Limited Slip Differntial - Question It June 2013 - Import Tuner Magazine

Got a burning question or simply need some advice with problems you’ve encountered while wrenching on your current/future projects? Ask our automotive guru Eric Hsu anything—literally, he’s going to answer every single question, as long as it’s automotive related.

Got a tech question? Send it to questionit@importtuner.com

Limited-Slip Differential

I own a ’97 Nissan Maxima with an automatic transmission that serves as my daily driver. For the most part, the car is pretty much stock as I have owned it for only five months. I don’t plan to race the car, however to enhance my daily traveling experience, occasional spirited driving, and deal with unfavorable climatic condition, I’d like a transmission with a limited-slip differential. I can’t recall if Nissan ever offered a locking differential (VLSD) for the fourth-gen Maxima in an automatic. If not, what other Nissan options can I explore? Just to be thorough, are there aftermarket options?
-Tim, Philadelphia, PA

There was a factory viscous LSD available for automatic transmission Maximas. Looking in my ’96 factory Nissan service manual (yes, I own a fourth-gen Maxima), it appears that the transaxle code for an automatic transmission with the viscous LSD is “RE4F04V”. This can be found on the aluminum plate that is riveted to the firewall of your Maxima. Near the bottom of the plate will be the transaxle model number. To clarify, a viscous-type LSD does not ever fully lock. It will transfer power to the wheel that is not spinning however. There are no clutch-type or helical-type LSDs available for the fourth-gen Maxima that I am aware of. I called the guys over at OS Giken, which makes some of the best limited-slip differentials on the market, and they were not aware of any either. The viscous LSD units are probably still available from your local Nissan dealership, but they probably aren’t cheap. To install it won’t be cheap either since the transmission needs to be opened up to replace it.

Dilemmas

I own a ’12 Scion tC and recently installed a Flowmaster axle-back exhaust system. The exhaust sounds great, offers more power, and improves mpg! But before buying it, I talked to the dealership to see if installing the exhaust would void my warranty. To make a long story short, they said there wouldn’t be a problem if I installed it myself. Now I want to install an aftermarket intake system but the same dealership claims that I can only install a TRD cold air by an authorized dealership to prevent voiding any warranties. I honestly think the TRD unit costs too much for what it is, albeit, not knowing how well it will work. I was opting to install a K&N drop-in filter, but heard that oil elements could damage the MAF sensor. I recall a while back, Import Tuner dyno tested a dry filter and it delivered good power gains. Would you recommend an OEM-approved TRD filter, oil element drop-in filter, or dry element intake filter?
-Barry Brogan, Garden Grove, CA

Since an engine breathes through an air filter, the dealership could probably make that call by claiming that the quality of filtering may not have been sufficient and could void the warranty should there be an issue. However, the quick fix is simply to keep all of your stock parts. In the very unlikely event that there’s an issue, you simply reinstall the factory intake system. Now I’m not telling you that’s what you should do. I’m just telling that you that is what you could do. The reality is that it is very unlikely that a high-quality intake system like a K&N unit would cause any kind of failure if installed correctly.

If you don’t want to deal with any of that, then consider running a TRD intake system as a cheap insurance policy. Even if the cost is another $100, you can save thousands by maintaining your factory vehicle warranty. Isn’t it worth it?

Mazda 3 NA Build

I own a ’12 Mazda 3. I want to build a strong NA engine with plenty of power and balanced handling. The car currently has all the basic bolt-ons, which include a Corksport exhaust, K&N intake, James Barone engine mounts, and sway bar. I want to eventually build the bottom end, install an aggressive cam, and find a decent header. For a more powerful NA build, what are some other upgrades that can be performed or will these future upgrades I mentioned suffice? Also, after all these upgrades, if possible can I make this a high-rev engine successfully?
-Antonio Sanchez, San Antonio, Texas

If your budget allows, you’ll also want to look into porting the cylinder head, a high-flow intake plenum, and a larger throttle body. While it isn’t an easy modification, some people have made the Cosworth intake plenum for the second-gen Duratec-powered Ford Focus fit the Mazda 3. While this isn’t a simple bolt-on, the large volume and optimized runners really make the MZR/Duratec engine shine. The one thing you did not mention is ECU tuning. None of the parts you’re talking about will matter if you cannot optimize the ECU mapping. There are a few shops out there doing ECU reflashing, but you’ll need to find one that can do custom reflashing since your modifications would be all custom.

