Prelude DifferencesI own a '94 Prelude Si with an H22 VTEC swap. I've noticed while looking for parts that the Prelude Si and VTEC versions have some differences. I've heard that only the brakes were different (larger rotors on the VTEC model), while I also heard that the whole front strut assembly and brakes are different. Can Si components be swapped out for VTEC parts? Also, after doing some internal engine mods, can I raise the rev limiter without chipping the ECU or enabling the knock sensor?Zeb HowellJacksonville, NCdestruction_27@hotmail.com
To answer your question, we went straight to the source and picked technician Robert Young's brain at Weir Canyon Honda in Yorba Linda, Calif. First off, Young tells us that all '92-96 Preludes share the same front shock absorbers, upper and lower control arms, hubs and knuckles. However, you heard right in regards to the brakes. Your Si rotors are in fact a bit smaller than the Si VTEC's 11-plus-inch discs. The good news is that Young tells us the rotors will swap right over. The bad news is that you'll also have to shell out for the Si VTEC caliper assemblies and pads-not too bad though considering some brake changeovers require the swapping of a number of suspension components as well.
As for your second question, the answer is no. Without some form of ECU reprogramming you won't be able to raise your rev limiter. Besides, even if you could, this would pose a dangerous situation as fuel and timing requirements may not be up to snuff in that RPM range. Your best bet is to look into a reprogrammed ECU of some sort. If you'll be diving into that bottom end, replacing internals, raising compression or whatever it is you plan on doing, both fuel and ignition timing are going to need to be addressed.
Electronics Scare MeI have a '04 Civic Si with a Comptech exhaust and Injen cold air intake, and I want to turbocharge it. I'm mechanically inclined and could install the kit, but the electronics involved scare me. I intend to go with either a RevHard or Greddy kit and both include the necessary engine management, but I really don't know exactly what I need to keep the engine running safely under boost. I don't intend to modify the internals. I live in Ohio and the best octane we have is 91. Electronics scare me; please help.Mitch RaceN. Canton OHrace-mdr@sbcglobal.net
A turbo kit is only as good as what it has to offer in regards to fuel enrichment. We took a look at both the Rev Hard and GReddy kits and both are offered with everything you need to keep your engine boost-friendly, including fuel enrichment. We get the impression electronics scare you, so you may want to check out the Rev Hard kit first. The kit uses a Hondata K-Pro system in conjunction with the factory ECU to not only control the larger injectors they supply but also to take care of timing issues. The result is about the safest turbo setup you could hope for this side of fortifying your bottom end. The folks at Rev Hard tell us that the K-Pro comes pre-programmed and is a plug-and-play affair; in other words, no wiring.
The GReddy kit is a contender in its own right but prepare yourself to dive into some wiring schematics when it comes time to hook up the eManage-GReddy's own fuel enrichment solution. The GReddy kit also comes with larger injectors meaning you won't be compromising your ride's reliability. Whichever kit you decide to go with, be sure to follow all of the instructions, keep the boost levels conservative and stick with the 91 octane. We like that you're proceeding with caution. It's important to remember that Honda never intended its engines to see the kinds of cylinder pressures turbochargers exhibit so it's not the kind of thing you want to jump right into without some forethought.
F QuestionsI own a '94 Accord four-door LX and love the platform. Instead of the F22B, I have an F20A7, which was installed by the previous owner. I don't know much about this motor except for that it came in a '93 2.0i Euro-market Accord, has 9.0:1 compression, is OBD-1 and puts out 131hp.
I'd like to keep this swap since I've never seen it on a USDM Accord (something different than the simple, but effective H22 swap) and I think the rod/stroke ratio will be worth the battle (85mm x 88mm). I'd like to make it a high-revving N/A engine, not turbo, but don't know what parts would fit the block. Finally, do you think an F22B2 head swap would make things easier? I'd eventually like to autocross/track this car.Robert GardnerRobert.Gardner@aviano.af.mil
While we appreciate your desire to keep this rarified F-series under your hood, we can't help but feel that upgrading it might be quite costly. You're right to assume that the F20A7's more ideal rod/stroke ratio would be of benefit, after all, you'd be looking at a more useable upper RPM range and slower piston speeds which mean increased engine longevity, but the tradeoff might not be worth it. While you may benefit from this un-Accord-like rod ratio, it'll do you little good if you can't find the parts you need. We suspect you'll have a difficult time finding connecting rods suitable for this block so a custom set will probably be in order. As for the slugs, other F-series pistons may work, as it's unlikely that Honda strayed from the traditional F-series pin height. Without seeing the block, we're guessing the differences lie in the rods and crank. We suggest arming yourself with a calculator and some engine math to assure everything from the compression ratio to the deck height works out.
As for the head swap, the two are similar enough so you may want to just keep what you have but you also may want to consider valve size and lift prior to popping in a set of non-F20A7 pistons. Depending on the difference between the two heads, if any, custom valve reliefs may need to be machined into the piston tops.
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