My car is a 1991 q45a with 110k miles. It was bought used in NH with 62k miles on it. It was and still is a NE car.
The guides were done and the transmission was replaced before I bought the car. While I was looking for a Q, I test drove a 1991 Q45T, standard and active. The active felt the most powerful. So that is the one I bought.
My question is, from a performance point of view, should I switch to a conventional suspension?
I do know the 1991 Q45a was the only Q that was hit with a gas guzzler tax when they sold as new cars. I believe someone said the a/s adds about 400lbs to the car. I don't really care about the cost of maintaining the a/s nor the cost of replacing the conventional shocks every 40k miles, my concern is performance. Will my car perform so much better in acceleration and stopping that it is worth doing the switch?
Active Suspension, should it stay or should it go?
That's true Fred. If I do the switch, I'll have the entire system pulled out.palmerwmd wrote:Also when converting you keep much of the system weight in the car still.
I don't plan on taking the car to the track, but I do want to sqeeze the most performance out of her as I can. From being a member of this forum, I have learned that heat and weight will rob your car of performance.
I do recall fxjackso saying the performance difference in his active Q and his standard Q, both with JWT ecu and tcu, was significant.
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maxnix
- Posts: 22627
- Joined: Mon Jul 22, 2002 8:11 pm
- Car: 1995 Infiniti Q45
1995 Infiniti Q45t
2000 Infiniti Q45
Optimizing Performance
Quote »I do want to sqeeze the most performance out of her as I can[/quote] Then I would say keep it stock. If you don't like the active, then get a standard or t. It makes little sense to convert just because one bought the wrong model, and now envisions cost savings by converting it to the specifications of a different model.
As pointed out by Q45tech in the post following this one:Quote »A total retrofit would require new ecu, new power steering pump, pullies and belts plus another 5 - 6 hours of work over and above the simple pump loopback and 4 shock/spring change out.......to get every pound of dead weight and meet non active performance.
For most a $1300 change is enough vs a total $2,800 R&R.[/quote]
Keep it stock, or get the model you want.
As pointed out by Q45tech in the post following this one:Quote »A total retrofit would require new ecu, new power steering pump, pullies and belts plus another 5 - 6 hours of work over and above the simple pump loopback and 4 shock/spring change out.......to get every pound of dead weight and meet non active performance.
For most a $1300 change is enough vs a total $2,800 R&R.[/quote]
Keep it stock, or get the model you want.
Hmmm...I've been totally satisfied with my conversion. Believe me, after removing all the Active Suspension components, the car is definitely faster on its feet.
The ActSus system weighs about a good 250 lbs. I'd say, that's just the main components not including the fluid and lines. I have a 22mm custom rear sway bar, energy suspension bushings throughout and the tokicos. Body roll is significant reduced and I can honestly say, my Q handles better than any other Q I've ever driven, period and I'm still rollin on H-rated 215's.
The ActSus system weighs about a good 250 lbs. I'd say, that's just the main components not including the fluid and lines. I have a 22mm custom rear sway bar, energy suspension bushings throughout and the tokicos. Body roll is significant reduced and I can honestly say, my Q handles better than any other Q I've ever driven, period and I'm still rollin on H-rated 215's.
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texasoil
- Posts: 875
- Joined: Mon Sep 02, 2002 3:18 pm
- Car: '92 Infiniti Q45A
'94 Infiniti Q45A
'94 Mercedes-Benz SL600
active or not? which way to go/stay
Max performance on the track is different things to different folks. What kind of track? Straight line dragging dump all the weight possible.
Curves and bumps it's real hard to beat a working active Q. Those of us who have driven one in good shape love them. The secret is getting the accumulators recharged. No dive on braking,no squat on accelerating, flat cornering until over 0.5g, then system allow a little for feedback. No compromises on chassis compliance like there is with non-active stuff.
Only hitch is it doesn't handle well the negative G's(like getting all wheels in the air going over a sharp hill) --gets confused - car body has negative G force, wheels are showing lots of extension--not a normal situation the control algorithims are designed to master. Tends to hit hard--no damage, just not well mannered
Curves and bumps it's real hard to beat a working active Q. Those of us who have driven one in good shape love them. The secret is getting the accumulators recharged. No dive on braking,no squat on accelerating, flat cornering until over 0.5g, then system allow a little for feedback. No compromises on chassis compliance like there is with non-active stuff.
Only hitch is it doesn't handle well the negative G's(like getting all wheels in the air going over a sharp hill) --gets confused - car body has negative G force, wheels are showing lots of extension--not a normal situation the control algorithims are designed to master. Tends to hit hard--no damage, just not well mannered
Everyone that has weighed in on this topic has presented very influential opinions. I kinda figured it was going to be a matter of preference. The best solution would be to get a standard 1990 Q and restore the 1991 active back to factory specs. However, that's not likely to happen.
Decisions. Decisions.
Anyway thanks for the great advice.
Decisions. Decisions.
Anyway thanks for the great advice.
I just recharged mine.. I like the way it feels. I didnt get this car to race around.. so the difference of 200 lbs, wont be THAT significant..... after drving the active for a while, its not MINDBLOWING amazing, but its a very comfortable ride. on the highway, or long swooping curves, you are cruising around at such a high rate of speed without any leaning, that it is really amazing that such a heavy car, stays so well planted.
Im glad I had mine recharged ( but then again its only been a few weeks) Ill let everyong know how the recharge hold up.
Im glad I had mine recharged ( but then again its only been a few weeks) Ill let everyong know how the recharge hold up.
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texasoil
- Posts: 875
- Joined: Mon Sep 02, 2002 3:18 pm
- Car: '92 Infiniti Q45A
'94 Infiniti Q45A
'94 Mercedes-Benz SL600
Active system weight penalty
I have to admit I have not collected all the active system parts and wieghed them, but I do have at least one of everything. For the life of me, I cannot get anywhere near the '250#' that is mentioned as 'the weight penalty'. That 250# must also include the rear sway bar and mounts and the heavier front sway bar..
The hydraulic accumulators (steel) wiegh about 45# total. The reservior full of oil weighs another 20#. The 3 solenoid valve assemblies and mounts weigh another 30# combined. The extra pump weight is probably another 10#, and the oil cooler and fan weigh another 15# all in. Sensors and wiring maybe another 10 # total. That's about 130 # so far. (the struts may weigh a couple of pounds more each say 10# for 4 , thats a total of 140. Plumbing can't weigh more than 30# in all,-for a grand total of 170#+/-
If one is racing take everything out, including all the sound insulation,seats, carpets, A/C system,power locks and windows--strip the beast. However, for 99.9% of the people, carrying around the equivalent weight 'penalty' of a passenger is not ever noticeable.
The hydraulic accumulators (steel) wiegh about 45# total. The reservior full of oil weighs another 20#. The 3 solenoid valve assemblies and mounts weigh another 30# combined. The extra pump weight is probably another 10#, and the oil cooler and fan weigh another 15# all in. Sensors and wiring maybe another 10 # total. That's about 130 # so far. (the struts may weigh a couple of pounds more each say 10# for 4 , thats a total of 140. Plumbing can't weigh more than 30# in all,-for a grand total of 170#+/-
If one is racing take everything out, including all the sound insulation,seats, carpets, A/C system,power locks and windows--strip the beast. However, for 99.9% of the people, carrying around the equivalent weight 'penalty' of a passenger is not ever noticeable.