A. Unfortunately, the ITR (and GS-R) ring gear bolt pattern is different from the one on your LS differential. This means you will not be able to simply bolt your LS ring gear onto your new ITR differential. Trying to use the ITR ring gear doesn't solve your problem either-it is not compatible with your LS pinion gear (different gear ratios). The only way to make this work is to use the ITR/GS-R ring and pinion gears together. The bad news is the pinion gear is part of the countershaft so you will have to put in some work. The conversion can be done if you have the correct parts, but it is not a simple bolt-on deal.
Q. I just turned 16 and got a '99 Civic EX. The D16Y8 engine in this Honda is fantastic, except for the fact that I can't find a company that sells all the parts needed for many things (at least they recommend I get the pieces all from the same company) like cam gears, retainers or a turbo. When looking around for parts I always see nice sets of all the pieces needed for B-series engines. I always hear of Hondas doing a bit of swapping with the engines. Instead of scraping some D-series parts together, should I just go for a swap to a B-series motor and tune that?Robby ReyesVia the Internet
A. The SOHC VTEC D16Y8 is one of the better versions of the D16. As you've already noticed, the aftermarket support for it is decent, but limited when compared to the B series engine. Don't worry so much about getting parts from the same company. What matters is finding quality parts that work together to build power. For someone who has just turned 16, funds are usually a large factor in deciding what route to take. Another consideration is how much wrenching experience you might have. Building a naturally aspirated D16 will improve performance. This is a great place to start if you don't have much experience working on cars. Bolting on an intake, exhaust, headers and cams are where most of us learned how to do things. Skipping this step and moving on to swaps and turbos is what gets a lot of the DIY crowd into trouble. It's important to do your time and learn the basics. Companies like Skunk2 (www.skunk2.com), Crower (www.crower.com), Bisimoto (www.bisimoto.com), and AEM (www.aempower.com) have a decent amount of bolt-on parts for your engine. Check out d-series.org for a wealth of information on these engines. If you're ready to go past the bolt-ons, boosting the D16 should be considered. Start saving your lunch money cause this mod will cost you some cash up front. Edelbrock and GReddy both have turbo kits for your car. You could even venture out and put your own turbo system together. Bang for your buck, turbocharging the stock D16 will probably be the best way to get to about 200 WHP. If you need more, either build the bottom end or consider swapping to a B18 and adding boost.
Q. I want to build a D16Z6 with either P29 (D16A1) or PM7 (ZC) pistons so I can bring the engine's compression to about 12.03:1. I was hoping to be able to run a Skunk2 stage one cam, but I'm not sure that there will be enough valve clearance. Am I going to have enough clearance? If not, what about using the head gasket from a D16A6, which would give me about 11.66:1 compression; would that work? If not, how low would I need to go? I plan to run a clay test either way, but it would make it much easier if I knew if something was going to work for sure before buying the parts. And one more question: If I was to run the cam but only with a lower compression ratio, what kind of difference is that going to make because of the lower compression versus a stock cam and 12:1?Wes WitbyVia the Internet