Anyone ever used Stack Injection ITB setup?

Larry L.

Lifetime Supporter
As you don't know me Larry I'll let you (off) with that statement.
Very civil of you.

I notice that you don't mention what ECU "all the people you know" were using, you just blanket blame it on the hardware. That seems a little unfair to me, just half the story.
First: you misquoted me. I said, "No one I know".

Second: I didn't "blame" anyone or anyTHING for the issues. I said: "No one I know who's installed an 8 stack or Weber look-alike system (regardless of manufacturer) ever got it to work right...even after HOURS of 'over-the-phone' tuning with 'the factory'."

Lastly: I have no idea (nor did I ask) what particular component/components were the cause of the problems each owner had. Obviously neither the car owners NOR the manufacturers of the various units involved did either. If they HAD known/discovered them - the issues would have been resolved, would they not? Therefore, I did not, as you are now insisting, outline just "half the story". I posted 100% of what I knew to be the case.

OTOH, you appear to be quite happy 'assuming facts not in evidence' where I'm concerned and then present the 'theories' you've formed based on those assumed "facts" as though they actually were facts. "That seems a little unfair to me."

G'night, Sir.
 

Glenn M

Supporter
Very civil of you.



First: you misquoted me. I said, "No one I know".

Exactly! Precisely! I didn't miss quote you. You don't know me, ergo what you said applies, so I let you off! I was trying to inject a light hearted tone with a bit of humour which you took completely the wrong way; lighten up.
 
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Eric B

Eric
I've run the newer version TWM/Borla Stack Injection system since day one. Although it ran pretty good with the included self-learning "EZ-EFI" after a few hundred miles of 'learning', that system is only designed to control fuel. I also had a separate computer programmable ignition box, but I wanted the ECU to do it all, have more scalability, data logging, and so on, so I traded in the EZ-EFI v1.0 for their FAST XFI Sportsman, which accomplished everything I was looking for. The XFI 2.0 is fine, but is overkill for a vintage-looking GT-40, unless you plan to go with a modern fully sequential with coil-over-plug setup, and have full fuel and spark timing capability from cyl to cyl, i.e. 8-1 cyl engines.

There are a few hidden pluses to the Borla system, which I like. The hidden under the manifold vacuum chamber, the under the throttle plate injectors, center mounted fuel rails that properly angle and feed the injectors under the throttle plate, and probably the least noticed but important design is the flex couplings that are unique to the Borla. As these manifolds get hot and you have dissimilar metals expanding at different rates, these couplings flex axially, which help to minimize the interaction between the throttle bodies and butterflies, so they are binding against each other. That can cause rapid throttle bore wear, which eventually results in air leaks when the throttle plates are closed (idle) and all kinds of syncing issues since you have some cyls getting more air than others even when the throttle plates are closed. Getting each throttle body flowing the same amount of air next to each other and bank to bank are one of those key elements to getting these systems to run well. The throttle response is incredible. Not sure what the cfm rating is on the 50mm throttle bodies, but it has to be in the 1000s!

That all said, no one's mentioned the exhaust system and how well it's sealed in and around the O2 sensor(s). This is critical feedback for the ECU, so if it picks up air from an exhaust leak, you are throwing your money away and end up with a $hitty running system. So not only figure out your budget for the stack setup, also add in an EFI purposely-designed for EFI bundle of snakes. People like to blame the EFI for a poor running system, but there's a good chance little or no attention was paid to the exhaust system. Tip: Look for double-slip joints at the header-collector union, V-band clamps at the collector-muffler union, and nice thick header mounting flanges.

I have over 8000 miles on my setup now. Starts cold (tested to 20s F) and I have tested it in stop and go traffic at over 8000 feet, high water (230) and (240) oil temps, 190+ deg intake air temps, too. I've purposely stressed tested it so I could work out any bugs, and in hope that the car wouldn't let me down on a drive. Last thing, if you happen to live in or near the mountains like I do and see anywhere from 5k-11k feet of elevation (810mb ~ 670mb) change during a drive, you can wire in a second MAP sensor so the ECU sees the pressure changes and adjusts the parameters as you drive....nice to have.

