Just wondering b/c I'm dynoing my baby tomorrow, and I'm currently running 17" wheels with 215/40 17's. It's about 0.3" taller than stock, and each wheel with tire weighs about 42 lbs.

Is it affected, if so....by about HOW MUCH ?????

Thanks!

-on a side note, anyone know the weight of stock wheels with tires?? (or at least the weight of the wheels themselves?)


Modified by typeruz at 2:10 AM 10/11/2003

 

anyone?

 

you may lose like only 1-3hp. stock is like 36lbs ish

 

THANKS!!!

 

That's about 10 lbs heavier than my old stock wheel/tire combo.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by typeruz &raquo;</TD></TR><TR><TD CLASS="quote">each wheel with tire weighs about 42 lbs.
</TD></TR></TABLE>

 

It's been a while ago when I read this article in SCC where they took a Civic SI & put it on the dyno. They added 1 thing after another...turbo, exhaust, pulleys, you name it. The dyno #'s started to climb & then fell when they added the 17" whs & tires. To my suprise they fell a little more when they added an AEM big brake system. A 6 or 7 HP loss. Just remember any extra rotating mass takes that much more HP away from your dyno run.

 

yes you will. i read the same scc article and the drop was around 3-6hp through the entire rev band.

bigger wheels will give lower hp numbers but will handle better.

 

Just remember to have the same wheels on the car the next time you dyno it/tune it so you get an accurate before and after reading.

 

Depends on the dyno. If it's a dynapack, wheels are removed.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by georgiajdm &raquo;</TD></TR><TR><TD CLASS="quote">

bigger wheels will give lower hp numbers but will handle better. </TD></TR></TABLE>

?? i dont think so

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by George Knighton &raquo;</TD></TR><TR><TD CLASS="quote">

I'm thinking you're talking about his comment about the handling.

If you're going from 6" wheels and 195 010's to 7" wheels and 225 Hoosiers, it is really irrelevant if the diameter is 15" or 17".

In most circumstances, when most people change to a larger diameter wheel, they are also getting wider wheels, putting more rubber on the ground, and putting <u>better</u> rubber on the ground.

Theoretically, you're right.

You could cause handling to decay by changing wheels like that, but in most cases the handling is improved. </TD></TR></TABLE>

ya, given equal width of rims and tires, i am pretty sure the 17s aren't better than 15s...thanks for clarifying though

i am pretty sure he didn't consider the width part though...if he did, he would've been more clear

 

stickier tires also affect dyno results.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by all stock &raquo;</TD></TR><TR><TD CLASS="quote">stickier tires also affect dyno results.</TD></TR></TABLE>

lol, you mean if I dyno with slicks I get higher results?

and about the tire/handling: doesn't sidewall have any effect on handling too? just curious.

EDIT: sidewall, always get that mixed up with firewall.


Modified by Calavera at 7:17 PM 10/13/2003

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Calavera &raquo;</TD></TR><TR><TD CLASS="quote">and about the tire/handling: doesn't firewall have any effect on handling too? just curious.</TD></TR></TABLE>

Firewall?

 

Theoretically, it shouldn't influence the power output of the engine. If it's measured with an acceleration dyno, it will affect measurement very very little because the drum is much heavier.
But if you use a brake dyno (constant rpm), you won't see the difference.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Reid &raquo;</TD></TR><TR><TD CLASS="quote">

Firewall?</TD></TR></TABLE>
Hahahaha, I think he meant sidewall.....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Calavera &raquo;</TD></TR><TR><TD CLASS="quote">

lol, you mean if I dyno with slicks I get higher results?

and about the tire/handling: doesn't firewall have any effect on handling too? just curious.</TD></TR></TABLE>

stickier tires reduce dyno hp. more friction.