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Is aux fuel the next logical step for more power?

OP
TalkToTheFiST
Messages
436
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Location
Jackson, MO, USA
Thread Starter #21
Late to the party, but thought I'd offer some perspective. I have the Stratified 4-port on the S280. Nearing the end of the tuning process on E45.

The good part about the 4-port is that you are cleaning the valves with the spray . . . something that is useful with direct injection.

But but but . . . tuning has been a PITA. Dizzy sends you an ECU tune and then the separate fuel map for the aux fuel controller. Problem is, the 4-port seems to swing the AFR wildly with small changes . . . requiring multiple revisions of the aux fuel map alone before you can even consider getting the next ECU tune revision.

The aux fuel map is not complicated . . . it simply uses tables based on MAP vacuum against RPM. We have fallen into a pattern where he sends me the ECU tune, and I adjust the fuel map. That way, I can make multiple revisions of the aux fuel in a short time based on AFR in the logs and not get bogged down for a month going back and forth with him. I just set the 4-port table to where I believe it will be a little rich, then I adjust down until I get to where the AFR is hovering around the magic 11.7-12.2 for most of the RPM range.

Once I see good AFR, I send him the logs for input. Seems to be working so far. The latest tune is at 31 lbs of boost with good AFR. Will probably hold there, or even go back a tune, to be sure I'm haven't exceeded my risk tolerance for the block.
Valueable info and much appreciated. It actually reinforces my choice. At first i was all for aux fuel bc i liked the higher ceiling but the more i read, the more i didn't like the lack of simplicity, overcomplication can have it's own issues alltogether. And im still not quite finished with my e30 tune, then i can start on fuel mods.

I ended up buying the Bosch injectors and i will get from those what i can and be happy as it's just a daily. And my first project car at that, i will have plenty of others to go balls to the wall, this one i want to learn on with minimal issues and step it up as i go. I see myself getting another FiST down the road and making more bold choices but for my first (and one with my carseats), im going with simplicity. And it's not like 320+whp is a joke.
 


Messages
195
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174
Location
WA, USA
#22
Late to the party, but thought I'd offer some perspective. I have the Stratified 4-port on the S280. Nearing the end of the tuning process on E45.

The good part about the 4-port is that you are cleaning the valves with the spray . . . something that is useful with direct injection.

But but but . . . tuning has been a PITA. Dizzy sends you an ECU tune and then the separate fuel map for the aux fuel controller. Problem is, the 4-port seems to swing the AFR wildly with small changes . . . requiring multiple revisions of the aux fuel map alone before you can even consider getting the next ECU tune revision.

The aux fuel map is not complicated . . . it simply uses tables based on MAP vacuum against RPM. We have fallen into a pattern where he sends me the ECU tune, and I adjust the fuel map. That way, I can make multiple revisions of the aux fuel in a short time based on AFR in the logs and not get bogged down for a month going back and forth with him. I just set the 4-port table to where I believe it will be a little rich, then I adjust down until I get to where the AFR is hovering around the magic 11.7-12.2 for most of the RPM range.

Once I see good AFR, I send him the logs for input. Seems to be working so far. The latest tune is at 31 lbs of boost with good AFR. Will probably hold there, or even go back a tune, to be sure I'm haven't exceeded my risk tolerance for the block.
Oh GOD is tuning a PITA. 🫣
 


Matt32536

Member
Active Duty U.S. Air Force
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11
Location
Crestview Florida
#23
Late to the party, but thought I'd offer some perspective. I have the Stratified 4-port on the S280. Nearing the end of the tuning process on E45.

The good part about the 4-port is that you are cleaning the valves with the spray . . . something that is useful with direct injection.

But but but . . . tuning has been a PITA. Dizzy sends you an ECU tune and then the separate fuel map for the aux fuel controller. Problem is, the 4-port seems to swing the AFR wildly with small changes . . . requiring multiple revisions of the aux fuel map alone before you can even consider getting the next ECU tune revision.

The aux fuel map is not complicated . . . it simply uses tables based on MAP vacuum against RPM. We have fallen into a pattern where he sends me the ECU tune, and I adjust the fuel map. That way, I can make multiple revisions of the aux fuel in a short time based on AFR in the logs and not get bogged down for a month going back and forth with him. I just set the 4-port table to where I believe it will be a little rich, then I adjust down until I get to where the AFR is hovering around the magic 11.7-12.2 for most of the RPM range.

