But my point is, you cant say "you should have 15 more horsepower", because every dyno reads differently. He could go onto another dyno, and it say he made 25 more horsepower, then another one say 5 less. There is no way to calibrate a dyno to make it accurate either.

 

Let me tell you somthing, if you are having an influx of 25 hp then that means somebody isn't doing something right if you havn't done any mods to the car or that means that you are having some serious engine issuses. You should only have an influx of 5 hp like I said, and that doesn't mean that is your max hp 125 you could hit 130 the next time, that means that if you are 125, then your adverage is 122.5, so that means you could go down to 120, or up to 125, an influx of 5 hp, or at least that's what I experianced, but I did 20 pulls and I never went below 120, infact, I only hit that one time, I mainly hit 123 or so, but I did hit 124 and 125 a couple of times, but if I go to another dyno, I should get exactly the same numbers as long as the person knows what they're doing and they have a good computer.

 

you can have a car which makes exactly 150rwhp, but one dyno will say 145 and the other will say 140, it doesn't matter. a dyno is not a tool for finding an absolute number, just a tool for comparing one run to the next. you can't compare results from dyno A at time X to dyno B at time Y because there are a trillion variables between each one. even the ambient air temperature and humidity will change your HP #'s.

 

I wasn't refering to you Jthorn... I was just refering to him. There was a guy who posted dyno numbers a couple weeks ago with fewer mods that was putting down around close 180hp. Maybe I read wrong. And I do agree, dyno #'s aren't perfect, but they're also not 25hp off from dyno to dyno.

 

tell that to Andy from TMA

the weight of the wheels used affects Dyno#'s tremendously

lighter wheel=freeing up hp

i'm pretty sure Sai's car picked up about 20+rwhp on tma's dyno session with 15 inch stock rear tires instead of his 18"

 

20 hp with just a wheel change[sm=icon_rofl.gif][sm=icon_rofl.gif][sm=icon_rofl.gif][sm=icon_rofl.gif][sm=icon_rofl.gif]............catches breath, yea, maybe if they were made of gold. The weight of the rims is not a big factor because remember, a smaller set of rims uses more rubber for the tires than bigger rims, so the weight should average out. I could posibly see a 1-2 hp difference, but deffinitly a 20. Yea, your right, there are tons of variables that affect hp, but point is, there is no varible that occurs in your area that could cause you to have 150hp today, and 180 hp tommorow, and 130 hp yesterday, like I said I can only see an influx of about 5 hp under normal cercumstances, and maybe an influx of 10 hp maximum is you do a run in Florida in July, then do a run in Montana in December, but outside of those two variables, then end result should always be approximately the same.

 

My new rims are really light

 

did you know that rubber wieghs a lot less than certain metal alloys? and you don't need to take a lot of rotational weight out of your car to make a big difference. have you ever driven a car with normal rims and then driven it with 20" rims or something like that? there is a big difference. HUGE difference. drive a tahoe with stock rims vs. dubs and it's like night and day. you'll feel like the brakes can't stop the damn thing when you add huge rims, and it works the same way for acceleration. and with the larger rims, you're putting a large amount of the mass (the rim of the rim) far away from the rotational center of the wheel, so it's even harder to turn the wheel.

 

not to jack thread,what all do these test/change in a tune-up from regular old shop......air/fuel ratio,check computer,what else?

 

Well rubber does weight less, but there is more than rubber in the tires, there are tons of other materials, and I'm talking about lightweight wheels, not those heavy steal rims with a chrome clearcoat. But have you ever picked up a tire for a 16" rim, they're not exactly light, so the larger rim does weigh more, of course, but uses less tire so the weight shouldn't be too sever, not saying that it isn't possible to have a rear wheell hp increase, I'm just saying that if you have 17" rims and you drop to 15", I don't forsee a huge difference, now 15" compared to 20", yea that's a big difference.