"vacuum gauge" to balance stacks?

kobrabytes · #1 (**permalink**) 03-18-2009, 05:54 PM

Can anyone point me to a place that I can buy the vacuum gauges to balance my TWM stacks?

THanks in advance

len

bobcowan · #2 (**permalink**) 03-18-2009, 06:56 PM

This is what I use. Can't remember where I bough it, though.

http://www.compperformancegroupstore...ory_Code=TOOLS

sllib · #3 (**permalink**) 03-19-2009, 04:43 AM

Would a motorcycle set-up work?

sicilian cobra · #4 (**permalink**) 03-19-2009, 05:48 AM

Maybe this will work
http://www.eastwoodco.com/shopping/p...word=colortune

kobrabytes · #5 (**permalink**) 03-19-2009, 06:38 AM

I believe my throttle bodies are 58 millimeter, are the bike ones large enough?

Gaz64 · #6 (**permalink**) 03-21-2009, 03:58 PM

Two sets of these would give you the best balancing system:

http://cgi.ebay.com/ebaymotors/ws/eB...3AIT&viewitem=

If you have a vacuum port per runner which are all gathered for vacuum brakes, then just disconnect the plumbing to hook up the gauges to each runner for idle balancing.

kobrabytes · #7 (**permalink**) 03-23-2009, 08:29 PM

Nice, yep that would be accurate.

There are ports on each of the stacks, just really hard to get to once everything is put together.

I like those.

kobrabytes · #8 (**permalink**) 03-23-2009, 08:31 PM

A friend pointed me to these on the weber site:

http://www.webercarbsdirect.com/BK_p/bk.htm

Like those in the first response, but less money!

RICK LAKE · #9 (**permalink**) 03-24-2009, 03:12 AM

kobrabytes Get them from the weber store, they are cheaper. Also make sure they have the right size rubber grouments for your throttle bodies with the meter. Buy 2, it saves time when setting up. Mine are still in the box. My install the 58mm on the 482 this spring. Will see. Rick L.

kobrabytes · #10 (**permalink**) 03-24-2009, 12:11 PM

Thanks Rick, that was what I was thinking.

I bought a dual sync from FAST, I like the setup and am not sequential. I put the FAST into alpha N, slowly working to get the tables rebuilt. Getting the MAP sensor out completely got rid of the backfire.

Do you have any samples of the base fuel, A/F, and spark tables for your setup? I want to see how the 3D graphs compare to the speed density.

Making progress!

len

twobjshelbys · #11 (**permalink**) 03-24-2009, 02:12 PM

I got this one:

Edelbrock 4025 Uni-Syn Carburetor Balancing Instrument

http://performanceparts.com/part.php?partID=64554

but I got it from Amazon because it was cheaper (no shipping charge for 2 day shipping because my wife signed up for a fixed price shipping deal). Ignore the picture on Amazon, the part number is correct.

kobrabytes · #12 (**permalink**) 03-24-2009, 07:43 PM

How large of bore do they work with?

RICK LAKE · #13 (**permalink**) 03-25-2009, 04:18 AM

kobrabytes Len I am running alpha-n on my car since the 482 is in the car. My laptop battery crapped out and kill my laptop. I only have a sloppy disc right now and no way to transfer it to anything. The other thing is every motor is different and my custom setup will not help you at this time. I am running 50 pound injectors with 52 psi fuel pressures. At WOT my duty cycle is 61%. Idle pressure is 44 psi fuel. Fred Kemmer may be able it shoot you a copy of his setup. He's running XFI and 58mm's. May computer in the car is an old Speed-Pro, about 10 years old. Rick L.

kobrabytes · #14 (**permalink**) 03-25-2009, 02:00 PM

Quote:

Originally Posted by RICK LAKE

kobrabytes Len I am running alpha-n on my car since the 482 is in the car. My laptop battery crapped out and kill my laptop. I only have a sloppy disc right now and no way to transfer it to anything. The other thing is every motor is different and my custom setup will not help you at this time. I am running 50 pound injectors with 52 psi fuel pressures. At WOT my duty cycle is 61%. Idle pressure is 44 psi fuel. Fred Kemmer may be able it shoot you a copy of his setup. He's running XFI and 58mm's. May computer in the car is an old Speed-Pro, about 10 years old. Rick L.