Once I see good AFR, I send him the logs for input. Seems to be working so far. The latest tune is at 31 lbs of boost with good AFR. Will probably hold there, or even go back a tune, to be sure I'm haven't exceeded my risk tolerance for the block.
He makes a good point about the 4 port and the fact that aux fuel is cleaning the valves. I recently did my own walnut blast and what a PITA that was. I was at 104,000 miles and those valves were nasty. After doing the blast my car runs better and mpg's are up

But of course if you plan on going WMI, then go the HPFP and injectors route.


Sent from my SM-S908U using Tapatalk
 


OP
TalkToTheFiST
Messages
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Location
Jackson, MO, USA
Thread Starter #24
Just an update, things are moving along. Got my injectors waiting in a boxa and today got the base tune needed and waiting for next wednesday for injector installation. Going 93 octane first then will add an e85 mix with the new fuel limit, e40/e50, whatever Jason@Dizzy recommends.
 


OP
TalkToTheFiST
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Location
Jackson, MO, USA
Thread Starter #25
Well today i had my Bosch injectors installed and i can only say one thing, FiST ignition coils are a pain in the ass. Shop called after the injectors were installed but he said the car kept stalling at idle, we both assumed it was bc the new tune hadn't been installed yet. So i get there and load up the tune from the AP, start the car and yep, misfire on #1. That's why it was stalling. I knew that sound from several months ago when the same thing happened and i drove it 9 miles with a #2 misfire the whole way. So my shop guy readjusted each coil, i started it up and voila, no misfire. All seems well.

2 blocks later on the way home, i get a high load misfire, which i also had at a different time a couple months ago. Runs good till you gas it at about 20psi then it bogs down with a misfire, problem is this type won't pop a CEL so you won't know which freaking cylinder it is. I still had my OEM coils saved from the first debacle (which were replaced by crap Napa coils), which may or may not be faulty, so i swapped them in one at a time just to see whap happens. Turns out cylinder 2 was the misfire, not sure if the cheap Napa coil was bad or just misaligned again but all misfires are gone and 27psi is all good.

One thing i noticed, inside the coils there is the wire and it can get pushed to the side and makes alignment almost impossible. I used a screwdriver to bend it back to center and it fitted much easier. I don't know if anybody else has these problems but my god these coils seem tempermental. Long story short injectors are in and now i can get my data logs back to Jason and get the tunes rolling. Will update as i go for anybody interested in this route. FWIW im doing a 93 tune first, then will see how far they can push an ethanol blend.
 


OP
TalkToTheFiST
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Location
Jackson, MO, USA
Thread Starter #27
At 27lbs, you’re likely at the end of the 93 tune. He’ll probably transition you to the E blend soon.
Roger that, Jason even said he'd use the old 93 map he'd already made me a few months ago as the base for the injector tune, im guessing he just wants to make sure AFR is working properly in the logs. The only reason i got this tune was in case im somewhere i can't get E85 and i'll have to jump back to a 93 tune, i needed that tune to include the new injectors.
 


Messages
83
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48
Location
Northern Virginia
#29
About a month into having just the upgraded DI injectors. Zero complaints, car definitely makes more power (probably 50whp more), and runs great. We did reach the limit of the HPFP around 340whp though. Waiting on pumps to be back in stock.
Did you dyno it to come up with that number (340)?

I ask only because my Accessport reads much lower than I believe I’m running ….
 


OP
TalkToTheFiST
Messages
436
Likes
208
Location
Jackson, MO, USA
Thread Starter #30
About a month into having just the upgraded DI injectors. Zero complaints, car definitely makes more power (probably 50whp more), and runs great. We did reach the limit of the HPFP around 340whp though. Waiting on pumps to be back in stock.
Good to hear, im not sure when im gonna want to drop $1400 for the pump and i have spent a LOT this year on mods and another $300 this week on speakers. And i don't track it or anything so 340 for trolling Civics on the road is plenty. I think tonight i might get my logs done so i can hurry and get to the ethanol tune for these injectors, that's gonna be the fun part.
 


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