Why do I REALLY need larger injectors than 450s for a Big 16G?

[4gfun]

Just don't want to waste my money, and I am very curious about this since this is my second DSM.

Both of my DSM's were/are alleged 12 second cars. I noticed that both of the previous owners ran 450 cc injectors on them.

This all seems to be too much of a coincidence for me, it really does.


In addition, I have read that Bushur had run 120 mph trap speeds on his DSM but turned up the Fuel Pressure.


If I want to run 22 psi on the street on pump gas, is it REALLY a MUST that I upgrade my injectors?

Thank you for your time.

 

[4gfun]

New EVO's, 16g type turbo, 560cc injectors = OEM reliability. Seems that they are on to something huh?

hmmmmm seems so!

 

[steve]

Except that don't run that 16G at 22psi.

People are getting rid of 650/680cc injectors all the time as they look to upgrade for E85 or bigger turbos.

I wouldn't look at anything smaller.

 

[flinguist]

Well all, I am back in the game. Lol, it isn't what you think either. Well I did wreck my engine, but it was because the timing belt flew off and bent all the valves!

I know this is an old thread...but I see that you have been replying to it for half the time since I left.

I have a 91 GVR4 now . The question is still on topic too. This time, I am not going to skimp out on injectors .

Based on that, do you guys have any idea what the optimal injector size is for a Big 16g if I plan on running high boost on 93/94 Octane and never plan on going with a larger turbo?

That's right, my GVR4 has a big 16g too.

I plan on pushing boost as high as some of you have on the 16g e.g. 22-23 psi on pump gas and I want to make sure that the 550s can handle it.

I won't be limited by the SAFC this time either. This GVR4 came with an EEPROM ECU and Ostrich Emulator.

Thank you for your thoughts! Everything in this post seems to indicate thta 550s will be enough, but some time has passed and I wasnt to see what you all think and if I understand correctly.

My EVOIII 16G was too much for 550's at 25 psi. IDC was over 90%. I'd go bigger to provide a safety margin.

 

[4gfun]

Alrighty, I am ready to conclude here. I have been beating this to death for a long time here (not that this is a bad thing IMHO since it allowed me to reach a logical deduction).

I think I will go with 650s just in case I have a difficult time tuning with and/or understanding the Ostrich myself, I will have somewhat of a fallback with the SAFC.

I believe it is a timeless debate on the 650s due to timing issues with the SAFC, but I would bet that I wouldn't be too far off with the SAFC as a fallback.

Again my goals are this:

Sort of rediculous boost on 93/94 octane pump fuel e.g. 20-25 psi based upon what I find when tuning.

I do not plan to ever go beyond a Big 16 turbo in size. I do not plan to go meth or use race gas.

If E85 hits my area it will be hard to say no.

So really this is all that remains:

1) Will 650s be enough?

2) What am I looking for in used or new 650s? (I don't want to just go buy a set of used 650s and not know what I am doing)

3) Will 650s still be useful if E85 ever comes to town? (I figure that they will be even more useful so please correct me if I am wrong)

Thanks again for your patience!

 

[steve]

Even 680s will be too small if you run E85.
baseinjectordata [ECMTuning - wiki]

Once you have the ostrich the SAFC will be useless.

 

[4gfun]

Even 680s will be too small if you run E85.
baseinjectordata [ECMTuning - wiki]

Once you have the ostrich the SAFC will be useless.

Gotcha on the E85, but what do you mean the SAFC will be useless?

Thanks

 

[steve]

what do you mean the SAFC will be useless?

Because it's so much easier to directly change the ECU parameters rather than flip back and forth between the SAFC menus and on the SAFC the injector correction and timing are dependent rather than independent valiables. The only thing you give up is being able to twist the dial in realtime. Once you have the ostrich in the car your SAFC is going to be zero'ed out so it's just something extra to go wrong.

Don't try to do more than one thing at a time when editing the ECU until you gain experience. Start with just the injector parameters for global (size) and deadtime (latency). Once you have them nailed down you can play with the fuel map to adjust your AFR or the timing map for your advance.

 

[4gfun]

Because it's so much easier to directly change the ECU parameters rather than flip back and forth between the SAFC menus and on the SAFC the injector correction and timing are dependent rather than independent valiables. The only thing you give up is being able to twist the dial in realtime. Once you have the ostrich in the car your SAFC is going to be zero'ed out so it's just something extra to go wrong.

Don't try to do more than one thing at a time when editing the ECU until you gain experience. Start with just the injector parameters for global (size) and deadtime (latency). Once you have them nailed down you can play with the fuel map to adjust your AFR or the timing map for your advance.

I agree...to the degree that it will never touch this car!

Only other thought is back on the injectors. I am having a tough time finding 650s or 680s used for a good price. It seems like 550s and 580s are dirt cheap. (I wonder why). Since I plan on getting (or even buying back the old AFPR that I mentioned years ago in this thread and will be getting a 255 lph pump) why can't I just crank up the afpr and use some 550s or 580s?

Never mind...650's it is...haggling with the seller who is probably reading this lool!