Injectors

[DarkDevilMMM]

The 86-88 RX7 Turbo are using Denso 550cc low imped injectors (tan top) which on paper should fit a DSM perfectly, is there a reason why we should not use them? The only problem I see is that it's a single spray pattern instead of dual spray pattern like the 2G DSM injectors(black top). Are there any other problems you guys heard of that one should not use on their DSM? Thanks.

 

[MX4]

I read that they basically dump fuel rather than any type of atomization of the fuel. In saying that I ran a set in my GVR4 many years back. I never logged it with those injectors so cant give any feedback on that front, other to say that they will work. Whether it is better to go with normal injectors I'm not sure.

 

[DynastyLCD]

sounds like they would drop right in. OP, why wouldn't you rather go with Evo injectors, rated at 560cc?

my argument for this, is that newer injectors such as the Evo ones, are made with better technology, spray better and more consistent patterns, and can be easily dropped into any GVR4/DSM with minimal mods.

with the amount of Evo owners modding their cars nowadays, im sure you could get a set of their stock injectors for really cheap.

 

[DarkDevilMMM]

My concern with the Evo 560cc is because of their dead time, they have weird dead time that makes them not "drop in" ready, unless you have some ways to modify the numbers in the ECU or have standalones which doesn't care about what the ECU wants at all. That's why I would prefer the older Evo ones that are 510cc (yellow top) with dual spray patterns, but those are quite expensive comparing to any larger injectors out there.

 

[ktmrider]

Hey DD on a parallel topic I have some 510 yellows available if interested, PM me.

 

[DarkDevilMMM]

So nobody else is going to school me on injectors and their designs? I am pretty sure someone somewhere has something more to say /ubbthreads/images/graemlins/laugh.gif come on, don't be shy, I am counting on you all.

 

[TomN]

People were using the old turbo rx7 injectors 15 years ago. They work fine. You don't really hear about them anymore cause of all the new injectors available these days along with fuel management systems that make it easier to use larger injectors. Back in the day using more than a 550 injector on a 1g or gvr4 required the use of a AFC and the genius AlBlaha MAF just to get it to idle right.

 

[beaner]

Quoting DarkDevilMMM:
My concern with the Evo 560cc is because of their dead time, they have weird dead time that makes them not "drop in" ready, unless you have some ways to modify the numbers in the ECU or have standalones which doesn't care about what the ECU wants at all.


I've never heard of that. Dead time is based on many variables, so each car will be a little different. Compared to any other injector out there evo560s are excellent. They react a little quicker than the stock injectors. I had my dead time zero'd out with them on dsmlink. Before link I had them in with nothing more than a 2g maf and the car was fine, actually drove way better compared to my old 450s.

 

[DarkDevilMMM]

Ok, I know I am not going to be the best person to explain this, I suck at explaining stuff, but as I understand it, according to this page, Evo8 560cc injector doesn't seems to follow the "pattern" of the lag time of the rest of the "potential" denso injectors. For example, by comparing the chart, it has almost the same exact lag time as a 3kgtvr4 360cc injectors. So that means, if I have a stock 3kgtvr4 ECU, it is using x amount of time opening and closing a 360cc injector, but if you replace it with the evo8 560cc, which uses the same exact time as the 360cc to fully open and close, it's spraying out the full amount of 560cc of fuel instead of 360cc, that is, they are spraying way more then it should. Therefore, from the ECU point of view, they act like a way larger injector then they "should be".

Yes it doesn't matter when you turn up the boost or giving it more air when driving, but at idle or vacuum, there is no way of "giving" it more air, so at that time, you are basically wasting fuel by a LOT, and it's really hard to "dial it in" correctly with just basic piggy back electronics.

So in your case it works out fine is because, first, you started out with 450cc to 560cc, the difference is way less then from 360cc to 560cc. Second, that's the reason why it can be corrected easily by simply using a 2G MAF. So that just makes up the difference, you can correct it more by using a hacked MAF.

I am sure I am using the wrong terminologies here and there, please correct me if needed. Oh and yeah, I am using the injectors on a 3kgtvr4, that's why I really want to stay away from using the evo8 560cc.