I thought I'd share what has been quite the rewarding experience with MS conversion of a perfectly good setup.
Chevy 454 over 0.030 with 8:1 pistons, Comp Cams mild retro roller blower cam #11-409-8, basically stock 2 bolt bottom end.
GMC 6-71 blower underblown 13%, figuring 600HP using a computer engine simulation dyno run.
This setup was originally fed with 2 Barry Grant 850 blower (boost referenced) carbs and ran over 5000 miles.
This engine was sitting in a 1923 Ford Touring T street rod (basically a stretched T bucket)
This engine now has 8 44lb high impedance injectors mounted on a plate above the blower, hidden inside an Enderle Bug Catcher Injector Hat, fuel fed through the original injector ports that were designed for constant flow fuel injection. Fuel is fed up to a fuel distribution block with a Mallory EFI return style system. Each EFI injector is fed individually by stainless lines from the distribution block. See url - http://www.hilborninjection.com/product ... &CatId=175
for similar approach, except for the individual fuel lines. The individual fuel lines can be seen here - http://www.goodvibesracing.com/Product-Scans/E-1006.JPG
and here - http://s590.photobucket.com/albums/ss34 ... g&newest=1
It was a scary thing, tearing into what was a perfectly good setup on carburetors. That was probably the hardest part of the installation, making myself actually get started, and in the middle of show and cruise season to boot. It really helped that I had the ECU installed in the car for about a year with all sensors hooked up and running. My Innovate LC-1 wideband O2 sensor and gauge has also been in the car that long. The gauge is on my dash and helped me fine tune my carbs in the past. I was able to do some datalogs on the existing setup to retrieve all my mixture settings as well as verifying all sensors were working properly. When I changed over to EFI, I had the injector hat sitting on top of the mounting studs so I could check firing of the injectors both during priming pulse and cranking. After chasing a couple of slight fuel leaks, I fired the engine. It lit right off! It was wicked lean until I bumped up the req_fuel from 41.9 initial to 16.1. I suspected maybe a little longer injector opening time might be in order, but I haven't changed it yet. I'm still running with the req_fuel at the 16.1 point. Then I started fooling with the VE boxes around idle and got idle smoothed out. It wants to idle at around 900 - 950RPM in park and about 750-800RPM in drive. The mixture seems to be best at about 13.5:1 at idle, just like Megamanual says. It has taken me about a week of fooling to get rid of an idle roll, and the key was getting the idle speed right. Any lower and it would start to roll, sometimes extreme. The other thing that has taken some time was accel enrichments. It doesn't take anywhere near what I thought, and you can see it's effect directly on the datalogs when driving. Since then I've been playing with cold start and hot start settings. I haven't gone closed loop yet, so my setup is only roughed in at this point. I'm attaching a msq data file in the hopes that this will help someone get a start with a setup that might be comparable to mine. As I get a better fine tuned file, I will post. MS rules the roost! It beats all the other more expensive systems completely, both in price and functionality. Good luck! Dan - Touring-T
Nice ride! Yeah, a little over the top - that's what this is all for. Otherwise, we'd all be driving Yugo's and loving it. Nice fabrication work on all the piping. My Willys is at a local hot rod shop. They've been waiting to see how this Megasquirt thing works out. Once I got the T bucket running on MS, I think I really made them stand up and notice. I'm thinking that a couple of these guys are going to want help with converting their stuff to MS sometime soon. One of the guys has a blown 427 in a 69 Chevelle Pro streeter, and the other guy has a Corvette LS engine in a 66 Nova. Both conversions should work out pretty well. I can see this shop becoming a Megasquirt expert shop. Next thing is we'll need a chassis dyno!
Nearest I can figure is that running MS is about half the cost of running any commercial off-the-shelf EFI system. Not too shabby return for a little bit of brainwork. I'd really like to see some dyno runs with some guru running MS to see how it's done. If there aren't date conflicts, I may try and get to the Megasquirt Meet next year.
Good luck with the pickup!
