Gimpy's ITB's

[gimpy]

This is the project.A small block Chevy(I know, another cast iron push rod)I started with a '98 L98 block,bored .030 over & stroked to 383 cu. in.(6.3 liter up from 5.7) am using a high torque GM 383 cam with 9.5/1 comp. ratio. Ran in on a Qjet carb.(as ridden in by Fred on his epic 1st tour of the US) All this in a fairly good '77 Corvette body,driving a 700r4 trans. with 3.55 ratio rear axle(posi.)



After a good result of a Mega Squirt project on a '90 Mazda pickup with a F2T engine I decided to add a fuel injection project to the beast.I purchased a tuned port manifold base for the Vortec heads(also done while Fred was on his epic 1st US tour) & cut the runner tubes off the the cast base plates,added 1.75 mandrel bent 90 degree tubes to those, and machined up base plates for throttle bodies.





Then I made 4 2 barrel ITB's





Also fabbed linkage to balance pairs to each other and side to side.Also machined up air cleaner bases, and tops.








Also note that for ign. I used LS1 coils for a CNP settup.To supply fuel I fabbed up a surge tank that hangs below the stock tank at a slight angle to feed any air back to the main tank .







I may need to add a second low pressure pump to insure constant fuel supply until the main is empty, but so far this seems to work well.
Now to operate this pile of billet & cast I built a MS3 with all the bells & DIYauto tune harnesses . Currently is running and partly tuned (well enough to drive but not as good as it can do).Am setup on wasted spark,batch injected as I don't have the CAS sorted out yet.I've got a Ford VR cam sensor mounted on a Chevy disty. base,with a 50/50 lobe on the shaft.No pics of this yet.
I've been following FreeEMS while this work has progressed, and got really excited when the PUMA 1 was brought out so I got Fred to hook me up



I've been a bit busy soldering up harnesses so I've not found BOM's for the Puma yet but am going to start pushing on that.
Thanks for looking,thoughts & comments welcome.

Gimpy

[jharvey]

Nice ride, I'm assuming it's High Z. Have you chosen a case, or starting making one?

[jharvey]

Hmmm, ITB's This board is probably not of any real importance in this case, but figured I'd post it. https://github.com/jharvey/MultiMAP

I think your V8 is larger enough / ect, that it won't really get out of balance at idle. However, I guess it could, so if you end up having trouble with a rough idle, you might want to think about that board.

[Fred]

Gimpy, make sure the trigger that you use has at least 4 valid events on the crank shaft, or 8 on the distributor, if so, we can sample your y connected map sensor in a timed fashion and produce a smooth result (same is possible on 4 cyls with half the input count). It would be better if it had more, though.

Given you have the CNC/machining skills you do, you could cut an optical disk to my design, and I could write you a special decoder for it, this would be dubbed the FreeEMS decoder and would give the optimum in performance for any engine it was installed upon. If you're interested we can work together on the disk design and I can write the code while you cut the disk. The common optical CAS units, which I'm CERTAIN you could adapt onto some sort of cam speed drive come from most mitsi and mazda units, however the LT1 series have another suitable setup that you could use too.

Once you get the Puma setup with code and signals and are ready to run, it will fire up on pure map signal and work ok like that, however for proper WOT driving it will need a secondary table based on TPS (alpha N) and you'll need to blend the two tunes somehow. We can do that empirically when you are ready and after the map only tune is good.

Also, if you want more of your handy work in NZ, one day, you can make me some sweet custom ITBs for my secret fetish car, the air cooled beetle :-) I want to build an epic EFI electronic ignition beetle engine one day, and it'd be more than happy to have your work on it, even if I have to pay for it :-)

Post vid(s) of it running on dirty old MS! Is it really ms3? or is it ms2/v3? just curious.

Fred.

[gimpy]

Gimpy, make sure the trigger that you use has at least 4 valid events on the crank shaft, or 8 on the distributor, if so, we can sample your y connected map sensor in a timed fashion and produce a smooth result (same is possible on 4 cyls with half the input count). It would be better if it had more, though.

I'm using a 36-1 wheel on the crank,with a Ford ( ) VR sender ,I tested while it was still carbed ,with a EDIS 8 & no control it ran @ a solid 10 degrees advance.

Given you have the CNC/machining skills you do, you could cut an optical disk to my design, and I could write you a special decoder for it, this would be dubbed the FreeEMS decoder and would give the optimum in performance for any engine it was installed upon. If you're interested we can work together on the disk design and I can write the code while you cut the disk. The common optical CAS units, which I'm CERTAIN you could adapt onto some sort of cam speed drive come from most mitsi and mazda units, however the LT1 series have another suitable setup that you could use too.

Give me a count & I'll make chips.I've heard that the GM optical is troublesome, but have no experience.I'll look for a Mitsi/Maz. unit.

Once you get the Puma setup with code and signals and are ready to run, it will fire up on pure map signal and work ok like that, however for proper WOT driving it will need a secondary table based on TPS (alpha N) and you'll need to blend the two tunes somehow. We can do that empirically when you are ready and after the map only tune is good.

Also, if you want more of your handy work in NZ, one day, you can make me some sweet custom ITBs for my secret fetish car, the air cooled beetle I want to build an epic EFI electronic ignition beetle engine one day, and it'd be more than happy to have your work on it, even if I have to pay for it

I'd be insulted if you insist on paying,would love to ITB a VW boxer.

Post vid(s) of it running on dirty old MS! Is it really ms3? or is it ms2/v3? just curious.

Yes is really a MS3,with a MS3x board,& white dau. bd.Is the MS3X bd. also called beta?

