I'm rebuilding my 99 GSR B18C1 motor (block) with piston, rings and rods. What would be better between the CTR (10.8cr) and the JDM ITR (11.1)??? Would the higher compression better or not worth it and the ability to rev higher...

 

If the CTR pistons are higher compression, you'll get a bit more power out of them. I'm not sure how much difference a .3 will make, but there's a certain compression ratio you want to stay under for the street.

Built properly, you'll be able to rev just as high with either piston. If it were my motor, I'd go with CTR.

 

CTR goodness in my B18C1 block (soon to be replaced with an IB spec 2.0 litre)

 

http://www.c-speedracing.com/howto/c...c/compcalc.php

 

FYI
ITR = 11.1:1
CTR = 12.2-12.5:1 in b18c block

 

Here's a related question about these two pistons... does the difference in mass (I have seen that the CTRs are somewhat heavier) make a performace or reliability issue? Does the increased CR make up for (or more than make up for) the greater mass in the case of CTR pistons?

 

And then some. but you have to know how to put that compression to good use

 

IS THAT WITH THE TYPE-R HEAD OR GSR?

 

b16a/itr

 

Thanks for the great cr calculator link... With CTR pistons in a B18C1 block and head, it would give me 12.04 cr. Would this be too high for a streetable car(everyday driver)?

 

No, I am running 12.4:1 on pump (93 octane) gas. I think others on the board are running more compression on pump gas. Key to running correctly, and reliably is in the tuning...


Jason

 

i only have 92 where i live

 

that calculator is wrong when dealing with ctr pistons.
b18c crank and head will make 12.5 or so

 

That's what I think too...should be up to 12.5:1 eh...?

 

What cams are you going to be running?

 

is the ctr pistons just bolt on or any monification on gsr rods? if you have gsr rods?

 

I was wondering if you could elaborate on that.. Do you mean tuning, or the right combination of cams, induction, header, porting, etc..

 

I haven't got any cams or cam gears yet. I'm planning to get CTR cams.

 

Oh...........12.5:1.........it's base on stock 3p gasket or 2p?
I'm going to put the PCT in my JDM B18C R engine........what's the correct compression if I'm using stock 3p gasket & 0.8mm Toda gasket?
Toda 0.8mm gasket only got 81.25.