Boosted Stanza

I’ve been plotting over a rare project that hardly anyone has ever done. I am working on a ’89 Nissan Stanza GXE with a CA20E. My plan is for a high-horsepower engine with a JDM CA18DET. I was looking at turning a RWD CA18DET into a FWD because there are hardly any FWD CA18DET’s around these days. The parts include a water/methanol injection kit; AEM EMS stand-alone; 750cc injectors; 255-lph fuel pump; Tomei 272 duration camshafts, adjustable cam gears, solid lifters; FR Motorsports valvespring kit, coil packs; HKS BOV; ARP head studs; Cometic head gasket; and a GT2871RS turbo with a bottom-mounted turbo manifold. What type of clutch and flywheel kit do you recommend, and which motor mount kit would you suggest that could withstand the torque from a CA20DET? What intercooler kit would fit onto a FWD CA18DET, and where can I source a manual rack-and-pinion kit for a ’89 Stanza?
-Wesley Kisena, via importtuner.com

Since the ’89 Stanza isn’t a popular car to modify and neither is the CA20 engine, try contacting the guys over at Clutch Masters for a solution. If there isn’t something off the shelf already, they can probably whip something up that will work well. There will be no intercooler kit from another application that will fit your Stanza. The intercooler system will need to be custom fabricated. Unless Nissan made a manual rack for an ’89 Stanza, chances are you aren’t going to find one either. Once again, with custom fabrication anything can be done, but it will be expensive. This sounds like a very odd build. Sometimes you have to wonder why people don’t build ’89 Stanzas, but good luck.

Wheel Fitment Problems

I own a ’93 Nissan 240SX hatchback with Megan Racing Track Series coilovers with Swift Springs and Megan Racing rear adjustable control arms and rear toe arms. The wheel setup currently used is 17x9.5 Rota Grids with BFG g-Force Sport Comp 2 245/45-17 on all four corners. The car looks good but the wheels/tires stick outside of my fenders. I have been asking around and no one wants to roll and pull my fenders, which is understandable as 2 inches is a lot to pull but when I asked the body shop about Origin Lab over-fenders they estimated around $2,500 in labor so I tried to find a cheaper alternative and decided I actually like the 240Z ZG-style fender flares. I asked the body shop if there was a cheaper alternative, and they said it would cost more than fitting the Origin fenders. I am not trying to build a show car but simply trying to build a car that can be driven hard and if I get in a fender bender I wont have a complete breakdown. I am 18 years old and work part time as a bus boy in Santa Cruz, CA. The tuning scene isn’t very big around here. If there are any suggestions for ideas or body shops over the hill in San Jose let me know.
-Joel, via importtuner.com

There are plenty of cheap options to get a large front wheel to tuck on an S13. Lucky for you, there’s a whole barrage of fake Japanese M-Sport front fenders that come +20mm (little over ¾ inch) wider than stock. I’ve seen these on the web for as cheap as $100 a pair. The next thing to do would initiate plenty of negative camber to the alignment and possibly a 40-series tire to make the tire tuck under the fender. While this seems to be the trend today, it’s hardly the right way to setup a car. Running a properly sized wheel and tire combo (e.g. 17x8.5) with the larger fenders and a proper alignment would be the correct way to do it.

But if you must fit your giant 17x9.5 wheels in the front, then you may not be left with any choice other than the old-school type of fender flare. There are cheapie fiberglass 240Z ZG-style flares made to the contour of S13 fenders, but they aren’t large enough to cover your 2 inches of extra wide wheel either. Perhaps a combination of these ZG flares and a ton of negative camber might get the job done for you. Doing a quick search on eBay, I found some of these ZG-style flares for only $175. Go to Home Depot, buy yourself a rivet gun for $15 and you can rivet them on yourself. How’s that for cheap?