I've tried contacting RS Machines a couple times now with no response.

I'm trying to find out the compression height and dome cc for their pistons, specifically the flat, domed, and ITR pistons.

With respect to the ITR piston, is it a copy of the JDM ITR piston, or the USDM ITR piston?

Thanks in advance.

 

I believe its a copy of the us type r piston.

What CR do you want to be at?

 

Roughly 11.5:1

 

What block do you plan on using? your cr will vary with the different cranks, slugs, head, etc.

Ever use a compression calculator?

 

I've been using the Zeal Autowerks calculator.

B17, 82mm bore with a P72 head.

JDM ITR = 11.53:1
USDM ITR = 10.97:1

JDM B16 = 11.47:1
USDM B16 = 11.24:1

 

His itr pistons are usdm replicas. Best way that I know get ahold of him is through ebay user name droopie888

 

yea so rs itr replicas will be just what you want

 

rs machine is not droopie on ebay but he does sell their products and that would be the best way to buy them.

 

why you dont try nippon racing pistons, i believe they are replicas of jdm itr's, and their products are not that expensive and hey they are also proven....i have heard bad reviews from rs machine customer service....

 

nothing against rs machines, i had a block sleeved by them a few years ago but you should try the nippon or ycp pistons. to tell you the truth i wouldnt be surprised if they all come from teh same manufacture but just slap a different brand name on the box. the ycps and nippons can be had for a hundred bucks less sometimes

 

Did two builds with RS pistons, neither with a problem

And this is the first I heard of RS having any problems and they've been "proven" many times to be adequate

 

Generally the ratios that Zeal give you tend to be .2-.3 higher than actual so keep that in mind.

 

Out of the few out there, which calculator is most accurate

 

None. They are all ball park figures. Unless u measure ur set-up and put in the info yourself which obviously is the most accurate.

 

Zeal has some cool "more precise" features but I find the C-speed racing calculator to be more accurate if you will. They are all guides really and work off of assumptions, you'll find that when you start measuring things that actual dimesnions will be different than some of the assumptions.

 

the math is correct on those compression calculators, its the specs that are off.

 

How are the RS ITR replicas what I want if I'm aiming for 11.5:1?

I'll have to look in to this. If they are in fact JDM ITR copies, they will likely be the piston I go with.

I currently have a C1 with RS ITR pistons...no problems what so ever.

Good to know.

Thanks for all the help guys.

 

RS machine ONLY makes copies of USDM pistons. Thats why they dont sell P30's, Just PR3's.
The stamp on the ITR pistons is P73-A0.

OP if you cant find the JDM ITR's I know you can get the P30's in up to a 81.5 bore on JHPUSA.com which will be the closest to the JDM ITR slugs CR.

 

Thought u said 11:1 initially