20g injectors

[toomey200]

could i run 550cc injectors with a 20g turbo and a walbro 255 fuel pump and not have to worry about fuel cut problems at high rpms with an AFC?

 

[brute]

With a 255, you'd need an adjustable fuel pressure regulator. And you could use 550cc's, but you'd have to keep the boost down.

 

[toomey200]

ok if i used the 190 fuel pump would i still need the pressure regulator? and also with the 550s would i be able to run between 18-20psi without the fuel cut out probs? thanks

 

[The_EE]

You could run about 17psi on 550's. You would need 720's to run 20psi +. Trust me on this.

 

[toomey200]

my friend has 660s and runs 20-25 psi with out any probs... do u think i should jus invest in the 720s either way?

 

[andymoraitis]

If you plan on controlling your injectors with something like DSM Link or an EPROM ECU with a Keydiver Chip, go as large as you like. If you'll be running the AFC, you'd be better of with a max of 650's. People have tuned 720's on an AFC, but the timing curves get way out of whack from the airflow correction and you won't be able to run as much boost on pump gas as a result. Even with 650's, you'll be chasing your tail trying to get the right balance to keep knock away.

Hope that helps,

Andy

 

[awdrst]

I ran 24 psi on my 20g with 650's on pump gas. My IDC's were right around 83%.

 

[andymoraitis]

I ran 24 psi on my 20g with 650's on pump gas. My IDC's were right around 83%.

I hear you. I'm running the same boost on a 50 trim and pump and haven't maxed out my 650's either.

 

[toomey200]

ok cool so you guys would recomend the 650s and which fuel pump? if i used the walbro 190 fuel pump would i still need a fuel pressure reg?

 

[andymoraitis]

I think if you're gong to invest in a proper fuel setup, you should pick up a 255 HP with an Aeromotive FPR Kit from Import Evolution (get a liquid filled gauge to go with it). The 190 will do well without an AFPR, but it would be wiser to have all of your fuel needs met now instead of having to go back and buy more parts later. Besides, fuel pressure is a valuable tuning tool and it makes dialing in a good tune even easier.

Do it once and do it right!

Good luck,

Andy

 

[nightspeed87]

If you plan on controlling your injectors with something like DSM Link or an EPROM ECU with a Keydiver Chip, go as large as you like. If you'll be running the AFC, you'd be better of with a max of 650's. People have tuned 720's on an AFC, but the timing curves get way out of whack from the airflow correction and you won't be able to run as much boost on pump gas as a result. Even with 650's, you'll be chasing your tail trying to get the right balance to keep knock away.

Hope that helps,

Andy

I would like some more info on that post....
as far as running the safc and the biggest inj. set up you say you
wouldnt go bigger than 650scc perhaps?

 

[andymoraitis]

That's correct. The AFC works by fooling the ECU into thinking that airflow into the motor has been reduced. This is required to make larger injectors run like stock. When the ECU perceives less airflow, even if it's being tricked to do so, it runs more timing. As a result, it's hard to tune high boost and high timing, especially on pump gas. This creates a tail chase where you'll need to keep playing with airflow to find a happy medium. The larger the injector in cc's, the more correction is needed and the more timing is raised. There's only so much correction value programmed into the unit so while you theoretically can try running 720's or 750's, you can't optimally subtract enough fuel to make it work properly. In addition, the timing curves can become insane thereby creating a cycle of constantly trying to balance boost and timing.

To sum it up, using an AFC to tune is like trying to hammer a nail with a tree stump. It'll work, but it's not the optimal solution. Irrespective of whether people have gone fast on them or not, I still find them to be inferior pieces of garbage when used as a solitary tuning tool and I'm being generous in my description.

Let me know if that makes sense,

Andy

 

[nightspeed87]

To sum it up, using an AFC to tune is like trying to hammer a nail with a tree stump.

.....

Yea I get you... So basically your not playing with big boy powerlevels untill youve gone dsm link... Ive got a 91 eprom in my car but never considered getting dsmlink because it seems soo expensive and sounds harder and more complicated to play with, and my goals are never no more than 350whp... So do you have dsmlink or safc?
I want to run the biggest inj set up possible, and according to you I should be happy with 650s and no bigger right? Well how does it work if I hacked my mass or run a 2g mass because mines is hacked, and I plan on a 2g mas in the near future.

 

[andymoraitis]

I play with big boy power levels and I don't use Link or an AFC. I have a custom Keydiver chip with special A/F and timing maps that eliminate the need for either. The great thing for me is that if I wanted to change to a GT35R and run 1000cc injectors, it can be done with a simple chip swap.

For your goals, you'd do OK with an AFC, but it would be better to have a chipped ECU to at least control the injectors so that you didn't need to rely on the AFC to do that for you and contribute to the timing problems I described above. You could also run any injector size you wanted and not have a problem. You could then take some fuel out with the AFC and since the amount of airflow adjustment is much less, you'll have an easier time tuning.

I've probably done consultations with 20-30 site members who wanted to eliminate their AFC's and use a custom tune in the chip. All of them said it was the best thing they ever did and that their cars were noticeably faster. I've often been criticized for having such a well assembled setup with very simple tuning, but I prefer it that way. All I use as reference to tune is a look at my knock readings, spark plugs and fuel pressure.

However, DSM Link is fantastic for what it does.

Since I haven't used an AFC on a 1G that switched to a 2G MAS, I can't offer anything there. You'll see much better airflow before running into overrun, but I can't say much more than that since I don't have firsthand knowledge. If you were doing that with a chipped ECU, it's a simple thing to add to the code and it's completely turnkey.

