zep Posted February 19, 2020 Share Posted February 19, 2020 I'm trying to buy new injectors but appear to have no idea what I'm doing. I'm replacing low impedance 510cc Evo III injectors with some slightly larger volume high impedance ones, but can't figure out if I'm looking at the right thing. These are my current injectors: https://i.imgur.com/VaoUmLE.jpg From what I've read they are EV1 type. If I buy any other EV1 type, should I assume that they will be the same dimensions? When I search for EV1 injectors, I get all sorts of different looking things. Also, notice the two black seal/ring things? One butts it up against the fuel rail, and the other at the port on the manifold. Looking at other Evo injectors, I don't see any using the seal cushion at the manifold side (mine were installed by a speed shop, I assume they added them in?). Are these something I need to buy (old ones are a bit shagged)? They appear to be slightly tapered from 15mm-14mm, but it's hard to measure a squishy thing. Any help is appreciated here! Cheers Quote Link to comment Share on other sites More sharing options...
Roman Posted February 19, 2020 Share Posted February 19, 2020 What I would reccomend, is dont buy any injectors that dont come with a datasheet. Make sure you get CC rating (at a specified pressure) and deadtime/voltage chart. Personally if I was doing anything turbocharged I'd just go straight for an ID1000. They can idle great even at very low pulsedwidths, partially because they come with a great datasheet. Not too spendy especially if you consider how much fuel / tuning time you waste with slightly cheaper but garbage injectors. According to this, fits Evo 3.http://injectordynamics.com/injectors/id1000/ Usually there are just two different dimensions of top O-ring, think it's 12mm and 14mm but same size injector can use either without issues. Then at the bottom if it uses regular injector seal things, just reuse those instead of a lower O-ring. Essentially the purpose of the lower seal is to just stop a vacuum/boost leak around the injector. Some factory big-ish injectors are pretty garbage, RX7 ones are notorious for having massively differing flow rates between same injectors. So buyer beware especially second hand stuff. EDIT: I thought EV1 specified the plug type, but it looks like it is about the internal construction of the injector. https://www.rx7club.com/single-turbo-rx-7s-23/comparison-older-style-bosch-ev1-vs-newer-bosch-ev14-injectors-974696/ Quote Link to comment Share on other sites More sharing options...
zep Posted February 20, 2020 Author Share Posted February 20, 2020 Thanks. That helps. I guess my concern was that newer injectors don't seem to have that seal at the rail end (not the o-ring, you can see it in my pic). And the seal cushion thing at the manifold end, mine are perished so I need to find a replacement set. Next question then. When drilling out the rail, does the injector need to bottom out against it or will the friction of the o-ring pull the injector into a good seal with the manifold? Quote Link to comment Share on other sites More sharing options...
zep Posted February 20, 2020 Author Share Posted February 20, 2020 To add, are you saying that new injectors are way better than old ones at managing their fuel use? I recall that people used to say that you shouldn't use too large injectors, something about optimal duty cycle. Sorry, I really don't know much about this stuff! Quote Link to comment Share on other sites More sharing options...
kpr Posted February 20, 2020 Share Posted February 20, 2020 your old injectors with the seal top and bottom (not the o-ring) usually have a little bit of pressure clamped from the fuel rail to seal off nice at manifold / head end. hence a rubber thing each end. the top one isn't actually a seal. newer injectors more just rely on the o-rings. you want get the fit close as you can, but otherwise long as they aren't flopping around in there, no issues. like roman suggests if you just get some upgrade injectors for and evo. should be able to wack them straight in. Injectors are better and newer ecu's are far better at controlling them. old ecus didn't have much resolution. so at idle with big injectors, the smallest increment change on the fuel map would be either too lean or too rich. good 1000cc injectors on a decent ecu work just fine now days. also as roman says if you can get some that come with dead time values. will end up with a nicer running engine once all tuned. Quote Link to comment Share on other sites More sharing options...
zep Posted February 20, 2020 Author Share Posted February 20, 2020 1 hour ago, kpr said: Injectors are better and newer ecu's are far better at controlling them. old ecus didn't have much resolution. so at idle with big injectors, the smallest increment change on the fuel map would be either too lean or too rich. good 1000cc injectors on a decent ecu work just fine now days. I plan to continue to use my Link g3 but with g4 firmware. Not sure if this is too old in terms of what you're saying? Quote Link to comment Share on other sites More sharing options...
kpr Posted February 20, 2020 Share Posted February 20, 2020 You're limited to batch fire with G3. But are all good resolution wise, will run bigger stuff fine. its the old lem's and linkplus that struggled to run big injectors Quote Link to comment Share on other sites More sharing options...
zep Posted February 20, 2020 Author Share Posted February 20, 2020 Thanks @kpr - do you agree with roman concerning running the 1000cc injectors, even on my little 1.9 sohc 8v engine? I did a rough calculation on the injector dynamics website and at 8000rpm on 20psi it'll only be like 50% duty cycle. And @roman, those injectors look better than most others I've looked at. Better off buying the best, right? Cheers for the advice guys. Quote Link to comment Share on other sites More sharing options...
yetchh Posted February 20, 2020 Share Posted February 20, 2020 2 hours ago, kpr said: its the old lem's and linkplus that struggled to run big injectors Hah, I was literally about to ask that question.. Quote Link to comment Share on other sites More sharing options...
kpr Posted February 20, 2020 Share Posted February 20, 2020 id1000 Probably bit of an overkill. but shouldn't have any issues running them. They are at least based on a bosch injector which are cheaper. but the id's you get the deadtime data and a matched set for the extra money. have seen them run fine on smaller engines than yours. I run 980cc bosch ev14 injectors in my n/a 1600cc. on g4 link. cant really comment on how nice it idles with them because of big cams. but resolution wise, easy Quote Link to comment Share on other sites More sharing options...
yetchh Posted February 20, 2020 Share Posted February 20, 2020 I'll have to upgrade when I turbo it as it was running 95% injector duty, n/a's ok for now. Quote Link to comment Share on other sites More sharing options...
zep Posted February 20, 2020 Author Share Posted February 20, 2020 @kpr Thanks. It looks like the current version are the ID1050x. Quote Link to comment Share on other sites More sharing options...
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