New Gears.
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New Gears.
i recently had some engine work done to my g35 which is the 5 speed auto, i had installed tomei 264 cams and new valve springs and retainers, i also got the Osiris tune and my redline is now at 8000 rpm's. the problem i have come across is from a roll my car is fast but from a dead stop i am slow. i have heard some ideas like putting 4.10 gears but i honestly have no clue about gears, i was wondering if anyone had any suggestions. Thanks.
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Part of that problem is your car is relatively heavy, and the engine is built to deliver its power in the higher RPM range.
However, there is one thing you might want to check on, being that its an auto...the stall of the torque converter. In a newer vehicle like yours the stall is likely controlled by the ECU, unlike older ones that were mechanically controlled. Chances are its set for a smooth, soft take off, and a fairly high RPM for lock-up. To get a good idea of what your lock-up RPM is put your car in drive, hold one foot on the break, and while watching the tach slowly give it gas. The RPM at which it starts to overpower the brakes is approx your stall RPM.
You have to choices if you want to change this RPM. The decision is based on how you want to drive.
1) Lower stall RPM...this will give you a quicker snap off the line, as the torque converter will lock up earlier, and youwill get full power to the wheels quicker. This is the better choice for daily driven mild street cars.
2) Higher stall RPM. This will allow you to pull the engine to higher RPM (closer to your power band) and allow a much more aggressive launch. This is the better choice if you are going to race the car from a dig a lot. However, it MIGHT lead to more lethargic off the line acceleration during normal driving.
Talk to the people who tuned your ECU if you are interested in this.
As far as your question on gears...changing to a different ratio certainly can help your low end acceleration. However there are trade-offs. Your RPM at cruising speeds will be higher, and your top speed will likely be lower.
However, there is one thing you might want to check on, being that its an auto...the stall of the torque converter. In a newer vehicle like yours the stall is likely controlled by the ECU, unlike older ones that were mechanically controlled. Chances are its set for a smooth, soft take off, and a fairly high RPM for lock-up. To get a good idea of what your lock-up RPM is put your car in drive, hold one foot on the break, and while watching the tach slowly give it gas. The RPM at which it starts to overpower the brakes is approx your stall RPM.
You have to choices if you want to change this RPM. The decision is based on how you want to drive.
1) Lower stall RPM...this will give you a quicker snap off the line, as the torque converter will lock up earlier, and youwill get full power to the wheels quicker. This is the better choice for daily driven mild street cars.
2) Higher stall RPM. This will allow you to pull the engine to higher RPM (closer to your power band) and allow a much more aggressive launch. This is the better choice if you are going to race the car from a dig a lot. However, it MIGHT lead to more lethargic off the line acceleration during normal driving.
Talk to the people who tuned your ECU if you are interested in this.
As far as your question on gears...changing to a different ratio certainly can help your low end acceleration. However there are trade-offs. Your RPM at cruising speeds will be higher, and your top speed will likely be lower.
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Part of that problem is your car is relatively heavy, and the engine is built to deliver its power in the higher RPM range.
However, there is one thing you might want to check on, being that its an auto...the stall of the torque converter. In a newer vehicle like yours the stall is likely controlled by the ECU, unlike older ones that were mechanically controlled. Chances are its set for a smooth, soft take off, and a fairly high RPM for lock-up. To get a good idea of what your lock-up RPM is put your car in drive, hold one foot on the break, and while watching the tach slowly give it gas. The RPM at which it starts to overpower the brakes is approx your stall RPM.
You have to choices if you want to change this RPM. The decision is based on how you want to drive.
1) Lower stall RPM...this will give you a quicker snap off the line, as the torque converter will lock up earlier, and youwill get full power to the wheels quicker. This is the better choice for daily driven mild street cars.
2) Higher stall RPM. This will allow you to pull the engine to higher RPM (closer to your power band) and allow a much more aggressive launch. This is the better choice if you are going to race the car from a dig a lot. However, it MIGHT lead to more lethargic off the line acceleration during normal driving.
Talk to the people who tuned your ECU if you are interested in this.
As far as your question on gears...changing to a different ratio certainly can help your low end acceleration. However there are trade-offs. Your RPM at cruising speeds will be higher, and your top speed will likely be lower.
However, there is one thing you might want to check on, being that its an auto...the stall of the torque converter. In a newer vehicle like yours the stall is likely controlled by the ECU, unlike older ones that were mechanically controlled. Chances are its set for a smooth, soft take off, and a fairly high RPM for lock-up. To get a good idea of what your lock-up RPM is put your car in drive, hold one foot on the break, and while watching the tach slowly give it gas. The RPM at which it starts to overpower the brakes is approx your stall RPM.
You have to choices if you want to change this RPM. The decision is based on how you want to drive.
1) Lower stall RPM...this will give you a quicker snap off the line, as the torque converter will lock up earlier, and youwill get full power to the wheels quicker. This is the better choice for daily driven mild street cars.
2) Higher stall RPM. This will allow you to pull the engine to higher RPM (closer to your power band) and allow a much more aggressive launch. This is the better choice if you are going to race the car from a dig a lot. However, it MIGHT lead to more lethargic off the line acceleration during normal driving.
Talk to the people who tuned your ECU if you are interested in this.
As far as your question on gears...changing to a different ratio certainly can help your low end acceleration. However there are trade-offs. Your RPM at cruising speeds will be higher, and your top speed will likely be lower.
^ +1 what he said
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id ask some g/z guys to be sure. But if the r200 s chassis 4.08 would work you'd save a shitload.
Sorta like how the nismo 4.63 r&p is 500$ but you can use an xterra r&p
Sorta like how the nismo 4.63 r&p is 500$ but you can use an xterra r&p