 

[nightspeed87]

thats great... Youve been a lot of help... A local dsmer out here in tampa has access to all the chip burning stuff ( Im pretty sure he was talking about the same thing your talking about now ) therefore when I get to that point I think i may just get the chip burned also and do similar like you, and just rely on the logger for knock I guess.... It would save money from buying dsmlink or an afc , well at least for now...
I think i want to get it set up so that I can run some good 650s and the 2g mas and still be able to compensate for whatever a 14b/16g could push efficiently ( and thats should be enough to reach my 350whp goals after other extensive mods in the head and etc. possibly ) Havent settled on which turbo I want to use yet, but may end up just settling with a 16g since my demands arent too drastic. Since you say you can use afc and the chip together maybe Ill just get even BIGGER injectors and use the chip to help them run normal, so therefore if one day I ever did exceed my goals now ill already be set up to go into the 400+ hp realm I suppose huh?....

One quick question, do you have to keep getting the chip reset/ or re newed everytime you change your set up.. ( i.e. raise boost/ air sensor style/ turbo ...? )

 

[andymoraitis]

The only people I'd recommend for chip tuning are either Jeff and Nate from DSM Chips or our own wiseman Steve. These guys are intimate with the ECU and you get what you pay for. This is one area where you really don't want to skimp on a good setup. As a matter of fact, you wouldn't even need the AFC if you used custom A/F and timing maps. You could sell it and recover the cost of the chip easily and still have plenty left over to buy a race chip in case you wanted to try high octane. Also, the stock boost gauge will be able to read knock, so although you can keep the logger, you'd now be able to see up to 15 counts in real time instead of waiting to pull data at the end of the run.

Chip re-burns are only needed for changes to injectors, timing, A/F and things like that. If you were simply changing boost, the chip maintains the same parameters and doesn't need to be tweaked. You'd need a new one for an MAS switch, but upgrades are cheap (20.00).

To give you an idea, I'm running the same chip that I was running with my Big 16G even though I now have a 50 trim. I run a conservative A/F and very low timing (12 degrees max advance) so that I can get away with big boost on pump gas. If I put in an FP Green or a 20G, I'd keep the same chip. The only reason I'd need to change is if I switched to larger injectors.

Glad this stuff makes sense. Damn we pretty much trashed this thread...

 

[nightspeed87]

yea pretty much but I think everyone would be interested in hearing what youve got to say .... So I think youve convinced me and I want to go the chip route...
Would it be pointless or a waste of money to get the chip done for stock turbo and injectors, or should I just wait till I get the injectors of choice and the 2g mas have them ran with the chip...? ( And how much does all the chip burning cost? )

Also, the stock boost gauge will be able to read knock, so although you can keep the logger, you'd now be able to see up to 15 counts in real time instead of waiting to pull data at the end of the run.

( I dont have a stock boost gauge anymore because I have those reverse glow gauges in my car because I was sick of the stock orangeish oldschool red because it didnt match my car. But I didnt order the ones with the stock boost gauge since I figured I didnt need to look at it since I have a real boost gauge.. )

But are you suggesting that the actual stock boost gauge turns into a knock counter?
Thats bugged out if so, since you can see the knock as it happens... And all this is done with the chip huh... I must say im impressed, but your saying to only have it done through one of these guys huh? The guy i was talking to sounds real confident about the chip burning he does and runs them on his car... Maybe ill just investigate into it further and see if he does good work like the guys you referred.

 

[andymoraitis]

I'd wait. For all of the information you could possibly want to know, have a look at http://www.dsmchips.com and have a good read. You can e-mail questions about your boost gauge functions to Jeff or Nate and they'll be able to help, but yes it becomes a knock sensor if it's programmed that way.

 

[nightspeed87]

ok thanks I appreciate it...


So according to the link you gave I will need the stage 3 for everything im going for... ( was still cheap )
I know a guy with a honda who i think used this chip service because his check engine light comes on when he shifts at 8k as it was programmed that way...
So you have to have dsmlink to do these chips though right? ( Which I have a 91 eprom ecu )
And you dont have to have your car down for a couple weeks in sending your ecu to them do you?
Or do you just tell them what you want and your set up and thats it, and they ship you the chip?
For instance after I get my 2g mass and injectors I just tell them my inj. size, and everything else I have on my set up
and they ship me the chip already perfected for my set up even without afc? On the page they recommended having a afpr ( which I will have ) and afc controller ( which I might not at the time).... You say you dont have one or need it because you can customize your own timing and fuel maps. There isnt any danger in doing that since you cant fix nothing, or are they that good that they can do it all for you on the chip.
If so there able to fine tune your ecus afr values just with the chip so that id never have to waste money at the dyno tuning? )

 

[andymoraitis]

RJ,

Let me try to get to these one at a time:

1. DSM Link and these chips are a different ball of wax. You can have one without the other, but both require an EPROM ECU
2. If custom A/F and timing tables are used, the AFC is no longer needed, but can be kept if you ever want to lean the car out on race gas.
3. ECU turnaround is usually one week or so including socketing and the chip. You can certainly send your ECU in via 2-3 day and have Jeff send it back via 2-3 day by paying a bit extra for the shipping costs.
4. I'll do your chip settings for you during a phone consultation, PM them to you and then you can e-mail them to Jeff.
5.Timing and A/F maps are fixed in the chip. Unlike DSM Link you can't adjust them, but they're similar to Link except for the ability to change them.
6. If you wanted to maximize your power, you could still do a custom chip., add race gas, turn up the boost and use the AFC for little corrections. This is if you wanted a dyno tune.

It all depends on what your goals are. My car will never see a dyno so I don't plan on doing any of those things. I just put a good tune on it and run the snot out of it.

Whew, now I'm tired.