dyno results
allied is right. the more mass you push to the outside of the rim overall is gonna affect the amount of power is needed to turn it. if you have an overall smaller 17 but you have a lot more rubber and is wider than the 16's, the increase in mass is gonna require more power.
theres a science experiment in skool where you roll a rim and a solid wheel of the same mass down a ramp and the solid wheel always wins. or something like that.
theres a science experiment in skool where you roll a rim and a solid wheel of the same mass down a ramp and the solid wheel always wins. or something like that.
Before I got my RA I had an embarrassing ES. I jumped from the stock 14's to 17's and the car was a slug. Same overall tire diameter but twice the weight. I put my stock wheels back on and it was a whole different car. Quicker (not quick), more responsive, and turned so much easier. Heavier wheels definitely make a difference. Our stock wheels and tires weigh something like 42 - 45 pounds each. If that helps anything.
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From: Ponce P.R.
I wonder whats the deal with our third gear. I was so awesome in Mirages and Lancer OZ. But as of now its the only gear I wish I could skip.
As for the topic, blame it on the dyno Ive gone to diferent dynos in my Mirage and not even the same dynos give the same results. Im familiar with Mitsu engines are not at all consistent, but, 30 hp jumps and losses are not the case.
With the Mirage for Example I run 136 hp and 127 tq in a Roller Dyno(I dont know jack about dyno types) in another it ran 106 hp and 120tq ...??
In the newest one I ran 140 hp and 136 tq, by then I lost all sort of reliability in dynos
As for the topic, blame it on the dyno Ive gone to diferent dynos in my Mirage and not even the same dynos give the same results. Im familiar with Mitsu engines are not at all consistent, but, 30 hp jumps and losses are not the case.
With the Mirage for Example I run 136 hp and 127 tq in a Roller Dyno(I dont know jack about dyno types) in another it ran 106 hp and 120tq ...??
In the newest one I ran 140 hp and 136 tq, by then I lost all sort of reliability in dynos
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From: Anderson, SC
Originally Posted by rhyzin
allied is right. the more mass you push to the outside of the rim overall is gonna affect the amount of power is needed to turn it. if you have an overall smaller 17 but you have a lot more rubber and is wider than the 16's, the increase in mass is gonna require more power.
theres a science experiment in skool where you roll a rim and a solid wheel of the same mass down a ramp and the solid wheel always wins. or something like that.
theres a science experiment in skool where you roll a rim and a solid wheel of the same mass down a ramp and the solid wheel always wins. or something like that.
that makes a lot of sense. which is why i'm gonna put the stock rims back on next time i get the car dyno'd. maybe in a few weeks. if nothing really changes, i'll give rrm a call. hopefully i'll get a chance to get to the track also in the next couple of weeks. thanks for all the helpful input guys.
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From: TB, FL
Originally Posted by amg_dragon
This is why people spend so much money on lightweight rims, it has to do with rotational mass. Try spinning a bucket 1/4 full of water and then do the same with one 1/2 full... Remember that hp and torque are relative to the amount of weight being "pulled". Now before anyone gets jumpy and says weight doesn't affect hp, remember that the factory dyno's the engine on a stand and NOT in a car, where the rotating mass is a predetermined constant. Higher weight wheels affect performance, everyone knows that, I'm just trying to explain why. If you really want 18's on a RA spend that much more and get lightweight ones if you want performance to go with it. I put my 17's on and realized that my stockers weighed less. I could feel that the car was slower, I didn't need a dyno to confirm it. Hope this helps.
Of course, there is an exception to the rule: When you start making crazy HP/TQ figures, you obviously need bigger tires to get grip. It's no good burning up the line and going nowhere.
Example:
3 inch sprocket vs 8 inch sprocket . . . both having the same weight. Which will spin faster?
3 inch sprocket (5 lbs) vs 8 inch sprocket (2.5 lbs). Which will spin faster?
Again, it takes less overall effort for a machine to turn crazy rpm for a 3 inch sprocket.
BTW: When you get bigger tires, you have just added more weight over stockers, even with lightweight 18's, performance will be offset.
