I have been searching for a month for a definitive answer, or a similar setup.
VH41de (basic boltons)
Mikuni TB's(01 zx12)
Talking to my friend who's run MS3 before, he suggested microsquirt as simpler and less expensive setup(add the two needed coil drivers for wasted COP) and batch fire the banks. Then he kind of got wishy-washy last minute, and said we might want sequential for the idle tuning ect.
The car is a going to be daily driven. I've read the megamanual on Batch vs Sequential so please don't try to school me in the basics. I would just like to know if anyone has ran a batch fired ITB setup on a street car with good success. What would be say... a percentage of difference in fuel economy between the two? Is the initial start up and idle tuning more difficult with a batch fire? I realize that good streetability is somewhat an owner opinion -I don't need Cadillac smoothness, but I want to make it through the drive through for a cheeseburger occasionally without stalling or surging ect.
Aren't ITB's more delicate in the tuning process? I've almost got this motor back together and I am needing to make a decision on which one... and I am nearing the end of my budget as well. Thanks for the input
ITB Batch or sequential
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Read the manual to see if your question is answered there before posting. Many users will not reply if the answer is already available in the manual.
If your question is about troubleshooting, configuration, or tuning, you MUST include your processor type (MS-I or MS-II) and code version in your post. If your question is about PCB assembly or modifications, you must also include the main board version number (1.01, 2.2 or 3.0). For tuning/troubleshooting questions, please attached a datalog and your MSQ file to your post.
If you have questions about MS1/Extra or MS2/Extra code configuration or tuning, please post them at www.msextra.com Such questions posted here will be moved to: a temporary MSextra sub-forum, where they will be removed after 7 days
The full forum rules are here: Forum Rules, be sure to read them all regularly.
-
Teranfirbt
- MegaSquirt Newbie
- Posts: 8
- Joined: Mon Dec 12, 2005 9:31 pm
Re: ITB Batch or sequential
I've got a Toyota 3AC running CBR600 throttles on batch fire, alternating injectors in the firing order.
Tuning it with MAP was pretty much impossible. The throttles have MAP ports that are tied together, but the 3AC doesn't pull enough air at any RPM to make them useful. It idled ~32 kPa, but as soon as I opened the throttle more than 10% it shot up to atmospheric and was useless. Trying to use a vacuum manifold to get MAP signal actually made things worse, it idled ~55 kPa and went to ambient as soon as I touched the throttles.
Solution was to run Alpha-N, which is an animal in itself. Cold starts just fine with enough crank enrichment, but dies if you close the throttle. Fast idle bypass valve makes the situation worse since it's not tuned for that scenario. I pretty much have to hold the throttle open slightly until it's warm, but when it's warm it runs great. I drove it all of the way from Oregon to Texas like that, averaged 31 MPG in my '86 Tercel wagon, up from 29 with a Weber carb.
If I wasn't swapping a 4AFE into the car, I would probably make a manual fast idle cable setup, similar to an old school carb choke, that would hold the throttles open when it was warming up so I wouldn't have to work all 3 pedals at the same time.
Here's the setup:
Tuning it with MAP was pretty much impossible. The throttles have MAP ports that are tied together, but the 3AC doesn't pull enough air at any RPM to make them useful. It idled ~32 kPa, but as soon as I opened the throttle more than 10% it shot up to atmospheric and was useless. Trying to use a vacuum manifold to get MAP signal actually made things worse, it idled ~55 kPa and went to ambient as soon as I touched the throttles.
Solution was to run Alpha-N, which is an animal in itself. Cold starts just fine with enough crank enrichment, but dies if you close the throttle. Fast idle bypass valve makes the situation worse since it's not tuned for that scenario. I pretty much have to hold the throttle open slightly until it's warm, but when it's warm it runs great. I drove it all of the way from Oregon to Texas like that, averaged 31 MPG in my '86 Tercel wagon, up from 29 with a Weber carb.
If I wasn't swapping a 4AFE into the car, I would probably make a manual fast idle cable setup, similar to an old school carb choke, that would hold the throttles open when it was warming up so I wouldn't have to work all 3 pedals at the same time.
Here's the setup:
