Club Cobra - Fast xfi 2.0

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Quote:

Originally Posted by fordracing65 (Post 1400884)

What about the fast reviews. On jegs and summit. Most awful.

You are quite tenacious I have to admit, lol

Quote:

Originally Posted by spdbrake (Post 1400886)

You are quite tenacious I have to admit, lol

Just trying to help those out who might have an FE and will be considering these systems. That's what this forum is great for. Letting others know of the good and the bad of products. It has helped me more that once. If these systems worked so well engines builders would never sell another carb again. Especially if the systems are only $500-$1000 more than a carb. That's peanuts when spending $20k on an engine.

Believe me I love efi. And probably should have gone with a multiport system myself. I went carb. It was recommended by most I talked to. A well tuned carb runs fine for me.

Just because some people are clueless on how to use EFI does not make it bad. Many people are running the Holley Dominator system on twin turbo DBW running on E85 putting down 1400 hp without a problem. It isn't self learn, but nothing is going to self learn on a radical or highly modified engine. I am using a killer cam with factory EFI in closed loop and it runs fine. You just have to know how to tune it.

Comparing a system like the Dominator to a carb is like comparing a new Corvette to a horse and buggy.

Quote:

Originally Posted by joyridin' (Post 1400941)

Your not serious are you. Comparing a multiport efi to a self learning system is clueless. Lol. I said self learning has problems. Show me where I said multiport cannot work. Lol.

Well over the last few days I've done a fair bit of research on EFI's especially self learning ones !
I have taken all comments on board, and seriously given them all consideration.
My plan is to use all the factory hardware except the ECU-which is a seriously good bit of kit but has limitations as far as blokes like us go. Any mods that you need to make tuning wise or delete wise seems to cost heaps and you're tied to an SCT tuner pretty much.
That being said I found this post on a forum which should/will (well maybe !!) clear up some perceived issues......possibly, maybe or maybe not.........or just don't give a tinkers toss :eek:

Here is some information that I think would be helpful to anyone shopping for an aftermarket EFI system.

All Self Learning aftermarket EFI systems use manifold vacuum as a measure of engine load. This is measured by the MAP sensor. Manifold Vacuum on a running engine has an inverse relationship to the load that the engine is under. At a given engine speed, as the load is increased, the vacuum goes down.

At Wide Open Throttle, the vacuum (or pressure) inside the manifold is roughly zero. At that point, the vacuum or pressure inside the manifold is equal to the atmospheric pressure (No vacuum, and no pressure).

At Idle, when the throttle plates are closed, there is some vacuum present in the manifold because the downward movement of the pistoms is sucking against the backside of the closed throttle plates.
Anything that puts load on the engine will decrease this vacuum. For Instance, it you had a vacuum gauge connected to the intake manifold of an idling engine, and the A/C compressor comes on, even if the engine RPM stays steady, the vacuum will drop.

Manifold vacuum is an excellent reference for engine load!

Engines with long overlap camshafts and/or low compression and/or small displacement can make low vacuum at idle. This is why vacuum assist power brakes are not reccomended in these applications.

The total range for vacuum in our atmosphere is from zero (atmospheric pressure) to 30 inches of vacuum (high vacuum). Most stock or moderately cammed engines will generate 15 - 20 inches of vacuum. An engine with a long overlap cam can make as little as 2-4 inches of vacuum.

The issue with an engine that makes less than 7 inches of vacuum is that when the ECU is trying to measure load, it only has a vacuum range of 7 inches or less from idle to wide open because the idle vacuum is very close to the wide open vacuum. This senario tells the ECU that the engine is almost at full load when in fact it is idling. Because the ECU is told that the engine is at full load, guess what it does? It throws a bunch of fuel at it to handle the reported high load.

For a Self Learning EFI system (any brand!) to work properly, the engine needs to produce a bare minimum of 7" of vacuum at a warm, in park idle. I would prefer that the engine makes 10" just for added margin of error.