Please don't tell me about drag radials or slicks = no one drives them in all climate factors, unless a trailer queen.
Last edited by bahamut; Apr 3, 2005 at 03:45 PM.
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From: Anderson, SC
so even if the 18" rim/tire combo weighs a little less than the stock rim/tire combo, it will still have a negative effect on the dyno because the 18's have more mass making it harder for the engine to turn them? it makes sense to me. it kind of pisses me off though because the guy at the shop said it shouldn't make a difference and if it did it would be so small you wouldn't notice. well, i noticed alright!! back to the dyno with the stock wheels then or maybe i'll just try to fine some similar wheels in 16's.
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From: A
Originally Posted by coote
so even if the 18" rim/tire combo weighs a little less than the stock rim/tire combo, it will still have a negative effect on the dyno because the 18's have more mass making it harder for the engine to turn them? it makes sense to me. it kind of pisses me off though because the guy at the shop said it shouldn't make a difference and if it did it would be so small you wouldn't notice. well, i noticed alright!! back to the dyno with the stock wheels then or maybe i'll just try to fine some similar wheels in 16's.
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From: Anderson, SC
gotcha. back to 16's i go for sure then. only reason i got the 18's in the first place is i got them for a good deal. $700 for rims and tires....i didn't think that was too bad. i'll see if i can trade them back in for some 16's or something. i'd much rather have performance over looks anyway.
Originally Posted by jamie
there was a show i watched i believe it was sports car revolution rsx i believe they dynoed stock modded the car with big brake kit and lost power due to bigger rotating mass of the brakes
Don't know if it has already been posted but the RSX lost 12 whp from the wheels and big brake up grade kit. The WHEEL/tire combo weighed exactly the same as the stock ones.
They said the power loss was due to the rolling mass being further out on the circumference of the wheels thus requiring more power to turn the wheels.
WADAD
are you all assuming that someone /w 16's are using 45 high tires and larger wheels are using a smaller tire to keep the difference in overall size as close as possible? I dont see how saying that using a 17" wheel will make the car have less HP because of the 'size' when 16" + 45tire is almost the exact same 'size' as 17" + 40tire.
And if hes 17" tires are 2 pounds lighter than the stock 16" tires, they are probably lighter, per area, han the thick rubber, as well, thus saving more over-all weight than the set 16's. That said, with the situation you discribed with your tires, they should give you and ADVANTAGE on the dyno and not be the cause of any hampering. the distance from the center of the wheel to the point of contact with the road should be the same.
however, wheel width is another issue. if you are using 215's, you may lose some low torque, but gain some peak torque. HP should not really be effected at peak by your width, though. But, wider wheels will let you launch higher and hook faster on a 1/4. so even though the dyno #'s look worse, the track #'s should look better /w a lower 60'.
and like i said before, recheck the dyno results. the dyno is only as reliable as the person strapping it down. if it was strapped differently, the results will be different. re-run. see what happens. make sure your intake isnt caked with mud or something =)
And if hes 17" tires are 2 pounds lighter than the stock 16" tires, they are probably lighter, per area, han the thick rubber, as well, thus saving more over-all weight than the set 16's. That said, with the situation you discribed with your tires, they should give you and ADVANTAGE on the dyno and not be the cause of any hampering. the distance from the center of the wheel to the point of contact with the road should be the same.
however, wheel width is another issue. if you are using 215's, you may lose some low torque, but gain some peak torque. HP should not really be effected at peak by your width, though. But, wider wheels will let you launch higher and hook faster on a 1/4. so even though the dyno #'s look worse, the track #'s should look better /w a lower 60'.
and like i said before, recheck the dyno results. the dyno is only as reliable as the person strapping it down. if it was strapped differently, the results will be different. re-run. see what happens. make sure your intake isnt caked with mud or something =)
Originally Posted by blk-majik
are you all assuming that someone /w 16's are using 45 high tires and larger wheels are using a smaller tire to keep the difference in overall size as close as possible? I dont see how saying that using a 17" wheel will make the car have less HP because of the 'size' when 16" + 45tire is almost the exact same 'size' as 17" + 40tire.