In a nutshell, it runs pretty damn good and looks the part to the untrained eye!

View attachment 106872
Tom, do you normally run without air filters?
I plan on using the small K&N filters, but I see many GT40's without.

E
 
Tom, do you normally run without air filters?
I plan on using the small K&N filters, but I see many GT40's without.

E
Yes, I do.

However, I sample my oil every 2k miles or each year to trend silicon and other elements to help prognosticate high wear items. I perform compression and leak-down checks every year as part of my 'annual' and they are all excellent. I also drop the oil pan (easy to do) and inspect the lower cyl walls, remove/inspect/or replace the oil pump, and inspect the oil pan. The oil lab report does show a rise in silicon, however, the iron and chrome analysis (rings?) are well within specs. Valves, lifters, cam, crank, cylinder liners, oil pump, and timing chain/gears are all possible sources of iron. It makes up the bulk of wearing parts in this type of engine, so the exact source is hard to narrow down. I will say that if dirt is causing premature cylinder liner wear, we would expect to find high iron in analysis. Maybe chrome too, from ring wear. The fact that iron was okay in my report suggests the bulk of extra silicon may actually be from something harmless like the sealer that I use around the oil pan. The engine has around 8000 miles on it so it's possible wear will accelerate with time, but the trending will show it. Time will tell...

In my opinion, I think most of us end up playing with engine combos, replacing, or upgrading our engines before they truly wear out or need a rebuild anyway. So unless you drive regularly on long stretches of dirt roads, or drive through a dust storm, or plan to keep the motor for a 100k miles, you should be fine. Just consider more frequent oil changes, periodically check compression it should be a relatively easy thing to stay on top of.
 
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Self learning works for a bit. It helps you to even out the VE table but this only works if the basic parameters in the AFR table are set correct.

I have some experiance with Megasquirt MS2 and self progamming it.
In basic you need an AFR table that calculates an amount of fuel needed to reach a certain Air Fuel ratio under certain conditions.
Most pre set ECU's come pre progammed to work in avarage conditions like a heavy Mustang.

Thats where the VE (Volumic Effecientie) table comes in. As the AFR table only calculates whats is needed to reach a certain AFR level at any point, its just an estimation. It guesses what it needs to spray on fuel to get there but that doesn't actualy mean it reaches the AFR level you wish for.

The VE table is many times overlooked. In the VE table you control the amount of fuel injected to actualy reach the AFR level in the AFR table.

Most self learning and auto tune options do actually the math and correct the VE table so your engine runs the AFR you need to run properly.
But that only works if the AFR table is set correct.

Most ECU's are preprogammed to run a 4 barrel Holley style TBI injectors, wel that will idle fine at 14:1 AFR. Will cruise nice at 14.7:1 AFR and WOT on 13 to 13.5.
On an 8 stack that aint going to work.
Like quad Webers it probably wants an idle of about 12.8 to 13:1 as its IRS design has less vacuum on the intake runners. Its needs to be compansated with more fuel. Cruise will probably around 13.5 and WOT in the 12s.

On a properly set ECU, it realy doesn't matter if you spray ontop of the butterflys or below, but spray pattern does influence a lot.
I had a 12 hole injector spraying causing lots of issues especialy on a heat soak start. I switched to a single hole injector and it made a whole lot of a difference.

So you need a ECU program that is set for GT40 conditions (lighter car and more aerodynamic than a Mustang and engine in the back with heat soak issues) or somebody that knows what he is doing and knows how to correct a VE table.
Lots of dyno operators still do not understand the importance of the VE table and ignore it sending you home with a car running crap wishing you never went the EFI route and sticked to the carbs.
 

