I've seen a lot of posts comparing different motors but i've never seen a jdm b18c vs a usdm b18c5. I currently own a jdm b18c which is a very good motor and i do like it a lot. But i must admit i rather have gotten the c5. A lot of people tell me that my motor is very similar to the c5. From what i've heard the tranny is the exact same thing. I do have LSD and 10:6:1 compression just like a ITR. As far as i know the only difference is the head.

Well there's 2 questions that i'm asking. I just want people to compare the two motors.

The second question is does anyone have a c5 head on a GSR. I've been thinking about doing this for a while. I'll have a better flowing head, better cams, better manifold, but i just wanna see if anyone has it and what they think.

thanks

 

You have a JDM B18c? Is that the B18c R or B18c GSR?

There isn't much of a difference between the usdm and jdm itr motors. The JDM tranny has a 4.785 Final drive, and the usdm is smaller I believe. As for other stuff, I'm not gonna say.. I'm not 100% sure whethere it's true or not.

 

I have a JDM b18c which is the GSR motor. the head of my motor says p72, so it's a GSR.

 

ITR engine come partly hand built the crank bolts, they have a lightened flywheel its like 4lbs lighter, and like you said cams, better flowing etc....

 

There are a bunch of differences. The only thing that it shares with the USDM ITR motor is the compression ratio and the same helical (sp?) type LSD.

The gearing on the trannies is very different. The motor that you have is basically a USDM GSR motor with higher compression and an LSD tranny.

 

So the only similarity between the c5's bottom end and the JDM GSR is the compression. The pistons or rods have nothing in common. I know the gearing is not the same as a GSR. The first and second gear might be the same but after that it has to be different. I could be wrong so correct me if i am.

What do you guys think about putting a ITR head of this motor. Am i better off just working on the one I have?

 

Actually, just a B18C doesn't tell us whether it is a SI-R/GSR or the ITR. Both engines received the B18C identification number.

I have a B18C GSR with I/H/E, and I have been debating about swapping for a JDM ITR longblock or just completely rebuilding the head. It is a little cheaper to swap the longblocks, but if I went with a complete head rebuild, I would basically have a newer head.

It is about 4000 for me to completely rebuild the head, and that includes machine work, parts, fuel management, and labor. How much does a complete B18C5 head go for?

 

damn 4 grand is quite a bit. i hope you gained some serious power from that. I'd like to know exactly what you did to the head. Here's what i figure. The main difference is the head. Obviously there are a lot of differences between the 2 motors but the main difference is the head. So if i have 180 hp stock, and then if i put a ITR head there should be atleast 15hp in that mod right. Considering i would have a better flowing head, better manifold, better cams, and i would rev higher.

 

I haven't actually gone through with the head build up, but I have been pricing it out. I have basically been referring to Import Builders, who would probably do the complete build which would include: "IB Spec" head package, Hondata S100, Skunk2 Intake Manifold, NA Hondata Tuning, and labor. After tax, that is close to about 4 grand. Horsepower is not cheap! IB claim they have NA cars with this same setup that make 210+ whp!