Exhaust Notes

Our #1 Most Often Asked Question, Should I Boost?

I have a '91 Integra with the basic mods, which are headers, exhaust, intake, cams, throttle body and ignition. I want more power (from a turbo) but I still want to pass California smog. Is this possible? And if so, which turbo? Or would a supercharger be my best bet?

-Gary B / HT Inbox

There are two answers. The first deals with reality, the second a hypothetical world. The first answer: Unfortunately, you're out of luck. The CARB-legal GReddy and Edelbrock turbo kits and Jackson Racing supercharger kits you've probably heard of are legal only for '94-'01 Integras, not older, pre-OBD models. There's simply no smog-legal turbo kit you can put on your car and then waltz into your local California smog shop and expect to pass visual inspection. Sorry.

The second answer: Fortunately, such turbo kits will bolt onto your Second Generation Integra's B-series relatively easily. With a bit of intercooler piping modification and creative wiring, they'll both work. And to the not-so-keen smog station employee, those CARB-approved stickers just may appear to belong, but this is all hypothetical. The nice thing about turbocharged vehicles and California smog testing-if there is such a thing-is that they're loaded onto the smog dyno in such a way that doesn't allow for engine speeds high enough to produce boost. Test procedures include part throttle runs at 15 mph and again at 25 mph. If you're making boost here, well, you won't be. So hypothetically, there's no reason for a well-tuned turbocharged Honda to not pass your basic California emissions test, whether you've got an '01 or a '91. More often than not, testing failures are due to improper tuning and important missing parts like catalytic converters and charcoal canisters. But again, this is all hypothetical.

-Aaron Bonk, Technical Editor, Turbo Magazine

D-Box on B-Block?

I have a '91 Honda CRX with a d15 non-VTEC motor and I have a B16A to put in it. I was wondering if the transmission that is already in my car would bolt up to my B-series motor?

-Bryce Parisien / Williston, N. Dak.

The short answer is, no it won't. There are some companies, like Bisimoto Engineering, that are making adapter plates to bolt the H-series engines to the B and D-series transmissions but not for B-series engines to D-series transmissions. To get the two to bolt up would require at a minimum, a custom flywheel, custom transmission adapter plate, custom driver's side mount and alternator relocation. Unless you can do the fabrication and machining yourself, for what you'd pay you could probably afford a new B-series transmission, clutch and mount kit.

-Brian Gillespie, Hasport Performance

Super-D Intake Manifold
I have a question about the Super-D (Aug. '07). In your pic you show an auto Y8 manifold. Is this just for illustration, or is this the manifold you used? I thought you couldn't use an auto manifold in a manual car. So if it is, how did you do it? I have a 90 EF that I am building a mini-me engine for. I'm using the stock block D15B2 and a Y8 head. I have both a manual Z6 manifold and an auto Y8. I would like to run the Y8 because I already know it flows better, however, I was told being auto, it wouldn't work.

-Bob Bedinghaus / Eaton, Ohio

Yup, we used an automatic manifold. As I'm sure you already know Bob but for those who don't, the difference between the auto manifold and the manual manifold is the Idle Air Control Valve (IACV). The auto uses a three wire valve and the manual uses the more common two wire. Since our Super-D was strictly a race engine and no one cared if it idled at 800 or 1,500 rpm, we just did away with the IACV.

BTW, if you are looking for the D16Y8 manifold and can only find an automatic version, it can be modified to accept the two wire IACV. The mounting bosses are cast. You'll just need to drill and tap them.

-Brian Gillespie, Hasport Performance