Dave Hood

Lifetime Supporter
Eric, just my opinion on filters. I'd never risk my engine with either no filters or just small mesh filter caps that some people use on their eight stack systems. I use the K&N filters that are similar to those used by Roush on their engines.



K&N.jpg
 

Eric B

Eric
Eric, just my opinion on filters. I'd never risk my engine with either no filters or just small mesh filter caps that some people use on their eight stack systems. I use the K&N filters that are similar to those used by Roush on their engines.
Dave, I am of the same mindset. But I like to hear what others are doing.

E
 

Bill Kearley

Supporter
Dave are they Borla in post # 47 ? K/N and Roush have a thing going, Pay double for the 8 push ons made in the US. They do not show up on the K/N site.
 

Dave Hood

Lifetime Supporter
Bill, you're right. They do not show up on the K&N website. I think they're made specifically for Roush. I called Roush here in Charlotte and picked them up at their shop. They were not inexpensive but they were willing to sell them to me. I felt they were the best way to protect my engine.
 

Eric B

Eric
Bill, you're right. They do not show up on the K&N website. I think they're made specifically for Roush. I called Roush here in Charlotte and picked them up at their shop. They were not inexpensive but they were willing to sell them to me. I felt they were the best way to protect my engine.
I have a set that I believe Dennis or Rick "procured" for me. ;)

You are near Dennis's shop then?

E
 

Eric B

Eric
^^^THAT'S S-T-U-N-N-I-N-G!!! ^^^

(I'm glad YOU have to keep it shinny and not me though!)
Larry, I don't know how it will be with polished stainless headers. I have Firefly SS side pipes on my Cobra, and they do "gold" after maybe three years after I first got them. For a winter project I pulled them off and polished the gold out. Then about 5 years they gold, and some "splotches" (technical term), but I pulled them again in the winter, polished them again and they look great. I do not know how much faster these will gold, I will have to see. But if they do I won't have time to spend in bars with fast women next winter. :p

E
 

Larry L.

Lifetime Supporter
Larry, I don't know how it will be with polished stainless headers. I have Firefly SS side pipes on my Cobra, and they do "gold" after maybe three years after I first got them. For a winter project I pulled them off and polished the gold out. Then about 5 years they gold, and some "splotches" (technical term), but I pulled them again in the winter, polished them again and they look great. I do not know how much faster these will gold, I will have to see. But if they do I won't have time to spend in bars with fast women next winter. :p

E
Did you have them coated INTERNALLY with ZyCoat or Jet-Hot or the like?
That ought to stave off the "golding" to some degree, shouldn't it?
 

Glenn M

Supporter
Larry, I don't know how it will be with polished stainless headers. I have Firefly SS side pipes on my Cobra, and they do "gold" after maybe three years after I first got them. For a winter project I pulled them off and polished the gold out. Then about 5 years they gold, and some "splotches" (technical term), but I pulled them again in the winter, polished them again and they look great. I do not know how much faster these will gold, I will have to see. But if they do I won't have time to spend in bars with fast women next winter. :p

E
Blimey Eric, three years! Mine went from shiny to gold in one trackday! I must get some of whatever you put on yours. ;)
 

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Eric B

Eric
Did you have them coated INTERNALLY with ZyCoat or Jet-Hot or the like?
That ought to stave off the "golding" to some degree, shouldn't it?
Yes, there is a ceramic coating on the inside of the headers in the picture above. I have seen two other GT40's with these headers, and they seem to be doing good to keep the golding off. A lot of that has to do with if you drive in the rain too, which normally I do not.

E
 

Eric B

Eric
Blimey Eric, three years! Mine went from shiny to gold in one trackday! I must get some of whatever you put on yours. ;)
The three years was on my sidepipes for the Cobra. Here it is last year, about 1-1/2 years after taking them off for the second time and working the gold off them.
firefly side pipes.jpg


But I do not know how the headers will be yet. We will see.

E
 
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