Dougs951S

Just wanted to expouse some praise here for a change, for a great product that completely transformed my car. Nearly 9 months of fiddling with it off and on (mostly off) I finally finished fine tuning my car tonight. First off, I'm totally impressed with myself and how easy it was to set everything up and get it right the first time using tunerstudio and a wideband. Going from a map that wouldnt even start the car to one that gives me perfect A/F ratios took about 3 days of road tuning by myself. The idle is smooth as silk, way better than stock even though I have 80# injectors.

The best part is definitely the datalogging. Oh dear god, there is so much data to log! I can finally see how efficient my FMIC is at removing charge heat. I was totally blown away to find out that even on multiple back to back pulls from 40 to well over 100, the intake temps measured right before the TB never got above 90F. I would never in a million years have guessed that the temps would stay within ~20 degrees of ambient. looks like I don't need an intercooler sprayer after all. Interestingly though, the intercooler did get heatsoaked sitting in traffic in the texas sun, I recorded temps of over 120 sitting in rush hour. I am also totally blown away by how fast I'm achieving positive pressure now, I'll have to figure out how to turn my megalog datalogs into excel graphs. I'm seeing positive pressure in 1st gear at 2700 rpm!

The throttle response is sharper than any other car I've ever driven. 8 lb flywheel + zero intake restriction = throttle response that totally blows away the DME. It's sharp as a razor downshifting, and just overall way peppier around town off boost. That is of course from the fact that I now have optimal timing at all times. rolling into the boost gently from a cruise, there isnt that "Dead spot" we all know and hate, it just pulls smooth as butter, harder and harder to redline.

I'm definitely making more peak power too, in addition to have way more area under the curve. The car just plain pulls a lot harder than it ever did on any other tune I've ever had. I know there is more left on the table, need to get this thing on a dyno now.

Oh, and did I mention I'm getting better gas mileage now? since I have lean cruise set up, I'm usually sitting at ~16:1 A/F on the highway and I've gone over 500 miles on my last tank, with fuel still left. I wish I had squirted my car years ago, in hindsight it was so simple to set up and its all pros, no cons. I really want to get people excited about EMS on these cars, I hope to see more setups like mine coming soon. If anybody would like some information, I'll happily and publicly share my ignition and fuel maps and anything else anybody would like to know about my setup, VR sensor bracket, trigger wheel, ect.

Thanks

Butters944

Only prohibiting con I'd think of is cost - mind sharing how much you've invested into the squirt?

Dougs951S

Well, it depends on how you figure it in. Most 951 owners including myself already have a wideband, but if you were trying to squirt an N/A you'd still need one, so that's 200 right there. The actual squirt cost me 300 bucks or something in that range, and it came with a MAP sensor and two GM IAT sensors plug their respective pigtails, and like 50 yards of different colored wiring. I stuffed the whole thing into an old gutted DME box I had, so that can cost anywhere from free to ~50ish bucks? The crank trigger wheel was specifically built for the 944 crank pulley, I got in from GoingSuperFast and it cost me something like 40 bucks. The VR sensor I ripped from an old 1.8 liter ford escort, I think I paid 2 bucks? Also got a broken stock 944 speed sensor for free and cut it up to use the connector to wire the ford sensor into the stock harness. I built the bracket myself out of a 5 dollar piece of hot rolled 24x1x1/4" steel. The style I made works really well, but would only work if you didn't have AC AND didn't have power steering AND ran without belt covers. Other bracket designs could easily be made, thats just what worked for me. My 80# injectors were ~180? Other little things I needed were resistors for the injectors, I dont remember how much they were but not much. Also had to buy a BIP373 ignition coil driver because the specific megasquirt unit I am using only outputs logic level signals to drive smart coils with built in igniters, like ls coils. That ran me 10 bucks. I build a heatsink and seperate housing for the ignition driver to keep it cool and isolate it from noise, I used some scrap steel and aluminum I had in my garage. Oh, and I also had to buy a R232 serial to usb adapter cable to communicate with my laptop, I think that was also 10 bucks. Finally, the full version of tunerstudio MS cost 60 dollars, but was worth absolutely every penny. I could have set the car up with the free version, but it was just so much easier and faster with the paid version that it paid for its self in 10 minutes. I think that's pretty much a complete cost list, so total cost for me was just under 600 bucks with a few upgrade parts included. Depending on what you have/dont have I could see someone spending 800-900 bucks on a setup like mine, but it really can be done pretty cheap. Definitely under a grand all in pretty much no matter what, and potentially under 400 bucks depending on how much power you're after. An N/A would cost more than a 951 I think just because other parts are involved, such as needing to find a 951 TPS, finding a spot to mount the IAT sensor, ect. A 951 that had a wideband already and wanted to stay with stock injectors could be done for maybe 375ish if you were willing to do some junkyard hunting for sensors and what not, otherwise you can easily spend 100+ bucks on sensors alone.

