Counter acting roll out with gear ratio changes.
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Joined: Dec 2006
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From: Gold Coast, Qld, Australia
Counter acting roll out with gear ratio changes.
Yes I am the uber n00b So Hi to all, and thanks in advance for going a little easy on me. I have searched and read for the last 45min, but nothing directly relates to my Q. I have put it here as it is a tec Q. If it should be moved, pls let me know and I will post it elsewhere.
Car in question is my Australian domestic Market 1998 Prelude ATTS (Type SH for the US) Some minor changes, but essentially the same car. This Q relates to all (non I-Vtec) Hondas though.
I have identified my tranny form the variations here
https://honda-tech.com/zerothread?id=758902
Am well aware of the theory relating to gearing/tire changes on a cars final roll out. And use this http://www.locost7.info/gearcalc.php awesome program to mess with the “theory” of what I want to do. A quick and worthwhile download if you don’t have it.
Scenario is.. I would like to move up from the nice, but rather roller skate like 16” (205/50/16) wheels my car was endowed with from the factory to a far more pimp 18 inch wheel.
Things I have considered….
1. YES!!! I could get a 17” x 7.5” rim and a 205/40/17 tire and keep the same rollout and essentially have a cost/ride effective solution BUT… My car has the full Mugen body kit and those of you familiar with this kit will agree that the over hang (distance from front wheel arch to end of bar) is quite long, so long in fact, it makes any driving on any incline a nail biting experience, particularly car park ramps… even though the car is not stupidly low, it scrapes because of the angle.
2. The kit alone puts my vehicle almost on the on the exact legal ride height limit of 100mm for my area and I do intend to lower / stiffen the suspension with adjustable coil overs as my next upgrade after wheels. Hence a larger rolling diameter wheel will be beneficial to me as part of my overall plan for my car…. A larger wheel will allow me some room to lower the car and essentially fill out the void in the guards for that sexy look, while stiffening up the ride for better handling.
3. A solution of a 30 series tire is impractical based on cost / ride quality. I need a 35 or 40 series tire.
4. I want to keep a 205 width in a tire, as a 215 will in fact have NEGATIVE handling consequences on my vehicle, but there is a noticeable lack the lack of manufactures who supply a 205/35or40/18 at a reasonable cost. The range of wheels for a18x7.5” rim vs. 18x8” is also a lot more limiting. So, I am willing to go to a 215 and 18x8 if necessary.
5. Most importantly. Honda are very specific about the gearing and rollout for its’ vehicles because of the crucial V-tec cut in point. I put 18’s on my last car (Teg GSR) and the difference in performance was painfully noticeable. A VETC controller is not a valid option in this case, that would be a work around, not a fix.
6. 5th gear, as is reasonably common place in the ‘lude has had the proverbial sausage, so the box is due to come out for some syncro work shortly anyway.
Given the above constraints, I have the following Q’s.
1. From a hand's on perspective, could an adjustment of the final drive compensate within reason (given torque / engine power band characteristics, H22A) for a larger rolling diameter wheel, allowing the shifts to remain on the creamy vtec cam? Or would every gear need changing?
b. If the changing of the final drive alone is a reasonable solution, from a practical point of view, how hard is it to change given the box will be out and open anyway? Is it many hours labor?… would finding a suitable cog be a nightmare and possibly require fabrication?
2. Does anyone know the weight of a 16” type SH rim. Yes I can weigh it and I’m being lazy, but if you happen to know it would be a huge help.
3. How noticeable is the effect of increasing the un-sprung weight of the vehicle in terms of acceleration… will it void the effect of my lightened flywheel or worse have a synergy type effect with the flywheel and put high levels of stress on the engine/drive train?
4. Any recommendations for quality / light weight 18 x 7.5 (preferably) 18 x 8.0 (acceptable) with a 5 x 114.3 stud pattern and + 40 offset?
Thanks very much in advance
n1nj4
Car in question is my Australian domestic Market 1998 Prelude ATTS (Type SH for the US) Some minor changes, but essentially the same car. This Q relates to all (non I-Vtec) Hondas though.
I have identified my tranny form the variations here
https://honda-tech.com/zerothread?id=758902
Am well aware of the theory relating to gearing/tire changes on a cars final roll out. And use this http://www.locost7.info/gearcalc.php awesome program to mess with the “theory” of what I want to do. A quick and worthwhile download if you don’t have it.
Scenario is.. I would like to move up from the nice, but rather roller skate like 16” (205/50/16) wheels my car was endowed with from the factory to a far more pimp 18 inch wheel.
Things I have considered….
1. YES!!! I could get a 17” x 7.5” rim and a 205/40/17 tire and keep the same rollout and essentially have a cost/ride effective solution BUT… My car has the full Mugen body kit and those of you familiar with this kit will agree that the over hang (distance from front wheel arch to end of bar) is quite long, so long in fact, it makes any driving on any incline a nail biting experience, particularly car park ramps… even though the car is not stupidly low, it scrapes because of the angle.
2. The kit alone puts my vehicle almost on the on the exact legal ride height limit of 100mm for my area and I do intend to lower / stiffen the suspension with adjustable coil overs as my next upgrade after wheels. Hence a larger rolling diameter wheel will be beneficial to me as part of my overall plan for my car…. A larger wheel will allow me some room to lower the car and essentially fill out the void in the guards for that sexy look, while stiffening up the ride for better handling.
3. A solution of a 30 series tire is impractical based on cost / ride quality. I need a 35 or 40 series tire.
4. I want to keep a 205 width in a tire, as a 215 will in fact have NEGATIVE handling consequences on my vehicle, but there is a noticeable lack the lack of manufactures who supply a 205/35or40/18 at a reasonable cost. The range of wheels for a18x7.5” rim vs. 18x8” is also a lot more limiting. So, I am willing to go to a 215 and 18x8 if necessary.
5. Most importantly. Honda are very specific about the gearing and rollout for its’ vehicles because of the crucial V-tec cut in point. I put 18’s on my last car (Teg GSR) and the difference in performance was painfully noticeable. A VETC controller is not a valid option in this case, that would be a work around, not a fix.
6. 5th gear, as is reasonably common place in the ‘lude has had the proverbial sausage, so the box is due to come out for some syncro work shortly anyway.
Given the above constraints, I have the following Q’s.
1. From a hand's on perspective, could an adjustment of the final drive compensate within reason (given torque / engine power band characteristics, H22A) for a larger rolling diameter wheel, allowing the shifts to remain on the creamy vtec cam? Or would every gear need changing?
b. If the changing of the final drive alone is a reasonable solution, from a practical point of view, how hard is it to change given the box will be out and open anyway? Is it many hours labor?… would finding a suitable cog be a nightmare and possibly require fabrication?
2. Does anyone know the weight of a 16” type SH rim. Yes I can weigh it and I’m being lazy, but if you happen to know it would be a huge help.
3. How noticeable is the effect of increasing the un-sprung weight of the vehicle in terms of acceleration… will it void the effect of my lightened flywheel or worse have a synergy type effect with the flywheel and put high levels of stress on the engine/drive train?
4. Any recommendations for quality / light weight 18 x 7.5 (preferably) 18 x 8.0 (acceptable) with a 5 x 114.3 stud pattern and + 40 offset?
Thanks very much in advance
n1nj4
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