If you have an existing running engine that you are considering converting to EFI, you can simply connect a vacuum gauge to it and see how much vacuum it is making. If this is a new build, consult with an engine building professional or your camshaft manufacturer with all your engine specs and ask them to make a camshaft reccomendation that will produce a minimum of 10" of vacuum at idle. Bear in mind that a lot of factors come into play concerning the production of manifold vacuum. Engine displacement, compression ratio, how well the rings and valves are sealing, Camshaft duration, Camshaft lobe separation, idle ignition timing, idle fuel mixture, intake manifold and intake port design, efficiency of the exhaust system, all play a part in manifold vacuum.

With a laptop tunable system like the XFI Sportsman or XFI 2.0, you have the ability to re-scale the tables in the system to get back the load resolution lost by the idle vacuum, but this does require some tuning experience, or a willingness to learn about tuning.

If you are looking to purchase a Self Learning EFI system, please have a conversation with the dealer or retailer that you are considering purchasing from. If you are an installer or dealer of EFI systems, please have this conversation with your customer before the sale. This will help ensure that the end user gets the best system for his or her application.

Quote:

Originally Posted by fordracing65 (Post 1400791)

Km647 is here. This is the thread you want to search. Barry goes into detail how the self learning would not work. Gave Anthony credit for the self learning system and upgraded to fast xfi system. 13 page I believe. I don't know how to link it to this thread. Barry builds some of the best FE on earth.

Here's the summary from that thread;

Quote:

Originally Posted by Avmaviator (Post 1260620)

Hey everybody!

After a year... here's a major update to this build. I do apologize to everybody who was following this thread, about the lack of updates. Like I mentioned to Ralph in the above post, things have been a little crazy in the last year, but it is a good crazy :)

KMS647 is...... finished! Well beside the ever ending tinkering and modifications that we car owners subject ourselves to, haha. It has been an absolute joy to drive, especially this spring/summer season. I "finished" it in April of this year. It has a couple thousand miles on it right now (the mileage on the gauge shows 19,000 but I'll get to that later). The only issues right now, knock on wood, are the cold starts, which I'll explain.

So, let's go back to a year ago. I had the car aligned, it responded well to the alignment and was driving great, except for the engine issues... A quick recap on the engine issues. We were using the FAST EZ-EFI system, with a set of TWM stacks. That system works great when using their carb style throttle bodies, with a typical intake. In that set up, there is enough length in the intake and runners that the air/fuel charge is uniform, and the sensors see a nice uniform charge (I put together an LS1 with that EZ set up, with 2 throttle bodies, for a buddy in France, and that thing runs very, very well). The issues we had were at low rpms. Off throttle, to about 1700-1800 rpms, the car surges a lot, missed, and ran very rough, to the point of being very hard (and annoying) to drive. That was very discouraging, and puzzling to us. The mixture would go rich then lean then rich, and keep going like that, producing that roughness. After playing with it for a couple of months, and talking to FAST (unfortunately who were not helpful), Barry, the engine builder who owns Survival Motorsports, suggested we bring the car to his shop in Detroit to trouble shoot it. He believed it was an issue with the engine needing a more steady load on a dyno, so it can learn and adjust it self....
So in Oct of last year we put the car in a trailer (Thanks Hal!) and put it on the dyno.

http://img.photobucket.com/albums/v7...n/IMG_1224.jpg

From 1900 rpm to redline it ran really well, and we could see the system "learn" and adjust itself, pretty neat. The lower end rpms were still causing issues. In these last few months of troubleshooting, I started to hypothesize (with the input of my "porsche engine genius" friend at Perfect Power) that the stacks were causing the issues, along with that system. Off throttle, when the butterflies open, it produces a lot of turbulent air into the cylinders. The EZ system reacted too quickly and not well to that massive amount of turbulent air that it could not keep up with the O2 readings. That brought on the rapid correction of lean to rich to lean and so on. These stacks are like 8 huge throttle bodies, so the amount of air coming in is massive. That is why the EZ system works well with a typical intake, but not well with stacks. After we confirmed that with Barry on the dyno, we decided to go to the FAST XFI system, so we could manually fix the low rpm issues.
Btw, the low rpm issues were not detected on the engine dyno because most dyno don't operate in that low range, so Barry could have not predicted that issue. I was there at the dyno and also thought it was very well tuned. Lesson learned.
It took a bit of time to get the XFI system. After that I proceeded to lighten up the complicated harness. There were a lot of features we weren't going to use so I too, them out to make the harness cleaner. I took my time with that because I really didn't want to screw something up on the harness!