PorscheHour

That's really amazing, doug. Your car sounds incredible. Drive it fast and turn it hard, as Mr. Porsche might have said. I'd like to see your data and charts if possible. Can you post anything here? Thanks and enjoy that beast!

konakat

So you have completely eliminated the DME, right? What are you using to measure airflow, the stock AFM or an MAF conversion?

turboS_swede

MegaSquirt can use an AFM, but it requires some work to configure it that way and there isn't a lot of people using it that way. It is meant to use the MAP sensor to read the pressures in the intake, so there isn't a AFM/MAF needed which can help clean up the intake path a bit and gain a couple of HP.

The gain in HP is even better on the CIS cars since the CIS air meter system restricts air flow quite a bit.

To avoid the resistors that the OP used, you can use high-impedence injectors, buy a fly-back mod kit for the MS1/MS2 V2.2 board or if you have a newer board (V3.0/3.57) you can buy a Peak&Hold board from JBPerf which opens up the ability to run sequential injection to help improve idle quality.

Fly-back board for MS Version 2.2 boards

JBPerf Peak&Hold Board

When you're ready to buy, I'd buy from DIYAutoTune.com. They are a great group and really know their products and can get you setup with everything you need.

For those of you with 16-valve cars, there is even a break out board available to help speed up the wiring for MegaSquirt: http://www.diyautotune.com/diybob/index.html

Dougs951S

Right, there is no air metering device, im tunes using the speed density algorithm. Also, my 80# injectors are high impedence measuring 12 ohms each. The resistors are in use because originally I set the car up with the stock low z injectors. I run semi sequential fuel but plan on adding a cam synch soon to allow full sequential and COP ignition with no distributor. A custom build ITB intake with hayabusa throttles is also in this car's future.

Chunkerz

Does Mega Squirt fire each injector individually (I think they call it sequential injection?), or does it still batch fire them?

Dougs951S

It is very capable of sequential injection, but that requires a cam synch and removal of the distributor so that megasquirt knows which cylinder is on its intake stroke. Right now my fueling is semi sequential, it fires the injectors in pairs. My idle is better than stock even with injectors more than twice as large. Once I make the switch I'll also be direct firing GM truck LS coil on plugs.

Chunkerz

Nice. Post some videos or pictures of your set up. I'd like to see it.

Is it not possible to use the crank position sensor to determine which cylinder is on the intake stroke?

dlr944

Is it possible to see the kit in austin sometime?

Dougs951S

No, since a full cycle in a 4 stroke engine is 720*, without a sync from the cam which rotates at 1/2 crank speed (and therefore does 360* rotation in one cycle) the ecu has no way of knowing if the cylinder its about to inject fuel into is about to be on its intake stroke (ideally you want fuel to be injected just before the inlet valve starts to open) or is 180* away on the very beginning of its power stroke.

dlr, yes I've be happy to show you the car, I'm in Austin all the time. I'm currently in the middle of installing my Sparco seats so it should have a fresh-ish interior as well.

Chunkerz

I see. Never mind then....

Will Feather

Congrats Doug, thanks for the info a few weeks back about your setup.

I would love to MS one of my cars soon, pending funds and available time. Got a link to the crank pulley?

Dougs951S

http://www.goingsuperfast.com/Trigger-wheels.html

I used the 6" pulley, can get some pics up tonight but the car is currently down, and will live again some time next week distributorless and running LS6 COP's in wasted spark. Dizzy's are so 80's, trying to get away from all that.