Want to run 8, 550cc injectors

[Tsi_forever]

What do you guys think of running 8 rc 550cc injectors to equal 1100cc. I was thinking of using a dual output fpr and welding in 4 injector bungs, and remap the eprom to run 1100cc at 180ms dead time.

 

[king_of_HTX]

Why not just buy a set of 1000cc injectors?

 

[b00stedtalon2]

Why not just buy a set of 1000cc injectors?

Yeah what he said.

 

[flashburn02]

I think the idea here is a less condensed spray. I like the idea actually. Better air fuel mixing less fuel management needed over the 1000s. I like it!

 

[PieEyedPiper]

I'd think it would need MORE fuel management.
i.e. an safc could never cope with that I don't think.

 

[MelloEclipse]

that's like running 8 cylinders....when a good set of 4 would do the job

 

[Talesin]

Sounds overly complicated and pointless. Like the guy who wanted to hook up two 1G MAS units on a funky ass Y-pipe intake, instead of just getting a damn 2G MAS or MAF-T unit.

Get 1000cc, or even 1600cc injectors and DSMLink. It'll idle like stock and drive like it too on the low end, after you set it up properly. Add two or three ounces of acetone to each tank of gas, and you'll get much better atomization. If that's not enough, raise your fuel pressure and tune to compensate with Link. You'll have all of the mixing (or better) of a pointless, over-complicated 8 injector setup, with a tenth the hassle.


PS - Fill in your car profile. It'll help people suggest upgrade paths based on your model year, rather than randomly guessing at what you might or might not have.

 

[RedTurboEclipse]

Run 4 1000cc or higher and DSMLink. Call it a day, why make simple things difficult to be different.

 

[freshlane]

AMS does it with their drag car (http://www.amsperformance.com/amsdragevo.php). It is a drag car though.

 

[FORMONTOYA]

Sounds overly complicated and pointless. Like the guy who wanted to hook up two 1G MAS units on a funky ass Y-pipe intake, instead of just getting a damn 2G MAS or MAF-T unit.

Get 1000cc, or even 1600cc injectors and DSMLink. It'll idle like stock and drive like it too on the low end, after you set it up properly. Add two or three ounces of acetone to each tank of gas, and you'll get much better atomization. If that's not enough, raise your fuel pressure and tune to compensate with Link. You'll have all of the mixing (or better) of a pointless, over-complicated 8 injector setup, with a tenth the hassle.


PS - Fill in your car profile. It'll help people suggest upgrade paths based on your model year, rather than randomly guessing at what you might or might not have.

Correct...and good call!

AMS does it with their drag car (http://www.amsperformance.com/amsdragevo.php). It is a drag car though.

Just because someone "jumped off a bridge", does that mean it's the way to go?

 

[freshlane]

Just because someone "jumped off a bridge", does that mean it's the way to go?

I never said he should do it. I was stating the fact because I didn't want people on this forum to think it was a original idea without any research behind it.

 

[red_devil]

Couldnt you set it up like an rx7?

 

[tkelly27]

There are only two reasons I can think of to run two sets of injectors in a street car.

1st. One set can't do both low and high load conditions. It may be the case that you can't get 1600cc's to idle on your setup, but 1000cc's aren't flowing enough for your top end. Solution; run 600cc's at idle, and turn on an extra set of 1000's when the 600's alone can't meet the flow demand. That requires computer hardware that can integrate injectors like that. I think that is how RX-7's do it, and it's only useful if it is having problems at idle.

2nd. You're too cheap to get a real set of injectors. No different than a cold start injector or bumping the fuel pressure up, just another trick to play to get more fuel for cheap. There was a guy on another turbo forum who upgraded from 36pph injectors to 52pph (yeah yeah, non-metric, sorry). He put the 36pph on a boost switch with a RRR in the IC pipe right before the TB. Not saying it's a good idea, but he did have the potential for a ton of fuel delivery with minimal work.

If your goal is 1000cc's, it's most likely the second case, which is a lot of work and a lot of $$ into a set of injectors to get something that you may or may not be able to tune properly. Not trying to dump on someones new idea, but you've got to factor in resistance, placement, putting in new injector bungs and a fuel rail, to emulate something you can just go out and buy for less than the cost of the two set's of 550cc ones. It might be of use if you had 2 sets of 450cc's you got for free.

Racing is a different story. Top fuel cars have something like 5 injectors per cylinder, pre-supercharger, post supercharger, a pair in the intake, and a direct injection setup in the cylinder. I think that's the way it is...

