Alex GL-10 Posted December 1, 2006 Share Posted December 1, 2006 What are the differences in the two. I know the MAF sensor changed and I read somewhere that pre 87' had gen 1 heads. What are other differences? Link to comment Share on other sites More sharing options...
jeffast Posted December 1, 2006 Share Posted December 1, 2006 87.5 xt turbo's got the spider intake and like 30 more hp, a little off topic but it's what i know for certian Link to comment Share on other sites More sharing options...
calebz Posted December 1, 2006 Share Posted December 1, 2006 87.5 xt turbo's got the spider intake and like 30 more hp, a little off topic but it's what i know for certian Don't think they got any extra power. Definitely not 30.. Maybe 3-4 because of better flow, but otherwise everything is the same as the non spider motors (injectors, fuel pump, boost levels and such) Link to comment Share on other sites More sharing options...
Caboobaroo Posted December 1, 2006 Share Posted December 1, 2006 no real power differences (maybe like 1-2 hp), MAF is different, disty, and a few bolt on stuff. Yes, pre '87 had gen 1 heads for sure, most of them up to '88 did when they started using gen 2 heads and gen 3 heads, are mainly current NOS and replacements for cars under warranty back in the day (like '90). Cams were also different I believe and there's something else I think is different but I cannot remember. Blocks are all the same, heads are the same, cam cases and covers are the same, intakes I believe are the same and so is the exhaust and the turbo as well. Link to comment Share on other sites More sharing options...
Alex GL-10 Posted December 1, 2006 Author Share Posted December 1, 2006 I knew the MAF sensors were different, but what makes them different? I'm assuming that most parts are interchangable between to two? Link to comment Share on other sites More sharing options...
GeneralDisorder Posted December 1, 2006 Share Posted December 1, 2006 I knew the MAF sensors were different, but what makes them different? I'm assuming that most parts are interchangable between to two? The MAF's are completely different (as in different theory of operation - one uses a hot wire, and the other a flapper door), as are the distributors, so the ECU, and the parts of the wireing harness used for those components are too. Most other parts probably would interchange fine. GD Link to comment Share on other sites More sharing options...
RenaissanceMan Posted December 1, 2006 Share Posted December 1, 2006 PRE 87 injection was gang fire, where as post 87 injection with the optical distributor is sequential injection. Better for fuel economy and emissions fo sho... (pretty sure, but I'll have to recheck my wiring diagrams to make sure) -Mike Link to comment Share on other sites More sharing options...
mikeshoup Posted December 1, 2006 Share Posted December 1, 2006 PRE 87 injection was gang fire, where as post 87 injection with the optical distributor is sequential injection. Nope. Sequential injection is impossible without a cam position sensor. No MPFI EAs have sequential injection. Its all batch fired. Link to comment Share on other sites More sharing options...
mikeshoup Posted December 1, 2006 Share Posted December 1, 2006 I got curious about this, so I went and compared the 86 FSM to the 88 FSM. The differences I noticed: MAF - Old system is flapper, new is hot-wire Distributor - Old system is hall effect w/ vac advance, new is optical, timing controlled by ECU Knock Sensor - Old system has two wire, new has one TPS - Old system TPS just has an Idle switch, and fully open switch. New has an extra potentiometer to determine throttle position WGDS - Old system the wastegate is a direct hookup. New has a solenoid that slightly controls boost. I think its an altitude compensation thing. Pressure Switch - Old system has one and uses it as a fuel cutoff. New one doesn't, and uses the MAF signal to determine fuel cutoff. Everything else seemed to look like it worked the same. SO, theoretically one could swap those parts on to their 85-86 and the ECU, and you could gain a small amount. Link to comment Share on other sites More sharing options...
Alex GL-10 Posted December 1, 2006 Author Share Posted December 1, 2006 I got curious about this, so I went and compared the 86 FSM to the 88 FSM. The differences I noticed: MAF - Old system is flapper, new is hot-wire Distributor - Old system is hall effect w/ vac advance, new is optical, timing controlled by ECU Knock Sensor - Old system has two wire, new has one TPS - Old system TPS just has an Idle switch, and fully open switch. New has an extra potentiometer to determine throttle position WGDS - Old system the wastegate is a direct hookup. New has a solenoid that slightly controls boost. I think its an altitude compensation thing. Pressure Switch - Old system has one and uses it as a fuel cutoff. New one doesn't, and uses the MAF signal to determine fuel cutoff. Everything else seemed to look like it worked the same. SO, theoretically one could swap those parts on to their 85-86 and the ECU, and you could gain a small amount. Thats what I was looking at. The biggest thing would be cuting the connecters for the ECU off the newer wire harness and putting them on the older wire harness because they don't plug into the same places. Link to comment Share on other sites More sharing options...
mikeshoup Posted December 1, 2006 Share Posted December 1, 2006 Might be easier to just swap engine wiring harnesses... I actually thought about doing this to the EA81T with how rare they are and difficult to find parts. The EA81T intake has almost nearly an identical sensor system as the pre-87 EA82T. Link to comment Share on other sites More sharing options...
nkx Posted December 1, 2006 Share Posted December 1, 2006 Cams were also different I believe by different do you mean better, or just different due to different dimensions and/or tolerances in the head and cam tower? Link to comment Share on other sites More sharing options...
mikeshoup Posted December 1, 2006 Share Posted December 1, 2006 Actually, the cams are different. I had posted somewhere before the different duration. The later cams are probably actually better. The early cams are the same as the carb cams. Though I think the difference is minimal. Link to comment Share on other sites More sharing options...
joostvdw Posted December 1, 2006 Share Posted December 1, 2006 you said the pre87 models had a direct waste gate control and 87+ had a boost solinoid? well, I have a '88 XT with spider and hotwire, but without a boost solinoid? how can this be? perhaps because it a euro? (yet another difference to add to the list) Link to comment Share on other sites More sharing options...
calebz Posted December 1, 2006 Share Posted December 1, 2006 you said the pre87 models had a direct waste gate control and 87+ had a boost solinoid? well, I have a '88 XT with spider and hotwire, but without a boost solinoid? how can this be? perhaps because it a euro? (yet another difference to add to the list) Correct.. the euro model EA82 runs on a different set of rules than USDM. IIRC, the EDM models came out at 136hp Link to comment Share on other sites More sharing options...
PoorManzImpreza Posted December 2, 2006 Share Posted December 2, 2006 ...and a factory oil cooler (P/Ns 21315AA001, 21319AA001, 21317AA001, 806959010, 806923020, 45711GA021[sedan/wagon/3d], 45711GA030[XT], hmm this list is longer than I thought.. lol I should just scan the part page)....and a different crank shaft P/N 12201AA030 Link to comment Share on other sites More sharing options...
Alex GL-10 Posted December 7, 2006 Author Share Posted December 7, 2006 Can you tell any difference in power between the two? (pre 87' and after 87') Does one take power mods better then the other? Link to comment Share on other sites More sharing options...
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