I had a good verbal altercation with a rather arrogant punk in his 20's. He and his buddies were studying my setup at a local cruise when I walked up. He asked about my WB gauge and my rs232 cable in the car. He wanted to know if I was tuning my car with it. I said yes. He then asked why I was running mechanical FI! Well, I finally got someone that "thought" they knew what they were looking at. I told him that there was EFi injectors underneath the hat. He then proceeded to tell me he had 6 years of EFI experience with various systems such as FAST and ACCEL DFI on LS engines. Then he asked the million dollar question - what ECU was I running? I told him Megasquirt. I thought he was going to split a gut! He said that MS doesn't do true speed density. I said how come? He then listed all the sensors that the other systems use that megasquirt doesn't. I told him to list them for me again. As he went through them all, I pointed to their location. I then said I can show him the speed density equation if he wants. He said they must've made some improvements. OK, this guy is full of c##p already. He was in my face about how I can't get that system to run properly, and that I should allow his expertise on a different system. I told him it ran fine. He then started in on cam specs and how I need to be provided a base map to start with and he'd help out. He couldn't understand how I wasn't running spark control, also. I told him I had 5 years of old fashioned carb and distributor tuning on this engine before EFI, and I know what it wants. Finally, I told him that if he ever wants someone to accept his services that he better back off just a little and understand that there are other ways of doing things besides his way. He told me to get a book and study it. I told him I'm a computer engineer and a street rodder and understand these systems. Finally, I told him it's a shame he's so arrogant, that I'd love to chat about these systems if he were a little more pleasant. I walked away. I had to share that.
I started finding some of those videos. There's a ton out there. I've learned a lot about running megatune that way. I'd love to witness a dyno tuning session with an MS system. I wish there were more guys around here. I know of only one and he's the one that started me down this road. I made a good friend that day. Yes, MS makes you really understand the whole picture, not just follow dialog and have the ECU do everything. I have a friend that's running Electromotive and WinTec3 on a Ford 460 with individual Hilborn style injectors in a 32 Ford 5 window coupe. Killer injection system, but nothing over MS as far as the ECU is concerned. I hate the interface software. It's not intuitive at all. He's not a computer guy at all and he's struggling. I help with what I can. but it takes me so long to orient myself to their way of doing things that I burn all the time figuring the software out. I'm waiting for him to get fed up with it and I'll convert him to MS and be done with it.
I hope the tuning went well. Did you take any videos of the pulls? What's the final goal for boost pressure? Good luck with it!
Well, I solved a lot of the problem with acceleration, hot starts and a host of other pain in the butt issues. My IAT sensor is below the blower, sitting in the back of the plenum just below the back of the blower. I had a lengthy discussion with a fellow 'Squirter that had a blower on a modular 4.6 Ford. He sensed IAT below the blower with no issues. The idea was, blowers generate a ton of heat, and that's the temperature of the incoming air to the intake ports, so by allowing MS to measure that, the mix will be right for real temperature of the air going into the engine. That is well and good if fuel is being injected at the ports. For those that are injecting above the blower, like me, it just tends to screw things up, and I've been chasing them for a while now. I noticed that BDS, Kinsler and Hilborn all sense IAT above the blower where they inject fuel in their EFI setups. I always thought that wasn't the best place, until today.
I'm injecting above the blower. That's where the mix is occurring, and that, I believe is the correct spot for measuring IAT. I think the IAT needs to be upstream of the mix, but close to the temp where the mix is occurring. So today, I basically negated any correction of my IAT by using the IAT correction curve to undo any influence of the IAT to the mixture. Low and behold, everything changed, for the better. I no longer have the lean spot showing up after a throttle change or tranny shift. I no longer have hot start issues. I can dial in my VE table much cleaner now. The car is driving a whole lot better now.
If I were to change my intake so that I could inject below the blower, at the intake ports like my buddy's, then the IAT needs to be below the blower. Otherwise, stick it above. I also question how much of my problem was from just plain heatsoaking the IAT from the intake itself.
I just thought I'd pass this along for anyone else trying to 'Squirt with a blower setup. As soon as I back off now on a couple of my accel enrich bins tomorrow and test it out, I'll post my msq and log file.
I am building a very similar settup to yours with a few differences. Even the car is similar. 31 Model A coupe, 468 BBC converting from two 850 Holleys. 871 overdriving 12% at the moment. I was just having a discussion about the air temp the other day and my thinking was to measure above the blower so nice to hear I was on teh right track.
So the big difference is that I am using an old Enderle sbc mechanical port injection manifold that I am modifying to put on top of the blower!! Yikes! I cut apart the original and am in the process of building my own intake to accept the 4 individual throttle (two siamesed together in each) bodies that I am left with. I am going to be hiding the injectors inside the manifold and plan to use the original fuel/injectors for my idle air circuit as well as machining out the barrel valve to hide the tps sensor inside. My goal is to make it look as though it is entirely mechanical injection with 8 stacks on top of the blower.
Thanks again and any additional tips for the newbie are greatly appreciated.
i'm also doing a very similar setup 8-71 468 ls7 bottom end 8.5:1 pistons, brodix bb 2xtra heads, 260/270 @.050 .685 lift mech roller my dyno simulator says close to 1000hp its going into my 57 chevy 2dr ht backhalf 4link car i hope the megasquirt will be ok with a somewhat radical combination like mine