Is an ITR flywheel it's own unique unit, or is it just a lightened version of the GSR flywheel?





Modified by hypa at 5:15 PM 7/27/2004

 

research that and get back to us.

 

must I do everything myself?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hypa &raquo;</TD></TR><TR><TD CLASS="quote">or is it just a lightened GSR flywheel?
</TD></TR></TABLE>

Erugh? All I know is the R flywheel is 15 pds. Never new GSR was a lightened flywheel

What do I know? I've never driven a R motor with an R flywheel ever! Why? I dunno, I changed it ASAP?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ki3t &raquo;</TD></TR><TR><TD CLASS="quote">Never new GSR was a lightened flywheel </TD></TR></TABLE>

I think he was just asking if the R flywheel was just a lighter version of the GSR flywheel.

btw, isn't the gsr FW like 17 or 18 lbs.?

 

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

I think he was just asking if the R flywheel was just a lighter version of the GSR flywheel.

btw, isn't the gsr FW like 17 or 18 lbs.?</TD></TR></TABLE>


That's exactly what I was asking.
Being that a lot of the ITR parts started life as P72 units, then had the hands of Soichiro's ghost massage them into teh eliteness. Factory GSR unit is 18lbs, whereas ITR is 14 lbs.


It would make sense for Honda to lighten a P72 flywheel, then shot peen it like they do with the rods. It would allow them to keep costs down, but most of all it would give me more info on the reliability of lightened flywheels for NA applications.

FYI, I'm using an ACT streetlite, but I know of a few people who run ITR fw's.

 

here's something interesting.

above is a pic of an ITR fw (thanks to 00-ITR-373 )

Same as the standard B series Honda flywheels, it only has 6 pressure plate mounting bolts, and is virtually the same shape, same casts, etc.


Below is a jdm b16a flywheel.
IT looks virtually the same as the ITR unit, but has 9 mounting bolts for the clutch pressure plate.


wierd ****.

 

aftermarket fw's have 9 PP mounting bolts.

 

bump for more info.

 

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

aftermarket fw's have 9 PP mounting bolts.</TD></TR></TABLE>

I'm thinking because maybe they fit for B-series civics too which require 9 bolts? Just a thought.

 

B series flywheels are held to the crank by 8 large, fine thread bolts. The clutch pressure plate is held on with either 6 bolts, or 9. I've been going through some old flywheels, and posts here and have found that the P30 flywheels have 9 clutch mounting bolts, while the GSR/ITR only have 6.

That's why the guy at Acura looked at me funny when I ordered 9 of the clutch mounting bolts.

 

So what do my fellow ITR owners recommend on a stock ITR engine? My research results that basically stock is better for torque and lighter is better for acceleration. Is it even worth upgrading and what do you have on yours? (looking to purchase within next couple days) Thanks all.

 

Not sure where the myth about losing low-end power came from, but it's stuck around a long time. A lightened flywheel reduces rotational losses by a certain fraction. So lightening the flywheel increases wheel torque by a certain (small) percentage. Basically, the faster you accelerate, the more noticeable the benefits are. A dyno would show several ft-lbs gained in 1st gear, with less in 2nd, less in 3rd, and so on.

I had an 8 lb flywheel on my GS-R for years, and I loved it. For me there were no downsides: rev matching was easier, even during daily driving; the engine tached up more quickly during starts; and the extra acceleration in 1st and 2nd was a bonus. It's easier on the clutch, too.

However, the lighter the flywheel the more likely it will chatter. So if you have a really stiff clutch, or wear or warpage that will be more of a problem. And some people simply don't like the feel of a light flywheel.

None of this is ITR specific, but my general recommendation is to go as light as possible, unless you think subjectively you'd prefer a heavier one. Fidanza makes a popular 7.5 lb flywheel, and Exedy makes a high quality one-piece 9.5 lb that I've just put on my car to replace the Fidanza.

 

I think what a lot of people are confusing this whole time is the difference between torque and inertia.

Because of the reduction in inertia the car can be more difficult to drive for some who are used to having revs hang just for that split second longer between shifts. This can also affect how the car responds for those who live in really hilly areas when doing standing starts. This can be solved with judicial use of the e-brake to hold the car without slipping the clutch unnecessarily.

Personally, I went with the lightest possible but went even a step further with lightening the whole clutch assembly with an ATS carbon super single. This reduces the weight another 2-3lbs over a stock style clutch + Fidanza.

I did however use it in conjunction with a 4.785 final drive to regain some of that lost inertia for standing starts - making drivability virtually imperceptible vs. the stock setup.

The acceleration vs. the stock car became very manic and overall magnified the Rs inherent character without too many (if any) unfavorable downsides.

 

Good info and well said.

 

Thanks for the quick and detailed responses. I searched the Spoon racing flywheel which is 9.5lbs and they state it's that weight because they side want to go TOO light. Not that I would considering buying Spoons flywheel being that it's $400 but a company such as that didn't recommend lighter than that. What I am replacing is a comptech 7.5lbs flywheel which seemed great but I don't have experience with the heavier stock one to compare it to.

 

where do you get comptech parts? When CT-Engineering bought out comptech its like they dont ever manufacture parts for integra anymore because of the k-series.

 

as stated earlier, it's good to consider the weight of the entire rotating assembly. it's like how some people care about the weight of the wheels but totally forget the weight of the tires (which are even further outside).

The one negative of a light flywheel or setup is the lack of inertia. more chatter, easier to stall, could also be a reason for a more erratic idle too.

 

The previous owner who purchased the car new had the Comptech flywheel installed sometime before 2009 before I had the car.

 

As people have said the main problems you can get are 1) chatter, 2) rough idle, 3) peaky power delivery, 4) higher rpm needed on starts. I personally never had problems with any of those, but if you are, you might go to a heavier flywheel. In a few days (hopefully) I'll be done with my swap, and I'll have done from a 7.5 lb flywheel to a 9.5. I'll report back here if you haven't already made a decision.

For Spoon the "lightest possible" may be the lightest possible on a 1-piece steel design. Most of the lighter ones I know about are aluminum assemblies with steel friction surfaces bolted on. Or it could be marketing speak, lol.

 

I can personally verify this is correct. I have an OEM 00 spec ITR flywheel I weighed.

Lightweight flywheels are nice... After wanting to daily drive my car more, I found the revs to drop too quickly than I preferred with the 7.5lb flywheel.... the 12lb flywheel is just right.