http://img.photobucket.com/albums/v7...d/IMG_1497.jpg
http://img.photobucket.com/albums/v7...d/IMG_1496.jpg
http://img.photobucket.com/albums/v7...psb2b62a16.jpg
After ripping out all of the EZ harness, I installed the XFI harness. It wasn't too hard but just took time, and by then it was winter, and cold. I made a special mounting plate for the larger ecu box, so I wouldn't have to drill another set of holes in the firewall! (pics will be posted later, there are on my camera)
While talking to some XFI owners, we decided to get a dual sync distributor from Fast, so we can get sequential firing from the more powerful XFI system. The EZ uses a bank to bank firing (all injectors on one bank fire at once). That makes for a more efficient engine. Here is the distributor. Very cool unit.
http://img.photobucket.com/albums/v7...ps0ff1b8b2.jpg
http://img.photobucket.com/albums/v7...ps1339f7c9.jpg

Installed. You can see some white moisture spots on the aluminum pieces. We had a freak warm day in Chicago this winter where the temp shot up to 60 degrees. My garage which was at 30 degrees, didn't like the warm humid air coming in and everything, I mean everything, was covered in condensation. I had never seen that before. I couldn't dry the Kirkham's engine in time to prevent these little corrosion spots. Took me a while to get rid of these later!
http://img.photobucket.com/albums/v7...ps4e1b6c8a.jpg

After installing everything, and waiting for the weather to warm up enough to drive, we tuned the car. I did a lot of it myself but it was pretty time consuming and a steep learning curve. I was making progress but still couldn't get everything right. I probably could have done the whole thing but it would have taking me a long time. I gave the car to my friend a Perfect Power, who, with the help of a very knowledgeable EFI guy, tuned the car very well. It runs great. We still need to put the car on a chassis dyno for the WOT tuning. It was mostly tuned for drivability. The only issue we have, and that we can't figure out, is cold starting. During a cold start, you have to crank the car over 6-8 revolutions before it coughs to life... Very annoying. I have cranked the fuel enrichment for cold starting but nothing.... Hot starting only needs one revolution. I wish that XFI system had a pre-squirt option when you turn the keep on, like the EZ system did. That is one thing I really want to fix.

It has been great to drive! The stiff steering issues are mostly due to the teflon bushings used in the Kirkham steering assembly, and are said to get better with a couple thousand miles. It has gotten better I'm happy to report. *There is an issue with the speedometer as it shows 180 mph (pegged) when you drive, and now shows 19,000 miles, haha. I'm going to send the gauge back this winter. Other winter projects are to move the pedals right a bit. I don't like the pedal position, and it is unsafe in my opinion. A tonneau cover will be installed hopefully too.

That's all I can remember for now... Now for the glamour shots below.....

Arnaud -

Here's the non-multiport system in my last car starting. You can skip the walk around by going to about 30 seconds. There are other videos on my youtube channel as well. While I'm NOT saying that it's as easy as the advertising says, it IS possible to have your vintage looking FE (without all the wires and tubes on top of it) while still experiencing the benefits of FI.

[ame="https://www.youtube.com/watch?v=gndOcV36R-k"]https://www.youtube.com/watch?v=gndOcV36R-k[/ame]

Rog

I've got a BA XR8 with the Boss 260 sitting in the paddock. And I've got a diagnostic tool floating around. It can give live data including MAP readings. Would you like me to get the data for you. Mine is a factory engine as far as I can tell.

Dave