 

[SFRacingGST]

Pruven Performance put a dual injector setup into an evo 9. It was making around 800 HP I think. Theresa a forum I was reading in the evo tuners webpage. However, Pruven totally screw the kid over and he took it to AMS to finish it. In order to do this you need a custom rail and/or manifold that accepts 8 injectors. You need a stand alone program with a wiring harness that allows 8 injectors and the capability to tune each one individually (forgot the program he was running). The reason it was done in dual stages was to make it a street car. Instead of running 1600 injectors and have it not very street able, they ran something like 850's and 650's. The car's low throttle and idle ran off the 650's (idles like stock), however the bigger injectors came on in sequence to the turbo spooling. Very complex system, very hard to tune for and dial in the injectors. Unless you have lots of money to blow, than I would definitely just stick with large injectors and dsm lnk. If you want to blow a few grand on a fuel setup just to reach a goal of 1000cc, than in my opinion it is just a waste of money. Maybe if more people wanted to go this route a company like AMS would make a kit for sale to the public. Pruven makes a kit, however they only sell it to you if you’re getting it installed there because its so complex. (by the way, I wouldn’t go there from personal experience for an oil change and a free car wash, let alone anything else)

 

[tkelly27]

If you wanted to to this REALLY badly and wanted it to be totally trick, you could use a 29c EPROM with a pair of maps. One for 550cc's and one for 1100cc's. When you hit X boost (or airflow) level it would switch over to the 1100cc map and the same switch would allow the pulses from the computer to go to all 8 injectors.

It would still not be as cheap, easy to tune, or look as clean as getting a set of 4 larger injectors and tuning it. You would certainly be unique, and it would be totally your design and implementation, and for some people that's all that matters.

 

[Tsi_forever]

There are only two reasons I can think of to run two sets of injectors in a street car.

1st. One set can't do both low and high load conditions. It may be the case that you can't get 1600cc's to idle on your setup, but 1000cc's aren't flowing enough for your top end. Solution; run 600cc's at idle, and turn on an extra set of 1000's when the 600's alone can't meet the flow demand. That requires computer hardware that can integrate injectors like that. I think that is how RX-7's do it, and it's only useful if it is having problems at idle.

2nd. You're too cheap to get a real set of injectors. No different than a cold start injector or bumping the fuel pressure up, just another trick to play to get more fuel for cheap. There was a guy on another turbo forum who upgraded from 36pph injectors to 52pph (yeah yeah, non-metric, sorry). He put the 36pph on a boost switch with a RRR in the IC pipe right before the TB. Not saying it's a good idea, but he did have the potential for a ton of fuel delivery with minimal work.

If your goal is 1000cc's, it's most likely the second case, which is a lot of work and a lot of $$ into a set of injectors to get something that you may or may not be able to tune properly. Not trying to dump on someones new idea, but you've got to factor in resistance, placement, putting in new injector bungs and a fuel rail, to emulate something you can just go out and buy for less than the cost of the two set's of 550cc ones. It might be of use if you had 2 sets of 450cc's you got for free.

Racing is a different story. Top fuel cars have something like 5 injectors per cylinder, pre-supercharger, post supercharger, a pair in the intake, and a direct injection setup in the cylinder. I think that's the way it is...

It's a kinda of #2, I own another set of 550's and I have everything at my disposal to fabricate what I need.

If I were to build a progressive injection system the secondary fuel rails would be spraying alcohol. I toyed with this idea as well, possibly using megasquirt as fuel only to control the direct alcohol injection. Tuning would probably still be a pain. I know i know, most of you are thinking I'm making this more complicated, but I like thinking out of the box.

 

[tkelly27]

By the time you're done with MS and fabricating the injector bosses and all of that, you could have had one of these
http://www.alcohol-injection.com/dsm-progressive-kit-p-70.html
and been done in and tuning afternoon.

I like the foreward thinking, but adding a stand alone computer to run an extra set of injectors while keeping the stock computer to run the other is a complicated design. If you could make a MS, I'm sure you could learn how to have two sets in part time batch fire. One bank of injectors is kept off after a certain boost level. Which would be how it was suggested you run it before.

Another system I've heard of is to boost reference the alcohol container so that with each psi of boost it goes up 1psi on the regulator and 1psi at the inlet of the fuel pump. Fuel pumps work on pressure differentials it has to create, not pure psi, so that shouldn't be a problem.

If you're planning on going that route, that is, where you're computer seamlessly switches over to gas+alcohol injection, I'd make sure you have a system to drop the boost dramatically if you've run out of alky.

For the record, I think alky injection is silly, and would rather just go full on alky or E-85 all the time. I don't like the idea of the only thing keeping my engine from blowing up is a 1 gallon fuel cell under the hood. That's just my opinion though.

 

[Dream On]

Sell both sets of 550's and get some larger ones.