Gimpy

[gimpy]

Hmmm, ITB's This board is probably not of any real importance in this case, but figured I'd post it. https://github.com/jharvey/MultiMAP

I think your V8 is larger enough / ect, that it won't really get out of balance at idle. However, I guess it could, so if you end up having trouble with a rough idle, you might want to think about that board.

Actually, first fire up the idle was terrible(added a quarter of in. to a stress crack in the drivers side fender[mud guard to the NZ])after much goofing with balance,I made a "Unisyn" & discovered that one throttle shaft had been cut with the flats out of alignment by a degree or so.A new shaft fixed this.It is a whole lot easier to balance then an under 1 liter, but balance is still very critical.Before balance the mani vac. gauge tried to beat the stop pins out of itself,but carries a fairly solid 10 inches of HG now (at idle) but vanishes as soon as it gets any throttle.Has made tuning a bear!!
Thanks for the MultiMap I'll take a peak.
Gimpy

[Fred]

Actually, first fire up the idle was terrible(added a quarter of in. to a stress crack in the drivers side fender[mud guard to the NZ])after much goofing with balance,I made a "Unisyn" & discovered that one throttle shaft had been cut with the flats out of alignment by a degree or so.A new shaft fixed this.It is a whole lot easier to balance then an under 1 liter, but balance is still very critical.Before balance the mani vac. gauge tried to beat the stop pins out of itself,but carries a fairly solid 10 inches of HG now (at idle) but vanishes as soon as it gets any throttle.Has made tuning a bear!!

For the idle balance, you could add some tubes to share the flow across, this will help with minor differences. I think 4age's have this from factory by way of a factory vacuum manifold that runs across all of them for brake booster use. Obviously at larger flows you'll need it to be correct or very close, though.

Multi map, if it contains circuits to select map for you, will make life better for sure.

MS3 *must* have blended alphan/map mode, use it, if you want the car running nice... :-)

As for mercury, what is that in kPa?

Fred.

[Fred]

I'm using a 36-1 wheel on the crank,with a Ford ( :o ) VR sender ,I tested while it was still carbed ,with a EDIS 8 & no control it ran @ a solid 10 degrees advance.

Always a good choice :-) That'll be fine, and give you some good configurability.

Give me a count & I'll make chips.I've heard that the GM optical is troublesome, but have no experience.I'll look for a Mitsi/Maz. unit.

By chips, do you mean disks? If so, what I'm suggesting is more complex than a count. With a 360-1 your best bet is a 180 degree hall or optical CAS for fastest cranking sync, with the two edges aligned to have the missing tooth fall half way between them. However, if you want to roll with the FreeEMS CAS disk setup, you won't need the crank wheel at all and can keep it as a spare in case of CAS trouble (pretty unlikely). BTW, the maz/mits units are made by mits elec just like the LT stuff, if there were really issues with them, what exactly were they? The only dead CAS units I have are ones that I broke disassembling them wrongly :-)

I'd be insulted if you insist on paying,would love to ITB a VW boxer. :D

We'll probably both be retired by the time I get around to it, but I'll keep it in mind for sure :-)

Yes is really a MS3,with a MS3x board,& white dau. bd.Is the MS3X bd. also called beta?

I'm slightly disappointed that you got an ms3 unit and fed their wallets even more, doesn't the flaky code and lack of open-ness with ms3 worry you at all? At least with ms2 you can figure out why it's misbehaving and fix it if you want. Check out the 3.1.1 release thread for examples of that.

Fred.

[gimpy]

Give me a count & I'll make chips.I've heard that the GM optical is troublesome, but have no experience.I'll look for a Mitsi/Maz. unit.

By chips, do you mean disks? If so, what I'm suggesting is more complex than a count. With a 360-1 your best bet is a 180 degree hall or optical CAS for fastest cranking sync, with the two edges aligned to have the missing tooth fall half way between them. However, if you want to roll with the FreeEMS CAS disk setup, you won't need the crank wheel at all and can keep it as a spare in case of CAS trouble (pretty unlikely). BTW, the maz/mits units are made by mits elec just like the LT stuff, if there were really issues with them, what exactly were they? The only dead CAS units I have are ones that I broke disassembling them wrongly

I do have a Honeywell hall effect sensor on order,should be in my hands by the end of next week.

By chips I mean I'll cut metal,I assume that I need X windows, with a smaller or absent window to indicate no. 1 to the ecu.I had not thought about running only a CAS,neat!!!
Actually what I had heard about GM's opti was more about the disty itself, not the sensor(Mount the dist. cap behind the water pump?)

I'd be insulted if you insist on paying,would love to ITB a VW boxer.

We'll probably both be retired by the time I get around to it, but I'll keep it in mind for sure

You've a lot more time then me,especially with the day I had today!!!!!

Yes is really a MS3,with a MS3x board,& white dau. bd.Is the MS3X bd. also called beta?

I'm slightly disappointed that you got an ms3 unit and fed their wallets even more, doesn't the flaky code and lack of open-ness with ms3 worry you at all? At least with ms2 you can figure out why it's misbehaving and fix it if you want. Check out the 3.1.1 release thread for examples of that.

At the time I bought the kit it appeared that FreeEMS was a good bit away.The lack of open-ness is a big worry.But to quote something you wrote somewhere " My art is in code" My art is in (metal) chips,not in code,I don't have a clue about writing code, let alone fixing it.I'm at your mercy

Gimpy

PS I did get this Flaptop to uncrash ,sometimes a fella gets real lucky!

[longracing]

Great looking manifold & throttlebodies.
What size injectors are you using?

I was considering doing something similar but ended up buying a Holley/Weiand Stelth-Ram manifold. I might have to modify or manufacture a new plenum to get it to fit under the bonnet though.