Tech Support May 2009 - Rearend - Super Street Magazine

Here's where we act like we know something technical about cars. Feel free to ask us about your technical troubles. Write us at tech@superstreetonline.com or Super Street c/o Tech Support, 6420 Wilshire Blvd., Los Angeles, CA 90048. Feel free to include a picture of your project or tech problem.

Question Of The Month
Q I am putting a D16Z6 into my '92 Civic hatchback. It originally had a D15B1 non-VTEC and I am wondering if the motor will mount up to the D15 transmission and ECU without any problems or if I need to do something to make it work right.
Corey Ferrill
Via the Internet

A Well Corey where do we begin. To start off with, if you truly have a '92 it shouldn't have a D15B1 as that is an EF engine. If for whatever reason, someone decided to swap that into your car before you owned it you might have some concerns already as to wiring. If by the off chance you made and error reading or typing, and you have a CX or DX EG hatch it should have a D15B7 in it. As far as the transmission is concerned - you're golden, everything bolts right up. The ECU will still operate the car, but not properly as it is not intended for a VTEC engine and thus has no circuitry to engage VTEC, which will cause a MIL (check engine light) and poor driveability. The correct ECU to operate the D16Z6 is a P28. Unfortunately, in the late '90s- early '00s, these ECUs were highly sought after for aftermarket swap purposes and consequently can be harder to find and rather expensive. Another option is to have the stock P06 ECU (assuming your car has the D15B7) modified and chipped to mimic the maps of a P28. The last thing you'll need to do is run two extra wires, one for VTEC oil pressure and one for the VTEC solenoid to pin into the ECU. There are plenty of write ups and pin-outs available online. It might sound tough now, but it's really not that difficult. Best of luck.

Tech Support
Q First off, I want to say I have been a big fan of your magazine for close to a decade now and this is my first time writing in. My question is a little different. I've never been a big fan of nitrous. My philosophy is this, if your engine is built to support enough HP that the nitrous could provide, then there are better ways of getting that HP more consistently and reliably. Such as turning up the boost. However, I realize that nitrous has its uses. So, being a huge fan of Time Attack, I am curious as to why you never see any cars that have nitrous for the straightaway section of the tracks? I have a few reasons in mind, but I would like to know the true reason. Thanks for your time.
Joey Dickerson
Via the Internet

A To answer your question simply - there are cars that compete in Time Attack with nitrous, lots of them, you just aren't looking hard enough. Nitrous has many benefits, namely you can make lots of power for relatively low cost. Sure you could boost an application, but a decent turbo setup will run you roughly $4000 by the time you have everything necessary. Nitrous is nearly 1/10th that and can yield excellent gains and, contrary to popular opinion, is very reliable when a car is properly tuned for it. At the end of the day it's up to you as far as your build path.

Q While I would love to tell you something you haven't heard, I'm just not that creative - so I'll just say that I love your mag and for you to keep up the great work. My question isn't so much a tech question per se, but I'm sure there are some readers out there that have asked the same question at one time or another, especially with old school restorations and rare wheels becoming so popular. I just acquired a set of Advan RGs and while I would love to say that they are perfect, they aren't. I bought them with some curb rashes, a couple chips here or there, but all in all in really good shape. I'd like to know where I might have these beauties restored back to their original glory. Can you guys help?Bill GreerSummerville, SC

A Great find with a set of RGs, Bill. A good wheel repair shop is hard to find and you're right, it is important to have them restored to their original condition. While we recommend researching shops that might be local to wherever you're living, we do know of a few Los Angeles-based wheel repair shops that can do the job. Call around and get a few quotes, but here are the ones we'd trust: Tru Wheel in North Hollywood, CA (www.truwheel.com); American Briteworks in Garden Grove, CA (abwchrome@att.net); and RB Wheels (www.rbwheels.com). Good luck!

Q I have a '91 240SX with 210k miles and an RB20. I want to put in TEIN coilovers and a 2-way LSD, but people told me not to because the chassis is too old to do some drifting and others are saying there's nothing wrong with that. I don't know who to believe or what, but should I keep investing on parts or just buy a newer 240SX with less mileage?John MendezRiverside, CA

A If some of the world's top drifters are still using an "old" chassis like the S13, then what does that tell you? Selling your current 240 for a newer chassis wouldn't benefit you in any way really because any car you'd buy would probably need what yours needs now anyway: a set of fresh bushings. Keep doing what you're doing with your car; it sounds like it's almost drift ready with a RB20 and will be even better with the coilovers and limited slip differential.

Q First, I would like to say I love your mag! I have been getting your mag since about '02 and have loved every issue. I love the reader's rides section. Anyway, I have just bought a 1987 Toyota Supra Turbo with the 7M-GTE, but no transmission. I was thinking this might be a good time to upgrade the motor, however I don't know which one would best suit my needs for a fast reliable motor, the 1JZ-GTE or the 2JZ-GTE. I am looking for around 4-500 hp. I also want decent support for the motor. Any help would be greatly appreciated. Oh and keep up the great work.Angela DescoteauxVia the Internet

A The 7M-GTE is actually a very good engine, minus the stock headgasket. If you look back at our April issue of this year, you'll see a black MKII Supra with very built 7M-GTE. There's more than enough aftermarket support to build that motor reliably. A great place to start would be checking out www.supraforums.com and www.supramania.com. But if you had the budget for a 1JZ or even 2JZ swap, it would be of course a newer better option. But do you really need something beyond 400hp? We say just find a transmission and rebuild your engine. There's nothing like having the factory engine and not having to modify or fabricate things to make an engine fit. The money you save, you could put towards a turbo kit, and easily beat out any stock JZ.

Q I just bought my first car, a 1991 Mazda Miata, but it was recently in a fight with a deer and the deer won. So, $4,900 later, I got a sexy red convertible with carbon-fiber hood, and upgraded audio. Not exactly cover-worthy but I like it. I bought a lower bumper but the shop said they couldn't figure how to put it on so can you explain to me exactly how to install it? Also I would like a really nice suspension system but I have no clue, which is best for my car. Any help would be great.Alex BrookeVia the Internet

A Front lips or lower bumpers simply screw on from underneath. Any bodyshop should be more than able to put that on for you. If they didn't do it, they probably just didn't want to. We'd suggest finding a different shop. It is for a ('90-97) Miata and not a ('99+) one right? As for suspension, the 949 Racing spec TEIN coilovers are gaining a lot of popularity with Miata tuners. Check out www.949racing.com for more info. If that's too high-end for you, you might want to try some Bilstein HD struts with Eibach springs. That's a cheap and very effective option.