Totally understood. I'm just trying to get a feel for the graphs.

I've got my alpha N set up pretty linear right now. I need to add fuel more mid rage TPS and RPMs to eliminate the hesitation. I'm also trying to get the car on a dyno.

How do I reach Fred?

len

fkemmerer · #15 (**permalink**) 04-22-2009, 04:48 PM

Quote:

Originally Posted by kobrabytes

Totally understood. I'm just trying to get a feel for the graphs.

I've got my alpha N set up pretty linear right now. I need to add fuel more mid rage TPS and RPMs to eliminate the hesitation. I'm also trying to get the car on a dyno.

How do I reach Fred?

len

Len,

Hi. I am on this forum as Rick indicated in his post. I'm curious why you went to alpha-N vs. sticking with speed-density and solving your problems another way. Alpha-N is great on the drag strip where you run the motor at 2 setting - idle and WOT but its usually not the best choice (or necessary) for the street.

- Fred

kobrabytes · #16 (**permalink**) 04-24-2009, 10:09 AM

Quote:

Originally Posted by fkemmerer

Len,

Hi. I am on this forum as Rick indicated in his post. I'm curious why you went to alpha-N vs. sticking with speed-density and solving your problems another way. Alpha-N is great on the drag strip where you run the motor at 2 setting - idle and WOT but its usually not the best choice (or necessary) for the street.

- Fred

HI Fred,

In speed density the map sensor doesn't deal well with the low vacuum that I get off the TWM set up, around 6lbs at idle. The idle in SD mode was very eradic, the cursor never sat in a single cell. We even tried buffering the vacuum to no avail. Even with the throttle fully closed the computer would tell me that I was at 60% and always dump in fuel, lots of back fire on deceleration. Plugs continuously fouled. Here in SLC we are at a base altitude of 4500ft, I do drives up to and over 10k ft. Each trip was a guarantee to Checker that I'd be by for new plugs.

FAST says not to use speed density with less than 10 lbs of vacuum.

Currently I have the car running much better in Alpha N than it ever did in SD mode. No backfire and the idle is rock solid. Plugs stopped fouling.

I don't understand what you mean about two step? Idle is tuned really nicely on the first row. I have 15 other rows to define cruse and power...

fkemmerer · #17 (**permalink**) 04-28-2009, 08:40 AM

Len,

It your car is running better in Alpha-N mode, then by all means use it. Alpha-N has somewhat less adaptability to changes in barometric pressure and air temperature than a speed density setup would. The other tricky part of tuning with Alpha-N has to do will the large throttle blade area of most stack EFI setups. In many cases, the throttle bodies will reach maximum air flow at only part open settings below 3,000 RPM. This means that your pulse widths will reach their max values at TPS openings of 70-80% in the lower RPM ranges.

What is your camshaft like?

- Fred

kobrabytes · #18 (**permalink**) 04-28-2009, 05:15 PM

Cam 248/252 at 50 and 112 degree lobe separation.

fkemmerer · #19 (**permalink**) 04-29-2009, 09:26 AM

Your CAM is pretty close to what I have in my 482 FE (mine is 242/248 @0.050, 112 degree LSA, Lift is .645/.635in). My setup uses speed density mode and idles nicely at about 800 RPM. I was also at the 60% load point in my map at 800 ROM idle. I did use the timming trim feature to help get a smooth idle and my TWM intake has an IAC installed. Do you remember what your VE table setting was at idle in speed-density mode? Mine is at 26. Also, what is your motor's displacement again?

- Fred

kobrabytes · #20 (**permalink**) 04-29-2009, 07:36 PM

VE at idle was 35.

No IAC on mine...

I'm at 527 CI.