Where to place injector bungs on Tunnel Ram manifold

[Bob Holmes]

Yes, I keep eyeing those Pantera IGN1-A's....

Can't go wrong with those...fantastic coils.

Awesome looking engine.

Sometimes I wonder if we are kidding ourselves when it comes to the injector angle. With a conventional injector, even the location shown on that manifold will cause the spray to impinge on the far side of the runner. However different areas of the cone will impinge in a different way. Given the SAE papers I've read, the big reason for trying to shoot it down the runner is to either hit the back of the intake valve or shoot past the valve in order to aid in swirl creation.

If you cannot create either of those conditions, and you're going to spray the opposite wall of the runner, perhaps your better off bouncing the fuel directly off the wall. If the idea is to condition the fuel/air load as homogenously as possible, wouldn't it be better to have the fuel all hit the wall at the same angle and present the incoming air with a common fuel condition?

Just thinking out loud here guys, I don't have an answer.

Anyhow, If I recall, there are some late model injectors that spray the fuel at an angle. If you can place the injector at a steep angle, and then have an injector that provides the additional angle in the spray, perhaps you could get close to a direct shot down the runner.

[TheSilverBuick]

Yes, I keep eyeing those Pantera IGN1-A's....

[dieselgeek]

Porn!

x2

best looking FE ever! check out the coilpacks, he's got the Pantera IGN1-A's.

[Beagle]

Porn!

[jaybnve]

On the EFI bung location, I wanted to put mine up on the runner as high as possible without compromising the angle of the injector. Here's a couple photos of the bung location on my sheet metal intake, and also what it looks like assembled on the engine. I wasn't able to get them any higher and still keep the vertical angle of the injectors.







My setup may be a special case because the intake port is so short. Measuring along the centerline of the port, from the port opening to the valve, the port is only 3" long. So, the injectors are positioned about 3 port diameters back from the valve. My guess is that on a more conventional engine this injector position would be more like 5 port diameters back from the valve.

Also, as of yet this is an untested setup. Should have some dyno data this weekend...

[jaybnve]

The rule is: if you bring the spare, you won't need it. Unfortunately, Murphy likes to go on Drag Week too. Right Bill? (2005)

I believed that rule until DW07. That year I brought a spare supercharger, and had to use it. Brought a spare oil pump and pump driveshaft, and had to use it. Didn't bring a spare tranny cooler, and had to buy that sucker...

[dieselgeek]

The rule is: if you bring the spare, you won't need it. Unfortunately, Murphy likes to go on Drag Week too. Right Bill? (2005)

[JeffMcKC]

I would put it in my parts box, you never know when something that should not ever break, will, and you will need it. They thought Doc was Crazy when he ordered 9 injectors the other day

[dieselgeek]

Should I keep the second TPS on the second TB as spare?

Sure if the TB comes with it already.

[CDMBill]

You may not recall, but I rejiggered (apparently a real word) my progressive linkage to make my single 2200 CFM deal more progressive and drivable as well.

I expect to do the same with the dual TB's. George at Accufab says they do that all the time. Now he tells me.

Should I keep the second TPS on the second TB as spare?

[dieselgeek]

Does this mean they also like more 'pump shot' at the hit? I am assuming that there might be a similar delay affect when going from staging throttle to flat floor. Even the single throttle body on the single plane likes a lot of fuel when I mat the gas pedal.

Jeff's tuned a lot like your last combo - it took a bit of fiddling with the TPS squirt to get the engine to rev cleanly under loads from zero to WOT. I remember you and Brian chopping ET off by tweaking the same thing at DW a few years back... I'd expect there to be some fiddling again on your new combo but I don't expect any stumbles that we can't get rid of.

and it may sound funny but, Jeff's dual quad TB setup makes for easy driving, linear power output with throttle position. I'm not sure how he does that - fancy progressive linkage? but it works good for street driving, some way.

[CDMBill]

Does this mean they also like more 'pump shot' at the hit? I am assuming that there might be a similar delay affect when going from staging throttle to flat floor. Even the single throttle body on the single plane likes a lot of fuel when I mat the gas pedal.

[JeffMcKC]

Bill all I can add is, tune very slow it takes 6 seconds to burn the fuel off at a idle in mine so doing a fast "sweep" up and down will not get you the tune you want to find. Tap Tap and wait and add base timing, Tunnel rams like timing

[CDMBill]

I'd say that's about right, the rails will be laid up against the plenum to get the fuel cone down into the runner as deep as possible. Should interesting to see what it wants for fuel and spark timing vs. the single 4 barrel set-up.

Won't look as cool as your set-up Jeff but it will impair my outward visibility.

[JeffMcKC]

Its very close to where mine are Bill