http://e30m3performance.com/my...y.htm
Substituting the weight and attachment points on the Q/J indicates that between 360-400 pounds of compression force can be applied to each outboard upper strut mount.
At 0.73 G this [weight transfer deforms the strut tower] and would decamber the loaded tire by 0.7 degrees guess this is why the chose that amount of static negative tire camber.
The newer Q 97 has a oem brace so that it could function with the less camber of the MacPearson struts.
Strut tower brace theory
is there any other nissan that we could adapt a strut bar from, possibly an adjustible one? are the bolt patterns on the upper strut mount standard across the nissan line at all? Many bars out there for sentra/300zx platforms, if those strut mount patterns are the same, at least the mounting point part could be used, with a custom bar made for the centre...
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Q45tech
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- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
You install the bar and tighten the nut forcing the strut towers apart [not much just a tiny amount......like a few thousands of an inch...........aluminum treads failed inside my bar after 4 years.
The 3/8" x 24 Steel treads on the hiem joint [rod end] are wierd and the 1 and 1/4" threaded length [this is the only length made in this size and thread] barely engages less than 3/8" of thread inside the bar...................lousy design but looks pretty.
I spend all day yesterday trying to find a 3/8-24 quicksert and all were too large in diameter to fit inside the tapered bar end!
Obviously steel rod end threads are stronger than aluminum threads in bar and the 300 - 400 pounds of force can strip the aluminum..........never heard of it before but few have the old design stillen strut bar brace.
Each Q will be slightly different as to the exact distance between the shock tower mounting bolts and the position of the engine/plenum's possible contact point......you need at least a 1" clearance so as the engine moves it doesn't bang against the bar should have a bend in it X---]______[---X
The 3/8" x 24 Steel treads on the hiem joint [rod end] are wierd and the 1 and 1/4" threaded length [this is the only length made in this size and thread] barely engages less than 3/8" of thread inside the bar...................lousy design but looks pretty.
I spend all day yesterday trying to find a 3/8-24 quicksert and all were too large in diameter to fit inside the tapered bar end!
Obviously steel rod end threads are stronger than aluminum threads in bar and the 300 - 400 pounds of force can strip the aluminum..........never heard of it before but few have the old design stillen strut bar brace.
Each Q will be slightly different as to the exact distance between the shock tower mounting bolts and the position of the engine/plenum's possible contact point......you need at least a 1" clearance so as the engine moves it doesn't bang against the bar should have a bend in it X---]______[---X
As the resident STB non-believer, I've got to add my $.02 on this one. That is an interesting analysis, but it pulls the deflection numbers out of thin air and interpolating to the Q45 would be impossible even if the M3 number were accurate since we have no idea how much the shock tower deflects compared to an M3 at various loads. Also, since a Q45 doesn't have a strut suspension, the loads are not going to be transfered to the top of the tower like they would on an M3, and even if it does deflect, location of the top of the shock has no effect on camber when there is an upper control arm, unlike a car with a strut suspension. The upper control arm on a Q mounts much lower on the tower (almost not even the tower at that point) and should be a lot less prone to deflection. I'd be VERY surprised if an STB resulted in a .7 degree change in camber while cornering.
Searching for "strut tower brace" on http://www.corner-carvers.com will turn up quite a few discussions, and the general conclusion from people who spend a lot of time and effort trying to make their cars handle better and go faster on racetracks is that they are just added weight, even on Mustangs, which are have wet noodles for a chassis compared to a Q45. If they help anything, they would help a Mustang. They are readily available for my track car that I have invested a lot of time and money in, and I don't have one.
If somebody really wants to see if it makes a difference, a good test would be to do some skidpad laps with and without the STB. If it really does reduce deflection and cause a significant difference in camber while cornering, front tire temperatures would reflect that. A .7 degree change in camber could easily cause a 20-30F change in tire temps. (The inside edge of the tire would gain temperature and the outside would lose temperature with the STB on if it does anything). I'm betting it wouldn't.
Searching for "strut tower brace" on http://www.corner-carvers.com will turn up quite a few discussions, and the general conclusion from people who spend a lot of time and effort trying to make their cars handle better and go faster on racetracks is that they are just added weight, even on Mustangs, which are have wet noodles for a chassis compared to a Q45. If they help anything, they would help a Mustang. They are readily available for my track car that I have invested a lot of time and money in, and I don't have one.
If somebody really wants to see if it makes a difference, a good test would be to do some skidpad laps with and without the STB. If it really does reduce deflection and cause a significant difference in camber while cornering, front tire temperatures would reflect that. A .7 degree change in camber could easily cause a 20-30F change in tire temps. (The inside edge of the tire would gain temperature and the outside would lose temperature with the STB on if it does anything). I'm betting it wouldn't.
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Q45tech
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1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Your missing the point the whole shock tower metal work bends, the upper link rear mount bolts to the shock tower metal work so this is where the stress is.
All I can say is I installed a load cell [strain gauge] between the rod end and the bar ........something is causing a deflection and the load variance >340 pounds.
