:41 PM

Quote:

Originally Posted by MnMsToy

"William - As for "drilling", we had to put two holes in the small metal transition between the two front crossmembers where the front of the plate attaches. It's the vertical surface directly below the crankshaft pulley. The 2006 already has holes there. We used the stiiffening plate as a template. What you see in the photo is me with an air hammer and Richard covering my ears. We had to tweak a bracket on LT's truck a little. Not a factor on anyone elses."

Mike, does that mean that most all of the 05s and 06s will need to be drilled?

Most if not all of the 2005-2006 SSR's already have the holes. The 2003-2004 SSR's are the ones that dont have the holes.

Quote:

Originally Posted by William

What are the recommended torque values for the LC32 and plate bolts ?

Thanks

The LC32 Crossmember uses all the factory torque specs.

hdflstf · 05-24-2010, 07:43 PM

Quote:

Originally Posted by MnMsToy

Rocketman, would you elaborate on the 50/50 handling perspective?

Sorry.. All I was trying to get at is that from a strictly handling perspective each component seems to contribute about half of the improved (perceived or likely real) handling. I need to autocross it to know for sure but it likes the freeway onramps even more and it doesn't feel like it's trying to eat the outside edge of the outside tire in the turn.

William · 05-25-2010, 10:00 AM

Quote:

Originally Posted by 2005SSR6Speed

Most if not all of the 2005-2006 SSR's already have the holes. The 2003-2004 SSR's are the ones that dont have the holes.

The LC32 Crossmember uses all the factory torque specs.

It says 177 ft.lbs. for the 4 large bolts in the service manual.

Is that correct ?
Thanks

jpaintmat · 05-25-2010, 02:04 PM

The Trailblazer bar across the 2 channels made all the difference in the world. Cowl shake is virtually gone. Best $50 you could do, a 10 minutes job.