Dynoed The SR -Need Injectors-

[compression]

I got my Datsun 510 (S13 redtop, S15 turbo, AEM EMS) on the dyno for the first time last week. It made 225HP and 230ft-lb at 5k RPM on 11.5 psi of boost.THe car had a few problems, at about 5250 RPM the the dyno chart starts to drop and get wavy. THen from 6400-7000 RPM it was making 30HP and bogging bad, then came back up to about 180HP from 7k to redline(7500). I logged some data during the runs, and went back and noticed that the injectors were running 100% duty cycle for a while up past 5000 rpm, they even got up to %105 at one point. I am pretty sure that is the main problem, I'm still using the 370's.So I will try it again when I finally get around to caughing up the change for the 550's (unless someone wants to donate a set for my cause, anyone? hello?)I think she had much more in her, just not enough fuel. The HP curve coming up to the 5000RPM point was climbing like crazy.By the way, I was running 11.5:1 AFR numbers.

[gawath]

I have some drop in sidefeed 740cc Fuel injectors for the stock sr20det or ka24de fuel rail on ebay. They can support more horsepower than the 370cc that you have right now. Check them out and bid. http://cgi.ebay.com/ebaymotors...%3AIT

[Nismo_Freak]

We will have the 740's and 555's in stock tomorrow.

Pricing is around $468 shipped or so for brand new Nismo injectors.

Call us at: 1-866-SPL-PART Email us: [email protected]

We take credit cards and paypal, and you have the benefit from buying from a reputable company.

[msaskin]

740's are too big for your the power you're making. The IDC's will drop too low, which generally means less than ideal spray pattern, yadda yadda.

I'd say just order the 550's (as you are prepared to do) from one of the vendors, or get a top-feed rail from jgycustoms and enjoy $60/each injectors instead of $115+ each

~matt

[ibzbro]

i have a set of slighty used nismo 555. give me an email. [email protected]

[240SXer]

740's are too big for your the power you're making. The IDC's will drop too low, which generally means less than ideal spray pattern, yadda yadda.

I'd say just order the 550's (as you are prepared to do) from one of the vendors, or get a top-feed rail from jgycustoms and enjoy $60/each injectors instead of $115+ each

~matt

Wouldnt the pulse just be lower? Couldnt he just tune it with higher fuel pressure to keep the spray good? I don't know much about it. I've got a GT2540R on stock injectors so i'm going to be going to 740ccs. I'm thinking more along the lines of 320whp at 17psi or so.. I think 740s are overkill if you're only going to keep that S15 turbo though, but it'll give you more potential.

[msaskin]

Wouldnt the pulse just be lower? Couldnt he just tune it with higher fuel pressure to keep the spray good? I don't know much about it. I've got a GT2540R on stock injectors so i'm going to be going to 740ccs. I'm thinking more along the lines of 320whp at 17psi or so.. I think 740s are overkill if you're only going to keep that S15 turbo though, but it'll give you more potential.

The pulsewidth for the larger injectors will be shorter, and IDC is a calculation based off of injector pulsewidth.

I don't think bumping up the base fuel pressure would be that good of an idea. Generally fuel injectors are rated (and designed to operate) at a certain fuel pressure and IDC. I know most companies (such as RC) do their tests at 43psi static pressure and 80% IDC iirc. At higher/lower pressures and IDC's the spray pattern can begin to get less than ideal.

This is all theory though. In real world applications, I highly doubt if the spray pattern difference is even noticeable outside of a lab environment.

For a "lower powered" car, it's of no real consequence. Obviously if you're building some 200+hp/cylinder monster, then you're going to want to start paying more attention to the theory stuff, but at this point in the game, it's nothing more than a mental exercise for everyone

~matt

[ca18det_boy]

We will have the 740's and 555's in stock tomorrow.

Pricing is around $468 shipped or so for brand new Nismo injectors.

Call us at: 1-866-SPL-PART Email us: [email protected]

We take credit cards and paypal, and you have the benefit from buying from a reputable company.

/\ /\ /\ /\ /\ /\ WOOT WOOT thats a good price!!!!