mke
mke Reader
8/1/19 9:35 a.m.
SammyPati said:

Hi

With the ITB setup ,  the circuit diagram shows a TS951N , I assume this is a comparator?

I can’t seem to find those anywhere, are you sure that is the correct code for it?

 Thanks

Sam

That's a OLD drawing I found on the MS forum years ago....the part is an op amp but it looks like the PN is obsolete. I am NOT an electronics guy so op amp is all I know for sure blush   I had someone else help me and what I am using with all the schematic and BOM and everything else needed to make it is here:

MultiMap

If there is some interest I could probably get some boards or kits made or full assemblies if there's enough interest.  I think 1 off boards are $15-$20, parts to build the 12cyl version were about $150, most of that is the pressure sensors which were like $10 each iirc.  The layout includes the ability to accept a 5V input from the ECU so there is a circuit to bump that up to 10V to make the diodes and sensor work right.....but that can be dropped and 12V input used to simplify, the pcb  board allows that too...I was worried about clean 12V and that most ECU harnesses have 3 wires going to a MAP plug, 5V, GND, signal and I wanted the pcb to accept that but it will work on 12V input.

 

The guy who designed the pcb for me can be reached here:

mail@jaredharvey.com

mke
mke HalfDork
8/1/19 3:40 p.m.
FooBag said:

Make sure you are considering friction loss in your calculations. 100 GPM will burn 9psi per 100' in 2" smooth pipe and far more in corrugated, flexible pipe.

Are you sure you want to go with an engine driven pump? This just sounds like a pain in the rear to me. If you are interested in an electric option, I could potentially help you out as I work as an engineer in the pump industry. Just shoot me a private message if you want to discuss further.

So after a few emails back and forth I may have an even cheaper solution in the form of 2 really CHEAP spa pumps in series.  Sure, the second pushed to higher pressure pump might explode, but they are really CHEAP at $250 each so it might be woth a try.

waterway 3hp spa pump

 

mke
mke HalfDork
8/1/19 3:50 p.m.

In other news I probably should fix the engine before I worry too much about the dyno working.

I ordered the head gaskets, they're custom,  several week lead and $200 fo rthe pair

I tried to order a cylinder sleeve, with shipping probably $120, but out of stock for 3-4 weeks, then I need to machine it which involves removing about 10 or 12 lbs of iron, yay.

I got a quote for the piston...you can't order 1, 2 min but there's an extra charge below 2, new wrist pin, full set of rings, $700!  WFT, need to clear that with Lana then a few weeks to make it.

 

so about a grand on the in the block stuff if the bearings and such are all good :(

 

 

 

 

oldeskewltoy
oldeskewltoy UberDork
8/1/19 6:46 p.m.

still here....  

 

SammyPati
SammyPati New Reader
8/2/19 6:55 a.m.

In reply to mke :

Im building up an old Alfa 105 with GSXR750 throttle bodies and Im using blended  Alpha-n (ITB) and Speed density but i cant seem to get it running right. I would rather run it totally on Speed Density which I think will be better.

I'll give that guy a  yell.

thanks for your help

 

Samebutdifferent
Samebutdifferent New Reader
8/2/19 7:28 a.m.

Having a spare piston, rings and wrist pin might be a good thing considering the previous carnage.  I'm assuming new exhaust seats, valves, etc. will be required as well or are you just concerned about the block at this stage?

mke
mke HalfDork
8/2/19 7:30 a.m.
SammyPati said:

In reply to mke :

Im building up an old Alfa 105 with GSXR750 throttle bodies and Im using blended  Alpha-n (ITB) and Speed density but i cant seem to get it running right. I would rather run it totally on Speed Density which I think will be better.

I'll give that guy a  yell.

thanks for your help

 

I've never had much luck with blending either, hence the multiMap.  I recently found a gen1 board partly built....there was a problem with a couple traces but I don't recall which.....Jared fixed it and I made a new board.  It's got all the diodes and caps, looks like I pulled the voltage double chip, they were hard to get......its free if you want it, but I'm not sure if I'd be helping or hurting your effort because I decided not to fix it.....and just ordering a new board is about $20, and probably another 10-15 for the parts I see (I used pretty good diodes because they makes the magic happen with this design).

mke
mke HalfDork
8/2/19 8:03 a.m.
Samebutdifferent said:

Having a spare piston, rings and wrist pin might be a good thing considering the previous carnage.  I'm assuming new exhaust seats, valves, etc. will be required as well or are you just concerned about the block at this stage?

