i was just thinking the other day....why couldnt we make a simplier, less sophisticated 8 injector setup... something like this... 4 decent size injectors, then 4 pretty small secondary injectors... take the return line and run it to the secondary fuel rail and then back to the tank.... wire in a boost switch that is set to your desire.... then parrelell your injectors with, i guess you'd need to wire the boost switch to a relay to kick in and allow the secondary injectors to be in parrallel with the first set.... i think you would need to play around to find out what size injectors you would need.... you wouldnt really be able to control much unless you changed injectors..... now this was just a thought to throw out there... i dont know if it would work for a cheaper method to a sfmu, or as a safety feature using the sfmu? any suggestions or reasons for it not working....i dont know, lets just have some coffee and talk
doug

no...

Originally posted by Chamuko
no...

yeah...just no. heh

makes my head spin thinking of the things I believe you're over looking. Don't let me squelch your ingenuity though, keep thinking IMO. :thumbsup

Whats going to control those extra 4 injectors?..our ECU sure won't. Thats why people with the 8 injector setup ran an additional controller...EIC, MS, AEM etc...

Our ECU is not programmed to read data for flow of 8 injectors...theres preset calculations in our ECU that implement injector control based on several readings from various sensors...this is my understanding.


Gotta love winter

You get the exact same effect by installing larger injectors in the stock rail.

The reason we add secondary injectors and piggyback fuel controllers is to add a feature the factory ECU doesn't have- boost sensitive fuel control.

Originally posted by thedawg
boost sensitive fuel control.

mmmmmmmmm



Jon

1997 Eclipse RS
1998 Dodge Dakota Sport
12.671 @ 111.660 1.586 60' 5/28/04

www.haiokuracing.com

shaun> i'm sayin', bro!

Doug,
Actually, I think it's a pretty interesting idea. The portfueler is a similar idea with its 8 injector setup. I think it's a good brainstorm.

I suppose the problems I see with it lie with the lack of a rising rate regulator (you mentioned this would be an alternative so you didn't have to go that route). The problem is when the secondary injectors open, they'll be dumping the same amount of fuel throughout the boost range. For example: If the sec. injectors open at say, 3psi and your top boost is 14 psi, they'll deliver the same amount of fuel that whole time. It'll run pig rich at 3, and dangerously lean at 14. Without either a RRR or and electronic boost referenced injector map (ie, standalone, MS), it wouldn't run right at all. The way to correct this situation is to get an S-FMU or MS, DEFI, FAST for the secondary injectors, and at that point, you might as well not have the secondaries.

Good idea though!!

Brian

Edit: The other problem we have is that there is no return line stock. So you'd have to put one in.

this has been discussed in a slightly diferent fashion withi the past year. ECU wont control them and you cant wire to the EU in any way shape or form. Cant wire them to a switch and 12+ due to the injector not able to accept 12 constantly running through it. The injector will burn out. Search to find more info that was already posted.

Terry

Originally posted by Star Turbo Talon
this has been discussed in a slightly diferent fashion withi the past year. ECU wont control them and you cant wire to the EU in any way shape or form. Cant wire them to a switch and 12+ due to the injector not able to accept 12 constantly running through it. The injector will burn out. Search to find more info that was already posted. Terry

the turbododge people already have a solution that can;
old VW and saab cold start injectors. These ARE meant to be on continuously.

http://www.gusmahon.org/html/fuel.htm

http://www.thedodgegarage.com/turbo_extrainj.html

and a simple EIC
http://web.archive.org/web/20031206032738/www.omniturbo.com/Mopar+Pages/extra+injectors+control+detail.htm

although, this is a VERY ghettorig solution

yeah i knew that there was a problem with no rising rate or adjustment with the flow once the second injectors kicked in... i just thought as a safety factor, maybe some tiny ass injectors that only spray a little fuel at full boost just to help...i dont know, just an idea...i really want to try the "true" 8 injector setup, i just dont like the idea of 300$....i just havent had good luck with my sfmu...
doug

Originally posted by lickscissors
i really want to try the "true" 8 injector setup, i just dont like the idea of 300$

Modding cars = spending lots of money. 300 bucks aint nothing.

If you want a turbocharged car, be prepared to start a money pit.


Gotta love winter