Why did Nissan waste money on oem front unit on all 97-02Q?........definitly not for looks cause they chose a functonal bar.
Actually the bar helps dampen the tire/road vibrations by rigidizing the body!
All I can say is I installed a load cell [strain gauge] between the rod end and the bar ........something is causing a deflection and the load variance >340 pounds.
Why did Nissan waste money on oem front unit on all 97-02Q?........definitly not for looks cause they chose a functonal bar.
Actually the bar helps dampen the tire/road vibrations by rigidizing the body!
A couple of things. Are you measuring deflection or just load? Those towers are built out of very beefy metal and are designed to see serious loads. Second, even if the top of the shock tower is deflecting, the upper control arm attachment point (which is what matters on a car with an upper control arm) isn't deflecting as much since it mounts lower in the tower at a point that almost isn't even the "tower" anymore. I'd guesstimate the attachment point is a good 6-6.5" below the top of the tower.Q45tech wrote:Your missing the point the whole shock tower metal work bends, the upper link rear mount bolts to the shock tower metal work so this is where the stress is.
All I can say is I installed a load cell [strain gauge] between the rod end and the bar ........something is causing a deflection and the load variance >340 pounds.
Quote »Why did Nissan waste money on oem front unit on all 97-02Q?........definitly not for looks cause they chose a functonal bar.[/quote]
Probably because the 97-01 cars use struts, and if a STB is useful for anything, it would be on a strut equipped car, since the location of the top of the strut does affect camber. Using that same logic, why didn't they put one on flagship 90-96 cars that they pulled out the stops on in many other respects?
Quote »Actually the bar helps dampen the tire/road vibrations by rigidizing the body! [/quote]
That's possible and probably why the 97-01 Qs have them. I just have a hard time believing they significantly affect dynamic camber. We're both just arm-chair theorizing here, but tire temperatures would tell the real story. If it does reduce deflection enough to affect camber, you'd see it in the tire temperatures. If I had ready access to a skidpad and STB, I'd go test tire temperatures with and without the STB, but unfortunately I don't have either.
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Q45tech
- Moderator
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- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Because the 90Q handling exceeded any other 4 door 3960 pound made in that year on oem tiresI suspect that they knew that the chassis deflected - helped with the understeer. The problem is as you tighten up the front sway bar bushings [causes more understeer] ........why I use the smaller [28/29 ^4= 0.87 or 13% less stiff t & a bar] with 115% [Eibach] springs...........trying to maintain roughly equal front roll stiffness........usually unsuccessful as the car feels better with about 20% more [say 50 pound inches more than stock] roll stiffness. This maybe due to my HIGHER CAPACITY front tires [1640 vs 1521 oem].......as you usually realize about half to a third of the tire difference as a gain. Obviously lots of difference in 235/60/15 Michelins and say a 215/65/15 AVS I even though they have the same load rating.When I swap between the two the sway changes almost 1" as the Michelins have a less rigid sidewall.
Each stock Q can vary greatly as the amount of slack in the front sway bars bushings varies greatly. The sway bar may do nothing in the 1st inch of sway.......in theory 146 pounds of resistance is available with 100% coupling.........so some are 146 + 10% some are 146 + 25%, some are 146 + 50%........725 pounds of weight transfer is possible but the front tires begin to wash out at 1520/1640.....long before the 1900 [0.75G [53/46 WD] for 4300 less unsprung weight] is achieved.
Front tires are the limiting factor in what is achievable in a Q as the rears are load less by 150-200 pounds.
With Eibachs you lose 1" of shock/spring travel so 3.25 inches of roll is all you have [before the bump stops] 725/3= 242 pound per inch would be perfect......but it is impossible to get this in a linear form due to rubber bushings and the Eibach are not perfectly linear [they say they are close but we have measured a 10% variance plus manufacturers tolerance say +- 15% depending on WHICH inch of compression you analyse.
Lots of this has to do with how I like it to feel in emergency lane changes at 70-80 mph..........whether the ultimate grip is better or worse is immaterial to me ........avoiding accidents is my main concern.
With the compression washers on my bushings I can vary the bar coupling in 1/4 [90 degree] turn increments [not necessary stable as the rubber changes under load].........from full compression to just 3/4 of a turn out is a radical difference affecting the front sway by ALMOST AN INCH AT FULL LOAD.......the problem is the straight ahead impact harhness varies at the same rate.
When you rigidize the sway bar [take out the 1st inch slop] much more vibration and stress get transmitted to the shock tower and frame thus the need for the strut tower brace to help dampen [cancel the side to side movement as the chassis twists].
The 97Q has a sway bar which has longer B arms and directly mounts to the bottom of strut through on one rubber isolator so the bar is weaker than the 90-96 sway bar CAN BE.
The other problem is that the steering rack is rubber isolated and feeds the tie rods BEHIND the suspension center thus under stress the steering has a natural toe in extra component which adds to the UNDERSTEER {position of steering wheel vs actual tire position] vs the normal tire slip steer angle.
Again the bar seems to help the steering feel.