Hopefully there will be no more carnage...I hate when stuff I work how building get all busted and broken :(

All the stuff in the block is custom long lead and the block has to be done before anything goes together so I want to get it all ordered.

The head needs a lot of labor but the parts should be short lead, the guides I make so 1 day from mcmaster for the material, valves, seats, seat are aftermarket suzuki, a week shipping from CA.  I'll probably get tht stuff ordered in the next week or 2.  I still need to pull the bottom end apart to be sure no more issues hiding then ter down the heads, get the exhaust seats out, weld up and recut chamber #8, seats in the cut, assemble......a few weeks if I stay at it a few months if I don't.  There is oil in a few exhaust ports, could be from when cylinders weren't firing or it could be something leaking....I want to look long and hard at that.  

Paul_VR6
Paul_VR6 Dork
8/2/19 8:06 a.m.

The ITB mode works really well when set up correctly. You need a good bit of data to do so, so setup in Alpah-N first to get that data. I don't really see the need for the multi-map at all with that mode and some tuning. 

SkinnyG
SkinnyG UltraDork
8/2/19 10:34 a.m.
SammyPati said:

In reply to mke :

Im building up an old Alfa 105 with GSXR750 throttle bodies and Im using blended  Alpha-n (ITB) and Speed density but i cant seem to get it running right. I would rather run it totally on Speed Density which I think will be better.

I have GSXR600's on a 4AGE running MegaSquirt.

I tried for a LONG time to run straight Speed-Density, but it just couldn't tell the difference between cruising and full throttle, no matter how finely I split the resolution on the table. Where I am, cruise is 94kPa, and WOT is 96kPa. I am very stubborn, but I gave up on this and went Alpha N.

One of the problems on the GSXR ITB's is the TPS is on the opposite end of the throttle shaft, so if there is any slop or variance or flex or whatever, you may not get the TPS responding as quickly as the pedal is. I found good success running Accel Enrichment strictly of changes in MAP vs. changes in TPS.

You will want fairly small changes in TPS% down near idle and off-idle.  Small changes of ITB throttle are BIG changes in MAP and fueling, so more resolution there is a good thing. This improved my in-traffic driveability immensely.

My goal is to run strictly off the TPS, and have the MAP continuously variable to atmpspheric conditions, but I need to refine the TP response.

Oh, if you are using the GSXR TPS, it's a piece of siezure-inducing poo.  Very poor signal from that. I machined an adapter and am running a GM TPS.

Joet43
Joet43 None
8/2/19 1:55 p.m.

   Hello Mark - I'm totally addicted to this project , makes everything I ever did pale in comparison .  I am curios about the pictures of the wounded piston , cylinder and head .  Concerning that last cylinder , the one next to the hurt cylinder . The top of the piston , the valves and the combustion chamber show little or no signs of carbon , as if that cylinder was not getting fuel . Please edify . Regards -- Joe T.

mke
mke HalfDork
8/2/19 2:04 p.m.
Joet43 said:

   Hello Mark - I'm totally addicted to this project , makes everything I ever did pale in comparison .  I am curios about the pictures of the wounded piston , cylinder and head .  Concerning that last cylinder , the one next to the hurt cylinder . The top of the piston , the valves and the combustion chamber show little or no signs of carbon , as if that cylinder was not getting fuel . Please edify . Regards -- Joe T.

Thanks for the kinds words.

Yes, clearly something was not right with #7, #12 looks the same way....I had trouble with spark on the the whole front bank at first but thought I had it sorted, not so sure after pulling the head.  I run waste spark so 7&12 on on the same signal wire and it looks like perhaps they weren't firing.  That is part of what the dyno is for, run it were I can see everything and make sure its right before it goes back into the car.

mke
mke HalfDork
8/2/19 2:18 p.m.
Paul_VR6 said:

The ITB mode works really well when set up correctly. You need a good bit of data to do so, so setup in Alpah-N first to get that data. I don't really see the need for the multi-map at all with that mode and some tuning. 

