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View Full Version : Best bang for the buck SR20DET injectors?



**DONOTDELETE**
12-13-2001, 02:22 PM
On injectors -

4 720cc injectors might be tricky to use - large injectors, even at very low pulsewidths, squirt quite a bit of fuel, making idling with large injectors tricky.

As far as top feed injectors, 2nd generation (87-91) RX-7 Turbo injectors are 550cc. 88 was the first year of high impedance injectors, and all '89-91 injectors are high impedance with similar injector plugs to what Nissan uses. RX-7 owners frequently swap out the stock injectors for larger ones, so they come up used quite often.

The 3rd generation RX-7 (93-95) uses side feed injectors like Nissan does - 2 550cc primary and 2 850cc secondary injectors. I'd love to know if these would fit properly in a Nissan fuel rail - those are also readily available used.

Most larger injectors are typically low impedance, which means you need to bump the resistance that the ECU sees up to drive them properly. Radio Shack sells 10 ohm resistors that do the trick *perfectly* - they are high wattage, and look like 2" long white cement blocks, for lack of a better description. 99 cents (I think) gets you 2 of 'em. Simply cut one of the wires to the injector (doesn't matter which) and put the resistor inline on the wire - problem solved.

Of course, if you wanna throw some serious fuel at the equation, I know where you can get 1600cc injectors for $90 http://www.freshalloy.com/. Lots of RX-7 guys use those for secondaries on high-horsepower cars - it's not an injector as it is a firehose...

**DONOTDELETE**
12-13-2001, 05:18 PM
<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by fc3s7:
On injectors -

4 720cc injectors might be tricky to use - large injectors, even at very low pulsewidths, squirt quite a bit of fuel, making idling with large injectors tricky.

As far as top feed injectors, 2nd generation (87-91) RX-7 Turbo injectors are 550cc. 88 was the first year of high impedance injectors, and all '89-91 injectors are high impedance with similar injector plugs to what Nissan uses. RX-7 owners frequently swap out the stock injectors for larger ones, so they come up used quite often.

The 3rd generation RX-7 (93-95) uses side feed injectors like Nissan does - 2 550cc primary and 2 850cc secondary injectors. I'd love to know if these would fit properly in a Nissan fuel rail - those are also readily available used.

Most larger injectors are typically low impedance, which means you need to bump the resistance that the ECU sees up to drive them properly. Radio Shack sells 10 ohm resistors that do the trick *perfectly* - they are high wattage, and look like 2" long white cement blocks, for lack of a better description. 99 cents (I think) gets you 2 of 'em. Simply cut one of the wires to the injector (doesn't matter which) and put the resistor inline on the wire - problem solved.

Of course, if you wanna throw some serious fuel at the equation, I know where you can get 1600cc injectors for $90 http://www.freshalloy.com/. Lots of RX-7 guys use those for secondaries on high-horsepower cars - it's not an injector as it is a firehose...<HR></BLOCKQUOTE>

Thats exactly what we did to our turbo DOHC VTEC, he had some RC injectors off a LS motor which apparently ran at a differnt impedance than what the VTEC uses, so we had to use some resistors to correct that problem. I know of some 3gen RX7 injectors I MIGHT try to use. I wonder if they would work on my car, I will try sometime next month.

jvh22a
12-13-2001, 08:53 PM
there was some talk that the supra injectors might fit... they will not work.

**DONOTDELETE**
12-14-2001, 12:08 AM
I'm looking into getting some larger injectors; maybe some 550s, are there any decent priced injectors out there or even stock ones that are side feed and 550?

Yury S Lyalko
12-14-2001, 12:12 AM
We have some 480cc injectors from the s15. Brand new.
We also have a high flow fuel rail that will allow you to use top feed injectors. You an use the ones from a supra. Finding those is easier and MUCH cheaper.
Email me if you are interested.

Other options are slim. Get SR20DET injector kits. SARD makes cheaper ones. Around $110 each. Might be a wait.


Yury Lyalko www.srswap.com (http://www.srswap.com)

**DONOTDELETE**
12-14-2001, 12:31 AM
My RC Engineering 550cc's are for sale $300. use the fuel rail yury mentioned with a Resistor pack from a junked honda motor and you have yourself a setup with bigger inejectors.

The reason for the addition of the resistor pack is that most ecus dont have high enough current capability to control low impedence injectors like the RC's.

**DONOTDELETE**
12-14-2001, 12:32 AM
I see Blitz makes a kit for the SR as well, but knowing name brands, I'm kind of iffy on price. I would rather opt for some generic ones or even some type off another car.

ADAM HUTCHINSON
12-14-2001, 12:33 AM
greaser..will your 550cc injectors fit my s13 sohc motor? i might be switching out my 310cc ones when i go to a EMS

please advise..
thanks

**DONOTDELETE**
12-14-2001, 12:39 AM
<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by ADAM HUTCHINSON:
greaser..will your 550cc injectors fit my s13 sohc motor? i might be switching out my 310cc ones when i go to a EMS

please advise..
thanks<HR></BLOCKQUOTE>
Since you have a SOHC, i'll have to check the manifold design and the top of the fuel rail. Unless you have a custom rail which IRCC you are using stock rail. I think that the injectors will drop right in. I'll ship you a Grand Am injector (GM style which is what these RC's are) for you to try as i just gave the car to charity(w/o turbo http://www.freshalloy.com/)

ADAM HUTCHINSON
12-14-2001, 12:42 AM
using stock rail...

how many clicks are on them?

will need some in feburary....or should i get even bigger ones? maybe 700cc?

**DONOTDELETE**
12-14-2001, 12:51 AM
750's is what i'm getting. I want 400 rwhp. So if you want the same, get the 700's. I have low compression which needs more fuel for a given boost and hp level.

how many clicks? i'll assume you mean miles. Well....?????&gt;&gt;&gt;&gt;10,000miles??? i have no freakin idea. Couldnt be much. remember when i was making 267rwhp? thats when i put them in and had the car tuned with the 550's. They are at 88% duty cycle at 15psi and 7,000 rpm so i'm out of fuel for 320rwhp and 12.5:1 a/f on race gas.

ADAM HUTCHINSON
12-14-2001, 12:59 AM
i know what you mean...i am runnin 4x310cc's and 2x480cc's and pushing 240rwhp with that..and have maybe another 50-70rwhp more with my fuel pressure riser then thats it...then i am out of fuel...

i was thinking about some 700cc's..or maybe
4x550cc with 2x480cc..thats like having 4x790cc injectors?

i guess i have my NOS injectors i could turn on...they are unlimited amount of fuel http://www.freshalloy.com/

Yellow4g63
12-14-2001, 01:17 AM
this place sells fuel rails for top feed conversion on SR20's http://www.ftfmotorsports.com/