Can anyone help me with part numbers (or comparable interchange #'s) for poly bushings for the Q front and rear sway bars?
I'm gonna be spending some time in the garage here pretty soon, so I want to have all my parts ready to rock!
Thanks much!
Suspension Techniques bushings for Q
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maxnix
- Posts: 22627
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- Car: 1995 Infiniti Q45
1995 Infiniti Q45t
2000 Infiniti Q45
Here's the rear a model urethane bushing
Energy Suspension #95124 is a 20mm bushing with the smaller of their two bracket sizes and is a perfect fit. It does not come in greasable setup, but you can get the bushings with graphite in them.
Courtesy of fxjackso at http://www.nissaninfiniticlub....thane
Might read Q45tech's comments there also. For the front, you'll have to do your own search, like any other newbie.
Courtesy of fxjackso at http://www.nissaninfiniticlub....thane
Might read Q45tech's comments there also. For the front, you'll have to do your own search, like any other newbie.
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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
The stock front bar is very very stiff [relative to what would be normal]. The bar is 29mm in diameter BUT has very short [6"] arms compared to newer models.......because the bar is coupled to the traverse arm at the midpoint [divide by 4].
In order to make this work there is intentional slop in the end link bushings [by limiting how tight you can crush the 2 bushings].
If you think about it the front is overly stiff compared to the 146 pound inch springs and needs the delayed action [the bar does not couple in the first 1" of body roll.
Stiffening the front is the last thing you want to do as the understeer will just increase.Removing the slack/slop will add over 150-160 pounds of roll stiffness from the first inch thru the 3.5 inch. It will reduce the body roll by 1" but the bump harshness will be severe to say the least.The front bar is in rubber [to the frame] because there is a slight angle which makes urethane difficult!
Just install 2 metal washers between the bottom rubber retainer and the nut on each side .............you can then adjust the attack point better by squishing the rubber bushing slightly............a quarter of a turn on the nut is quite feeable as the bar couples.
Ideally you want to balance the bar with shims [washers] so that when you are stitting in the seat both sides [arms] are the same since just 200 pounds will move the drivers side down by 66/146=0.4" so divide by 4 the bar will be 1/10" out of level.
In order to make this work there is intentional slop in the end link bushings [by limiting how tight you can crush the 2 bushings].
If you think about it the front is overly stiff compared to the 146 pound inch springs and needs the delayed action [the bar does not couple in the first 1" of body roll.
Stiffening the front is the last thing you want to do as the understeer will just increase.Removing the slack/slop will add over 150-160 pounds of roll stiffness from the first inch thru the 3.5 inch. It will reduce the body roll by 1" but the bump harshness will be severe to say the least.The front bar is in rubber [to the frame] because there is a slight angle which makes urethane difficult!
Just install 2 metal washers between the bottom rubber retainer and the nut on each side .............you can then adjust the attack point better by squishing the rubber bushing slightly............a quarter of a turn on the nut is quite feeable as the bar couples.
Ideally you want to balance the bar with shims [washers] so that when you are stitting in the seat both sides [arms] are the same since just 200 pounds will move the drivers side down by 66/146=0.4" so divide by 4 the bar will be 1/10" out of level.
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Q45tech
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1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
The Eibachs are balanced roughly 15% stiffer front and rear until the last inch on the rear which is stiffer [progressive rear - linear front].
146x 1.15...........= 168>168>16829mm bar w/rub.= 060>130>160------------------------------------------Front Total.........= 228>298>328 cumlative @3"= 854#
Rear guestimate stiffness:123x1.15-1.3-1.62=142>160>20020 mm bar w/rub=025>040>040-----------------------------------------Total...................=167>200>240 cumlative@3" = 607#
Total roll stiffness at 3" 854 + 607= 1461Front roll couple ratio 854/1461=~~~58% vs 54% front weight therefore still understeers.
4300 minus unsprung weight [500?]=3800/2=1900 1461/1900=0.769G possible at 3" body roll.
If the front bar was coupled stiffer that would add 130 pounds of front roll resistance to the 854 +130=984
984 vs 607 total rear = 1591 984/1591=61.85% front roll couple ratio vs 58% with losely coupled front bar.
The above is an approximation so say within 3-5% of being absolutely correct.
What happened with the Stillen Big rear bar was they found it to cause over steer with Eibachs so the just stiffened the front bar to bring back into control.
Hope you can see how critical the coupling of the front bar is with old worn out sloppy bushings the front bar might not engage fully till 2" of body roll [or at 1"] so you could have under: 54%, or 56%, or 58%, or 60% or 62%................all in the range of 1/4" of total slack........1/8" on each side of where the bar mounts to the traverse arm.
A funky design that was not fixed till 97Q.
