Hello all,
I am new to the Civic world (had a GSR for 7 years, though) and I am buying a 91 DX shell into which I will put a D15B2 to go SCCA racing in ITA, and HC racing in H5. Since the motor is a little, shall we say, down in hp, I figure it would need all the help it can get.
So, can ya'll tell me what my best bets are for:
- intake (AEM?)
- header (DC?)
- flywheel

anything else I can do to make the ol' D15 go a wee bit faster? No forced induction or NOS. The mods allowed are pretty limited, although I have not received the rule book yet. Anyway, any help will be appreciated.
thanks in advance.

 

if you are allowed to the MPFI swap is almost a must. the DX's DPFI almost wont react at all to the mods you have listed.

 

No, I am pretty sure I have to stay with the DPFI. I guess it'll be cheaper, eh? Stay with the stock parts? Although a lighter flywheel will help, regardless of the injection type. Who makes a lighter flywheel for the D15B2? It didn't look like Fidanza had one?

 

you could always change the valvesprings and cams.

 

Do you have to stick with the engine that came with that trim or can you go with any motor as long as it was offered in the same car but different trim?

I'm asking because the D15 is a dog. It would be MUCH better to go with the Si D16A6... assuming you want to be competetive.

 

yup, I have to stay with the engine and tranny that came with it. That means D15B2 and 5-speed (at least, it's not the B1 and 4-speed...) - at least for the classes I want to race in (ITA, G-prod and H5)
Most of the speed will come from the light weight, suspension and mad skillz anyway. I just was hoping to optimize whatever the ol' D15B2 could do. Nothing internal, just I/H/ and open exhaust.
Again, anybody know of a light weight flywheel? or do I have to take the stock one to the machine shop and have it shaved?

thanks for the input guys.

 

I could be wrong on this but wouldn't a flywheel made for D16A6 Si engine work? And be "legal" race-wise? It's the same block as the D15.
Although the cranks bolt pattern to the flywheel might be different.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 4crx4me &raquo;</TD></TR><TR><TD CLASS="quote">I could be wrong on this but wouldn't a flywheel made for D16A6 Si engine work? And be "legal" race-wise? </TD></TR></TABLE>

For SCCA ITA flywheels must remain stock.

I say just take the car to SMSP.

 

First off, the DX transmission is way to high geared for RR, Internally they're the same as the Si except the Si has larger diff bearings and a lower FD. If there's any way to sneek an Si tranny in there it would definately be worth it. If you get a new tranny, make sure to get one from a 89-91, the 88 tranny has a different spline count than the 89 up and you'll be stuck with the smaller 88 clutch disk (there's a way around it, but it's easier to just get the newer tranny)

As .RJ said, lightened flywheels are a no no in the class you're looking at, but just so you know, any d-series civic from 90-2000 has the same flywheel. so you could (if it was legal) put a flywheel designed for an Si in there.

You are absolutely going to HATE the DPFI intake manifold!!!! the throtle body is so small and restrictve, you are going to have no throtle responce!! If you want to build a car that's even close to competitive, I'd say the must-haves would be an Si MPFI intake manifold, Si cam and valvesprings, and Si FD gears. the car will accually be fairly peppy with these mods, but then you'll have to see what class it goes in from there.

Put a sunroof in it and call it an Si.