It can work well and yes getting the Alpha-N part right takes time but it pretty important.....generally alpha-n  is how my past ITB stuff has been done.  It worked pretty nice out on track setups, no real complaints there but I've always struggled to make it really dice well on the street though...its good then the next cold morning it off, things seemed to drift a bit with time, accel enrich never quite right....just little things I could never quite get the way I wanted.  

I think it just comes down to the signal.  BIG itbs let in a lot of air with small throttle movement down low and its hard to get enough resolution/repeatability from the TPS, at least it always has been for me.  Then I got it in my head that there must be a way to fix the MAP signal, the cylinders are pulled good vacuum...google found me a thread on the MS forum and something they were working on so I built one and have the best MAP signal I've ever had on any setup...35kpa at idle the goes pretty linearly to 100ish at WOT....pretty easy to work with a signal like that.  I doubt a 4 cyl would have the same result...50-60 kpa is about all I'd expect and I think what I remember seeing the MS guys got on the bie engine they hooked it to, but that is still pretty good and certainly a signal the ECU can work with.

So its not that its NEEDED, its certainly not and I'm in no way telling anyone they are wrong to do something else.  This just makes tuning easier and more repeatable for me.  

mke
mke HalfDork
8/2/19 6:45 p.m.

So I talked to Lana about ordering the piston today.....and Lana explained to me that I have a budget which I chose to spent on the wheels and dyno so until the old wheels are sold or a new budget year begins I'm not allowed to buy anything. crying

preach
preach New Reader
8/2/19 6:49 p.m.

Adulting sucks.frown

mke
mke HalfDork
8/2/19 7:23 p.m.
preach said:

Adulting sucks.frown

Yes it does......but I did overspend the budget just a bit before Lana noticed and I have dunno contr parts to play with and I cant still get the bottom end torn down and head welded up....and lower the price on the wheels to get them sold

Samebutdifferent
Samebutdifferent New Reader
8/2/19 7:30 p.m.
mke said:

So I talked to Lana about ordering the piston today.....and Lana explained to me that I have a budget which I chose to spent on the wheels and dyno so until the old wheels are sold or a new budget year begins I'm not allowed to buy anything. crying

...Yes dear

Joet43
Joet43 New Reader
8/2/19 7:48 p.m.

In reply to mke :

TurnerX19  suspected a stuck valve caused the damage. Stuck on what ?  The two PROBABLE  causes of a valve to stick are carbon build up on the valve stem causing the valve to stick in the guide . Engine too new for that to happen .And second reason is the piston hitting the valve bending the stem causing it to stick in the guide . This usually only happens if the valves float at high RPM because of weak springs or simply over reving the engine . What am I missing ??  Are the valves two pieces welded together ? Just trying to help .  Joe

mke
mke HalfDork
8/3/19 8:05 a.m.

In reply to Joet43 :

When I had the heads off to repair the water leaks I pressure tested htm using a lead-down tester and I think it was oddish compression numbers got me to decide I should also do a leak test of the valve. Which lead to a quick lap and everything sealed.  But I recall one of the intakes in #8 had an odd feel, a bit tight in the guide so I re-reamed the guide and it was better mostly....my guess is its the mostly part that caused this mess.  When the engine fired up it was quite, some time later it had developed a little tick, I figured I'd get it broken in and reset the valve....but #8 was showing low compression which in hindsight should have set of a lot more alarms in my head...that doesn't feel quite right intake valve almost certainly hung just a little and tapered a piston or developed a much larger stick for some reason that didn't left it close fully.....then it got worst. 

There is a LOT in this engine that has been changed, custom made and generally messed and not every idea works out on the first tyr.  I'll pull it apart, and recheck everything and this time not be in a rush and go ahead and assemble when there is a something that seems  like its probably ok......the valve in #8 was in that camp and so was/is the timing chain...the engine would only turn backwards the 1st time I put it together, torn apart, found nothing, reassemble, it only turns froward now???, seemed to have something to do with how I fed the chain forward ot backward, hours each time I pulled it out and put it back....found nothing, decided to run it.  This time when something is odd I'll find WFT is going on there or it will stay on the bench until I do, I have all winter before it starts to matter.