Every Q handles differently because of this variable plus of course tires and alignment
146x 1.15...........= 168>168>16829mm bar w/rub.= 060>130>160------------------------------------------Front Total.........= 228>298>328 cumlative @3"= 854#
Rear guestimate stiffness:123x1.15-1.3-1.62=142>160>20020 mm bar w/rub=025>040>040-----------------------------------------Total...................=167>200>240 cumlative@3" = 607#
Total roll stiffness at 3" 854 + 607= 1461Front roll couple ratio 854/1461=~~~58% vs 54% front weight therefore still understeers.
4300 minus unsprung weight [500?]=3800/2=1900 1461/1900=0.769G possible at 3" body roll.
If the front bar was coupled stiffer that would add 130 pounds of front roll resistance to the 854 +130=984
984 vs 607 total rear = 1591 984/1591=61.85% front roll couple ratio vs 58% with losely coupled front bar.
The above is an approximation so say within 3-5% of being absolutely correct.
What happened with the Stillen Big rear bar was they found it to cause over steer with Eibachs so the just stiffened the front bar to bring back into control.
Hope you can see how critical the coupling of the front bar is with old worn out sloppy bushings the front bar might not engage fully till 2" of body roll [or at 1"] so you could have under: 54%, or 56%, or 58%, or 60% or 62%................all in the range of 1/4" of total slack........1/8" on each side of where the bar mounts to the traverse arm.
A funky design that was not fixed till 97Q.
Every Q handles differently because of this variable plus of course tires and alignment
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Q45tech
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1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Note that with the stock springs and 29 mm front bar and no rear bar the ratios are quite different:Front stock788 vs mod854@3"Rear stock369 vs mod607@3"
The rear probably won't roll the entire 3" in modified form.369/607=.6 x 3= 1.8" more or less at the same G force as it did with stock springs and no bar but the forces will be partially shifted to the front. So the front will probably roll the same even with the 15% stiffer springs.
Kind of a iterated process, stiffen the back the front rolls more.Stiffen the front bar to reduce the front roll and the rear rolls more.The other problem is the isolated rear subframe which will move in response to load [some].The rear center of gravity and the instant roll center are very high compared to the front so even though the rear has less weight to shift the percentage is higher..........what happens is the tire load equalizes from the 54% front static to at least 50/50 in a 0.75 G turn..........in fact some testing indicates that with Eibachs and 20 mm rear bar the rear tires may be subjected to a greater load than the front.................really depends on the exact coupling of the front bar........and whether you are accelerating or decelerating in out of the corner.
On mine I have reduced the front bar diameter from 29 to 28 mm [the active and T car front bar]........a 13% reduction in stiffness so that the 15% stiffer springs and the softer bar cancel each other out!This may be counterintuitive but it acts like I have stiffened the rear bar more...........anyway this makes my front stiffness the same as stock in a 3" roll but stiffer in a 1" roll where the springs are the main factor.
Eibachs choice of rear progressives is less than ideal as the sudden increase in stiffness makes for a less than stable situation in severe transistions [auto cross].........doesn't much matter since the shocks [even blues] are not stiff enough in rebound.
Ideally something like a 22.5mm rear bar would control rear body roll better and keep the springs out of the really stiff last inch of compresssion.
The 90-96 300zxtt has a rear 21.5mm bar with an almost identical rear suspension [track is 1" narrower] and the weight is about 200 pounds less.
The rear probably won't roll the entire 3" in modified form.369/607=.6 x 3= 1.8" more or less at the same G force as it did with stock springs and no bar but the forces will be partially shifted to the front. So the front will probably roll the same even with the 15% stiffer springs.
Kind of a iterated process, stiffen the back the front rolls more.Stiffen the front bar to reduce the front roll and the rear rolls more.The other problem is the isolated rear subframe which will move in response to load [some].The rear center of gravity and the instant roll center are very high compared to the front so even though the rear has less weight to shift the percentage is higher..........what happens is the tire load equalizes from the 54% front static to at least 50/50 in a 0.75 G turn..........in fact some testing indicates that with Eibachs and 20 mm rear bar the rear tires may be subjected to a greater load than the front.................really depends on the exact coupling of the front bar........and whether you are accelerating or decelerating in out of the corner.
On mine I have reduced the front bar diameter from 29 to 28 mm [the active and T car front bar]........a 13% reduction in stiffness so that the 15% stiffer springs and the softer bar cancel each other out!This may be counterintuitive but it acts like I have stiffened the rear bar more...........anyway this makes my front stiffness the same as stock in a 3" roll but stiffer in a 1" roll where the springs are the main factor.
Eibachs choice of rear progressives is less than ideal as the sudden increase in stiffness makes for a less than stable situation in severe transistions [auto cross].........doesn't much matter since the shocks [even blues] are not stiff enough in rebound.
Ideally something like a 22.5mm rear bar would control rear body roll better and keep the springs out of the really stiff last inch of compresssion.