And if hes 17" tires are 2 pounds lighter than the stock 16" tires, they are probably lighter, per area, han the thick rubber, as well, thus saving more over-all weight than the set 16's. That said, with the situation you discribed with your tires, they should give you and ADVANTAGE on the dyno and not be the cause of any hampering. the distance from the center of the wheel to the point of contact with the road should be the same.
however, wheel width is another issue. if you are using 215's, you may lose some low torque, but gain some peak torque. HP should not really be effected at peak by your width, though. But, wider wheels will let you launch higher and hook faster on a 1/4. so even though the dyno #'s look worse, the track #'s should look better /w a lower 60'.
and like i said before, recheck the dyno results. the dyno is only as reliable as the person strapping it down. if it was strapped differently, the results will be different. re-run. see what happens. make sure your intake isnt caked with mud or something =)
And if hes 17" tires are 2 pounds lighter than the stock 16" tires, they are probably lighter, per area, han the thick rubber, as well, thus saving more over-all weight than the set 16's. That said, with the situation you discribed with your tires, they should give you and ADVANTAGE on the dyno and not be the cause of any hampering. the distance from the center of the wheel to the point of contact with the road should be the same.
however, wheel width is another issue. if you are using 215's, you may lose some low torque, but gain some peak torque. HP should not really be effected at peak by your width, though. But, wider wheels will let you launch higher and hook faster on a 1/4. so even though the dyno #'s look worse, the track #'s should look better /w a lower 60'.
and like i said before, recheck the dyno results. the dyno is only as reliable as the person strapping it down. if it was strapped differently, the results will be different. re-run. see what happens. make sure your intake isnt caked with mud or something =)
The dyno proves that the car looses whp even when the weight of the wheels and circumference stays the same.
As for your track comparison with being able to launch higher, I would run any other MT OZ, ES lancer any day that had rims on it. If they were able to get a jump on me I am sure I would run them down in the higher rpms when my stock wheels allow my car to pull itself out of the deficit. The rims debate is one reason I have yet to put any on mine.
WADAD
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From: A
Originally Posted by blk-majik
are you all assuming that someone /w 16's are using 45 high tires and larger wheels are using a smaller tire to keep the difference in overall size as close as possible? I dont see how saying that using a 17" wheel will make the car have less HP because of the 'size' when 16" + 45tire is almost the exact same 'size' as 17" + 40tire.
And if hes 17" tires are 2 pounds lighter than the stock 16" tires, they are probably lighter, per area, han the thick rubber, as well, thus saving more over-all weight than the set 16's. That said, with the situation you discribed with your tires, they should give you and ADVANTAGE on the dyno and not be the cause of any hampering. the distance from the center of the wheel to the point of contact with the road should be the same.
however, wheel width is another issue. if you are using 215's, you may lose some low torque, but gain some peak torque. HP should not really be effected at peak by your width, though. But, wider wheels will let you launch higher and hook faster on a 1/4. so even though the dyno #'s look worse, the track #'s should look better /w a lower 60'.
and like i said before, recheck the dyno results. the dyno is only as reliable as the person strapping it down. if it was strapped differently, the results will be different. re-run. see what happens. make sure your intake isnt caked with mud or something =)
And if hes 17" tires are 2 pounds lighter than the stock 16" tires, they are probably lighter, per area, han the thick rubber, as well, thus saving more over-all weight than the set 16's. That said, with the situation you discribed with your tires, they should give you and ADVANTAGE on the dyno and not be the cause of any hampering. the distance from the center of the wheel to the point of contact with the road should be the same.
however, wheel width is another issue. if you are using 215's, you may lose some low torque, but gain some peak torque. HP should not really be effected at peak by your width, though. But, wider wheels will let you launch higher and hook faster on a 1/4. so even though the dyno #'s look worse, the track #'s should look better /w a lower 60'.
and like i said before, recheck the dyno results. the dyno is only as reliable as the person strapping it down. if it was strapped differently, the results will be different. re-run. see what happens. make sure your intake isnt caked with mud or something =)