TurnerX19
TurnerX19 HalfDork
8/3/19 3:37 p.m.

I just read your reply to Joet43 and was reminded that when I rebuilt a 246 from a Fiat Dino it would only turn forwards on the stand with first assembly, and everything was timed correctly. They are that close that the slack in the timing chain/gear set causes the valves to crash with reverse rotation. I re-clearanced the piston crowns to prevent this, cause who knows when someone accidently turns it backwards from a stall on a hill or a spin out on track. It was a very small end of the crescent clearance that was the culprit on the J&E piston that is the easily available part for the 246.

mke
mke HalfDork
8/3/19 6:31 p.m.

In reply to TurnerX19 :

That was my first thought too....but I didn't find anything.  I'll look again and double check....I have all the valve lift vs position data out of dynomation and did check valve  at different crank positions and it seemed fine, but worth a second look.  I think, couldn't find it, but I think the timing chain is forming a 1 tooth loop at the bottom on 1 side or the other based oin how I feed it and that loop locks the chain.  The 400 got a revised timing chain design with a single chain that the mechanics seem to hate.  On the 412 they added a lower guide that they said was to help during timing chain service.......I think I need to make one and my problem will be solved.

 

mke
mke HalfDork
8/4/19 7:17 a.m.

This is kind of a tangent...well end to a tangent I guess.  Fri/sat I installed the lights Lana wanted over the house garage doors which  let me finish the seal molding on the new doors so they are done.  I still have maybe an hours for 1 more coat of mud to do inside the garage on the patched where I cut to run wires but right now I think the new shop project and all the other project that got linked to it are DONE! I'm FREE!

And I got a nipple on the old wheels this morning, so fingers crossed there will some be a piston budget :)

mke
mke HalfDork
8/4/19 8:05 a.m.

So while I was out working  outside the shop fall into chaos it seems.

While looking at the new arrivals from the basement shelves I found these.

They are very low cracking pressure check valves I got from mcmaster.  These were originally for q mechanical version of the multiMAP.  Each cylinder hose gets a check valve on it's way to a small plenum, then a then a needle valve of similar to allow a controlled leak so on a 4 cyl when 1 cyl is pulling vacuum there is 1 leak not 3.  I never built it but I'm pretty sure it would greatl improve the MAP signal, maybe 1/2 or so from horrible to multiMAP level. 

 

I kept them to see if I can get enough vacuum to operate my exhaust cutout valves....one more thing to make.

 

 

Knurled.
Knurled. MegaDork
8/4/19 9:26 a.m.

I know Megasquirt can do engine rotation related MAP sampling, so it only reads the signal when, say, the engine is at 45ATDC on the intake stroke of whatever cylinder (individual) you have the sensor on.

 

Personally, I'd want to quite screwing around and just stick a MAF sensor on there somewhere...

mke
mke HalfDork
8/4/19 10:04 a.m.
Knurled. said:

I know Megasquirt can do engine rotation related MAP sampling, so it only reads the signal when, say, the engine is at 45ATDC on the intake stroke of whatever cylinder (individual) you have the sensor on.

That doesn't really help anything which is why other ECUs don't bother with it.  With ITBs if you are running a small plenum setup then you always have 1 cylinder pulling vacuum while 3 are leaking vacuum so the signal is quite poor if the throttle are open even a small amount.  If you could set the cylinder timing to only read say cyl #1 and just hook the MAP directly to that 1 cylinder it would probably work but my understanding it that is not an option.

Personally, I'd want to quite screwing around and just stick a MAF sensor on there somewhere...

Careful what you wish for.  An MAF brings its own problems.   The biggest is flow restriction and they hate noise in the intake, the kind of noise long duration cams create so they can also be quite difficult to work with and always result in a loss of power compared to SD or a-N.  There is a reason most people pull them off.

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