The 90-96 300zxtt has a rear 21.5mm bar with an almost identical rear suspension [track is 1" narrower] and the weight is about 200 pounds less.
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Jeff Williams
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I was kind ahoping for a more detailed response.....
Just kidding!
Q45tech, you are amazing! Thanks for the info. in a precise, understandable format.
I am convinced I need the Tokiko Blues, and want the active rear sway bar. I already have 17" wheels, and high performance tires. Do you see anything I should do, in addition, to hel provide a balanced handling upgrade?
I do not intend to put Eibachs on the car, but I might try to shave a 1/4 turn or so, off the original springs, when I install the Tokikos, to lower the CG. It would not take much to talk me out of doing this, if you have an opinion.
George Akin has a set of Tokiko blues, from his '91 Q. I knoq the rears are the same, but the fronts have a different part number for my '94. Is this a significant difference?
Just kidding!Q45tech, you are amazing! Thanks for the info. in a precise, understandable format.
I am convinced I need the Tokiko Blues, and want the active rear sway bar. I already have 17" wheels, and high performance tires. Do you see anything I should do, in addition, to hel provide a balanced handling upgrade?
I do not intend to put Eibachs on the car, but I might try to shave a 1/4 turn or so, off the original springs, when I install the Tokikos, to lower the CG. It would not take much to talk me out of doing this, if you have an opinion.
George Akin has a set of Tokiko blues, from his '91 Q. I knoq the rears are the same, but the fronts have a different part number for my '94. Is this a significant difference?
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Q45tech
- Moderator
- Posts: 14296
- Joined: Tue Apr 30, 2002 3:19 am
- 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
The springs are almost a waste of time since even 1" lowering changes the C of G only 0.9" and 23/61 or 22.1/61 is 0.377> 0.36 coupling ratio ..........a whopping 0.017 difference..........changes the transfer load by 17-20 pounds.....against the 400 shifted.
The increase in camber is the down side and an extra 0.8 degrees NEGATIVE is significant on worn cars which may already be above the ideal - 0.83!
Tire rack test show a 1-1.5% improvement [better G numbers] in handling via springs alone........looks right to me.
The springs do help in braking by resisting dive by 132 pounds so the front drops 0.35" - 0.45" less in a maximal stop. Allowing less weirness in toe in and camber which increases dramatically as the front dives.
While on the alignment rack use a chain hoist to pull the front body down you will see the camber go from -1.0 to -2.5 degrees....luckily the 15" tires are forgiving [tall sidewalls] and the braking only takes 2-3 seconds.
The active car braked as well or better than the non active because the camber didn't change as much even though the extra weight on the front.
The absolute best thing you can do is find front tires which exceed the 1521 pound load rating ....1600 >1700 would be better...........since the slip angle is a function of real load/max load. Finding a 100 pound higher load rated tire will net about 2.5-3% improvement in the angle vs weight applied......assuming the same compound.
Notice that the big MB and BMW use 98Z or 101Z on the front.....this is how they achieve even with the relatively had Michelin MXV4 plus............unfortunately the trend is away fron super strong forgiving heavy duty tires to wider lower.
People complain about body roll but don't realize you would have to double the spring stiffness to halve the roll........even 15% increase is pretty severe on a lux car as the springs are optimized to resist the pitching from road seams at the 55-65 mph range.......but if you always drive 75-80 mph they work ok.
The increase in camber is the down side and an extra 0.8 degrees NEGATIVE is significant on worn cars which may already be above the ideal - 0.83!
Tire rack test show a 1-1.5% improvement [better G numbers] in handling via springs alone........looks right to me.
The springs do help in braking by resisting dive by 132 pounds so the front drops 0.35" - 0.45" less in a maximal stop. Allowing less weirness in toe in and camber which increases dramatically as the front dives.
While on the alignment rack use a chain hoist to pull the front body down you will see the camber go from -1.0 to -2.5 degrees....luckily the 15" tires are forgiving [tall sidewalls] and the braking only takes 2-3 seconds.
The active car braked as well or better than the non active because the camber didn't change as much even though the extra weight on the front.
The absolute best thing you can do is find front tires which exceed the 1521 pound load rating ....1600 >1700 would be better...........since the slip angle is a function of real load/max load. Finding a 100 pound higher load rated tire will net about 2.5-3% improvement in the angle vs weight applied......assuming the same compound.
Notice that the big MB and BMW use 98Z or 101Z on the front.....this is how they achieve even with the relatively had Michelin MXV4 plus............unfortunately the trend is away fron super strong forgiving heavy duty tires to wider lower.
People complain about body roll but don't realize you would have to double the spring stiffness to halve the roll........even 15% increase is pretty severe on a lux car as the springs are optimized to resist the pitching from road seams at the 55-65 mph range.......but if you always drive 75-80 mph they work ok.