Each stock Q can vary greatly as the amount of slack in the front sway bars bushings varies greatly. The sway bar may do nothing in the 1st inch of sway.......in theory 146 pounds of resistance is available with 100% coupling.........so some are 146 + 10% some are 146 + 25%, some are 146 + 50%........725 pounds of weight transfer is possible but the front tires begin to wash out at 1520/1640.....long before the 1900 [0.75G [53/46 WD] for 4300 less unsprung weight] is achieved.
Front tires are the limiting factor in what is achievable in a Q as the rears are load less by 150-200 pounds.
With Eibachs you lose 1" of shock/spring travel so 3.25 inches of roll is all you have [before the bump stops] 725/3= 242 pound per inch would be perfect......but it is impossible to get this in a linear form due to rubber bushings and the Eibach are not perfectly linear [they say they are close but we have measured a 10% variance plus manufacturers tolerance say +- 15% depending on WHICH inch of compression you analyse.
Lots of this has to do with how I like it to feel in emergency lane changes at 70-80 mph..........whether the ultimate grip is better or worse is immaterial to me ........avoiding accidents is my main concern.
With the compression washers on my bushings I can vary the bar coupling in 1/4 [90 degree] turn increments [not necessary stable as the rubber changes under load].........from full compression to just 3/4 of a turn out is a radical difference affecting the front sway by ALMOST AN INCH AT FULL LOAD.......the problem is the straight ahead impact harhness varies at the same rate.
When you rigidize the sway bar [take out the 1st inch slop] much more vibration and stress get transmitted to the shock tower and frame thus the need for the strut tower brace to help dampen [cancel the side to side movement as the chassis twists].
The 97Q has a sway bar which has longer B arms and directly mounts to the bottom of strut through on one rubber isolator so the bar is weaker than the 90-96 sway bar CAN BE.
The other problem is that the steering rack is rubber isolated and feeds the tie rods BEHIND the suspension center thus under stress the steering has a natural toe in extra component which adds to the UNDERSTEER {position of steering wheel vs actual tire position] vs the normal tire slip steer angle.
Again the bar seems to help the steering feel.
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greg_atlanta
- Posts: 1111
- Joined: Tue Jul 23, 2002 4:37 pm
- Car: 2008 G35 Journey Sedan, silver/black (no sunroof), 1992 Q45 (in a past life)
stillen bar installation questions
My Stillen bar arrived yesterday! They sent out a 2003 catalog with the order and the bar is no longer in their catalog,so if you want one ORDER YOURS TODAY!One question,does anyone know the correct torque specs for the strut nuts and bar nuts?
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Jeff Williams
- Posts: 3394
- Joined: Fri Aug 02, 2002 4:17 am
- Car: 1994 Infiniti Q45t
2000 Infiniti I30t
2004 Infiniti M45
71, 72, 73, 82 & 2000 Corvettes - Contact:
I agree with Greg in Atlanta. My '94 Q feels like it lost about 1000#, since I put the strut bar in place.
Being a cheap person by nature, I bout a BOMZ racing strut bar for my wife's 2000 I30 from eBay for $17.00
It, amazingly, is the right length for my '94 Q45. All I had to do. was drill a couple of holes in the rings, and re-drill the mounting location for the bar (shorten the tabs on the rings). This took me about 1 hour, and saved me $110.00 over the Stillen part.
I have put about 10,000 miles on the car, since my retrofit, and now my front right strut is now squeaking. 145,000 miles on the ODO, it might be time to replace them all.
Jeff
Being a cheap person by nature, I bout a BOMZ racing strut bar for my wife's 2000 I30 from eBay for $17.00
It, amazingly, is the right length for my '94 Q45. All I had to do. was drill a couple of holes in the rings, and re-drill the mounting location for the bar (shorten the tabs on the rings). This took me about 1 hour, and saved me $110.00 over the Stillen part.
I have put about 10,000 miles on the car, since my retrofit, and now my front right strut is now squeaking. 145,000 miles on the ODO, it might be time to replace them all.
Jeff
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Movingviolation240
- Posts: 1681
- Joined: Thu Apr 25, 2002 2:26 pm
- Car: '95 Nissan 240SX 400hp SR20DET -SOLD
'93 Lexus SC300 w/ SP66 turbo kit
I'm jumping in on this one a bit late, and I have strut suspension so I'm not sure how much help this will be to everybody, but I noticed a definate improvement when I stuck one on my '93 and later my '95 240sx. Understeer is eveil as we all know, and the STB helped get rid of a little bit of that. Anytime I can get the thing to be more neutral for under $20 I think it's a good deal.
the real difference is when you stick one in the back of a hatchback 240. Even though it's a shock rear settup there is a marked improvement (and most 240 guys will attest to that) Heck in a hatch 240 you can HEAR the difference since the hatch dosn't rattle around as much.
PaulOrlando, FL
the real difference is when you stick one in the back of a hatchback 240. Even though it's a shock rear settup there is a marked improvement (and most 240 guys will attest to that) Heck in a hatch 240 you can HEAR the difference since the hatch dosn't rattle around as much.
PaulOrlando, FL
