RCFormante

iTrader: (1)

I'm back from hiatus, with some fun with Gearbangin! 10 Runs below!
Runs 1-4 from a dig 1/8 mile and runs 5-10 from 60 MPH roll.
ISF has full bolt ons, my RCF has intake and exhaust.

My PPE Headers are coming soon!

4everkidd

iTrader: (2)

looks pretty dead heat!

I'm not surprised, but my RCF still *feels faster than my full bolt on ISF's

Ryanmcd

That ISF sounds great, I cant wait to hear some RCF's with headers on them

05RollaXRS

He is running larger circumference wheels. That has lengthened his gear ratios, which in turn typically hurts acceleration.

I would recommend going with lightweight 19 inch wheels close to the stock circumference in order to retain the same gear ratios as stock.

ISF001

All scientific comparisons for any cars are significantly skewed from spec performance when the cars are modified from stock.

Is it fun? Sure, but the basis of comparison is now based on add ons and not the cars as originally manufactured.

As originally manufactured, we know how this comparison will more often than not end. Otherwise, add NOS shots to the equation for complete distortion.

A stock RC F versus a stock IS F:

MRxSLAYx

Bad recommendation... You've been told many times that his wheel and tire setup are much lighter than the factory equipment.

Joe Z

iTrader: (10)

I thinking he's bringing up rolling diameter... (not weight)

The RC F oem rear is set up with 275/35 on 19x9.5

If he wants to know if his current setup is hurting performance / shifting / gear ratios at the track, he can use this simple calculator to compare:

https://www.tacomaworld.com/tirecalc

Or

http://www.rimsntires.com/specspro.jsp


Joe Z

MRxSLAYx

What im saying is that a longer gear will not hurt is performance if the wheel/tire combo is light enough. My ISF traps 2mph faster (runs were less than 30 mins apart) with a tire combo that weighs 8~10 lbs lighter but is over an inch taller than factory. Ill look for the post where the owner tells us his specs, but I believe he said its over 100lbs of rotational weight savings for the whole car.

05RollaXRS

What? Bad recommendation? Are you kidding me? Stock overall circumference with lightweight 19 inch wheels is a bad recommendation? That is absolute laughable. What I said was, in order to maximize the benefits of lightweight wheels, stick with the stock circumference. It can only be better than a larger cicumference wheel/tire combo.

Plus, the tire weight is the other half of the equation. A bigger tire of equivalent type is typically heavier than a smaller tire unless it is significantly lower profile. If the larger tires are of the same/lighter weight than the OEM MPSS then I would like to know the model/brand and size of the tires and it is easy to verify the weights vs OEM. Until then, I believe the total tire/wheel combo put together is not lighter than the the OEM combo.

Some of you ISF owners never cease to amaze me

Joe Z

iTrader: (10)

I totally get what your saying..

But the weight is not a dictator on how the car shifts down the 1/4 mile from a stand still...

Granted it may be lighter.. But that does affect engine rpm, gears used & trans shift points ..


~ Joe Z

MRxSLAYx

I know what you're saying and its a bad recommendation IMO because a 19 inch wheel wont really make a significant difference if looking for performance. Limited wheel choices that are high quality and noticeably lighter and little to no tire choices. I fully understand what you're saying about maximizing the benefits of a lightweight wheel, but what im saying has been proven many times over.

Im not even going to seriously respond to this after reading your signature.

I completely agree, Im just saying that a lightweight 18inch wheel and taller tire (DR to be ideal) is going to make a positive difference.

Gearbangin

iTrader: (7)

Here is the other angle..