CB Performance dual throttle body injection

[mikey]

Has anyone tried this setup for induction? I remember I spoke with Jake breifly on them, but I dont remember what he said the drawbacks were. Can anyone chime in??? Jake???

Mike

[cnavarro]

For the money, there's nothing better in the way of fuel injection for off the shelf kits, especially for under 2k. Usually a custom efi setup runs 4-6k, depending on the level of complexity and detail put into making the system. I have a few customers running them and there are no complaints from them, other than they act like carbs in really, really cold weather since there is no cold start on them. One of the list members on shoptalkforums.com has worked on modifying a set with independent cold start and idle air regulators to improve cold weather driveability. Time permitting, I wanted to try the setup myself such that I can truely recommend the system when I am asked my opinion on it.

Charles Navarro
LN Engineering
http://www.LNengineering.com
Aircooled Precision Performance

[Bleyseng]

I saw this set up on the 914lite car. Works ok, but its not very adjustable.

Geoff

[Scrappy]

Since I haven't seen one, if it is a true Dual TBI, mounted in the center of the engine, with runners to the cylinder, you might as well run a single two barrel carb. You would suffer the same unequal mixture distribution due to the plenum feed and distance to the port (possible fuel dropout).

Port injection is the best for mixture control. No long runner for fuel to drop out in.

[JmuRiz]

Scrappy,
It looks just like a dual webbers set-up, no long runners like the POS single 2-bar webber. I personally don't see the point of FI if there is no improvement with cold starting etc, but that's just me.

Nathan

[Scrappy]

Thanks, at that point I can't see any advantage other than the possibility of larger diameter intake. I had a guy buy a set of Weber bodies from me to do the same thing. All he wanted was the butteryflys to control air and bored the body to fit injectors. I was always in a quandry as to how the air flow was measured to run the injection system.

[Dave at Pelican Parts]

Those get run as an "alpha-N" system, where alpha is the throttle angle, and N is the engine speed (in RPM). You can guesstimate the amount of air going in if you know the throttle position and the RPM. That's what those systems do, instead of measuring it in any way.

They tend to be much less accurate than speed-density systems (like D-jet), or than systems with an air flow meter (like L-jet).

--DD

[mikey]

So would you sway towards carbs DAVE?? If it were between the CB kit and webers. I dont want to start the whole fuel injection vs carbs thing.

Mike

[Dave at Pelican Parts]

Me? FI. This or another one. Frankly, I'd consider sourcing the throttle bodies from TWM directly, or converting some junk Webers, and bashing up a Megasquirt ECU to run 'em. Gives you finer control over things, and has provisions for warm-up and cold start and so on.

Don't know that I'd do all of that, but I would definitely at least consider it!!

--DD

[darisb]

Has anybody heard how the KitCarlson project is coming?

[Kevin Powers]

as with carbs you have to adjust the linkage to get them to open at the same rate. if you can't get dual carbs to work smoothly these aren't going to be an upgrade.

kevin

[Mark Henry]

I have SDS FI on a 2.0 with a scat C-25 cam, with stock TB and runners etc. and it kicks butt! No real numbers, just seat of the pants, but I may have a dyno soon, so I’ll let you know the outcome.

If your racing and at WOT all the time I would use carbs, anything else then FI is the cat"s a$$!

[Zeke]

I don't see any real advantage to TBI, but a modified TBI like Dave says with an ECU could be interesting. I'm far from an expert here, but I have a GM TBI on my truck. It's a carb to me, just a little less messy without floats and all. Anything like that might be good in the corners.

[Dave at Pelican Parts]

This is actually more of a port injection system than a TBI. Yes, the injectors are in/near the throttle bodies, but there is one throttle body and therefore one injector per cylinder. When I think "TBI", I think of a common-plenum manifold and one or two injectors in the single throttle body that feeds that plenum.

The CB setup (and similar setups) fire right down into the intake port, instead of into a chamber that has air going every which way. I think that's a better thing...

--DD

[MLedesma]

I have been watching this forum for a long time (since before there was a 911 section), and have always bought my parts from Pelican. However today I think I actually have something to contribute.

I have also seen the setup available with a turbocharger (please don't flame), from CB performance. Has anyone used this setup or seen it run.