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Injector sizing

Posted: Sun Mar 19, 2017 12:34 am
by type85
So I'm currently running generic Bosch copy 30lb injectors: 0-280-150-756
These are on my 20v N/A 2.6L running E85, after the latest intake and exhaust work, I'm @ 18.5 on my main scaler and 1.1 @ full throttle on the map. I'm seeing close to 19ms inj. intervals, I was told not to exceed 20ms?
I'm barely seeing 8.5 A/F at full throttle above 4k rpm.

Should I go larger on my injectors? I was thinking of going to 36lb. genuine Bosch: 0280156023 http://www.ebay.com/itm/Bosch-Fuel-Injector-for-Saab-9-3-9-5-2-0-2-3-Turbo-Lifetime-Warranty-0280156023-/200983765746?hash=item2ecb90e2f2:g:-hAAAOSw-4BXasqN&vxp=mtr
That's a %20 increase, should I go larger? I don't think I'll get much more out of this engine, an aftermarket header is in the works, but that won't be a huge increase in power
I will also occasionally run gas, so I want enough resolution to still run clean at idle, right now, E85 @ idle the injectors are running at ~4ms.
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Re: Injector sizing

Posted: Sun Mar 19, 2017 10:40 pm
by ChrisAudi80
When you say 8.5:1 AF, is that is gas AFR or Ethanol AFR? If you use lambda, it would be easier.

Re: Injector sizing

Posted: Sun Mar 19, 2017 10:44 pm
by type85
ChrisAudi80 wrote:When you say 8.5:1 AF, is that is gas AFR or Ethanol AFR? If you use lambda, it would be easier.


This is A/F for E85
8.5:1 A/F is about .87-.88 lambda

Re: Injector sizing

Posted: Mon Mar 20, 2017 8:57 pm
by ChrisAudi80
In that case, sure why not? If you are at 4ms at idle, you could go slightly larger. Just make sure you get the injector data.

Re: Injector sizing

Posted: Mon Mar 20, 2017 9:34 pm
by type85
ChrisAudi80 wrote:In that case, sure why not? If you are at 4ms at idle, you could go slightly larger. Just make sure you get the injector data.


I went ahead and bought genuine Bosch green giants (got a good deal with an Amazon giftcard and creditcard points!), so I'm going from 320cc's to 420cc's

Re: Injector sizing

Posted: Mon Mar 20, 2017 10:17 pm
by loxxrider
You really can't hurt anything going with larger injectors. You could go with some modern 1200s and still have the same or probably better idle quality. The only trade-off is price. Anyway, looks like you have a solution. :)

Re: Injector sizing

Posted: Mon Mar 20, 2017 10:38 pm
by type85
loxxrider wrote:You really can't hurt anything going with larger injectors. You could go with some modern 1200s and still have the same or probably better idle quality. The only trade-off is price. Anyway, looks like you have a solution. :)


Thanks!