Might get off my lazy butt, would like opinions of a couple products.

[mmb617]

As we all know time flies and stuff you intended to do somehow gets put off for years. There are two things I've wanted for my car but never got around to doing and I'm thinking maybe it's time to get to work.

When I was racing every week I was always working on my car and maybe I got a bit burnt out because I quit racing after the 2014 season and haven't done much of anything with my car since. I do still like to take it for a drive on nice days but it's time to address two issues that bug me.

The car has power brakes and since it makes virtually no vacuum at idle the brakes suck under that condition. I'd like to convert to manual brakes and have had this setup bookmarked for years. Anyone who has used it, please comment.

https://skinnykidracecars.com/produc...-light-switch/

The second issue is gas mileage. Granted it's a 408 and the cam has a lot of overlap so it's not going to deliver great gas mileage but it's presently in single digits just putt-putting around town and that's not acceptable. I'm running a Holley 4150 carb and it's still jetted for it's best performance in the 1/4 mile. In order to have some meaningful feedback while rejetting I'd like to install a wideband gauge which should be easy as I already have the bungs capped off in my headers. This is what I'm looking at and if you have one let me know what you think.


https://www.summitracing.com/parts/inn-3924

[mudgepondexpress]

Did you retain power steering? If so have you considered the hydroboost off a 2004ish Mustang? That is the route I am going to take. Smaller unit, consistent assist. I drove too many cars with manual brakes in my life, they make it no fun to drive.

Kenny

[mmb617]

I converted to manual steering years ago as I wanted less steering input on the top end. I was quite happy with that conversion as with my skinny front wheels it's still easy to steer at parking lot speeds yet it's more stable at speeding ticket speeds.

I grew up driving cars with manual brakes, and drums on all four corners no less, so I can't imagine manual brakes on a light car like mine would present any problems. When I was racing I was always reading about how crappy the stock fox body brakes were yet I never had any problem hauling my car down from 118 mph, so maybe my expectations are low.

When engine vacuum is high my present brakes work fine, but when I back the car out of the garage down a slight incline with the engine idling there is very little braking power unless I heel and toe it to bring the revs up. That's what I want to fix. A side benefit would be that eliminating the big vacuum booster would make it easier to work on the left rear of the engine that the booster presently overhangs.

I'm pretty much set on the manual brake conversion, but I would like to hear from anyone who may have used the Skinny Kid brand.

[OX1]

I have that A/F and it works fine. I've read tuning a CARB with an A/F is very frustrating, especially idle.
No matter how many times you tune it, it constantly changes.

[Ken P]

There are also secondary vacuum cannisters that you can install to serve as a back up for the brakes. Simple set up with a couple of check valves and the lines.

[mmb617]

There are also secondary vacuum cannisters that you can install to serve as a back up for the brakes. Simple set up with a couple of check valves and the lines.

Thanks for that suggestion. I hadn't realized such a thing existed. You mean something like this?


https://www.amazon.com/JEGS-63011-Va...6147890&sr=8-2


The description makes it sound like just what I need as it's designed to make up for the low vacuum condition caused by big overlap cams, which is my problem exactly. The only time I notice a lack of braking is when the engine is at idle, so perhaps this is all that's needed.

[mmb617]

I have that A/F and it works fine. I've read tuning a CARB with an A/F is very frustrating, especially idle.
No matter how many times you tune it, it constantly changes.

Good to hear you have that one and it's working well. When researching I kept coming across comments from people who were very dissatisfied with the AEM one but I didn't read anything bad about the Innovate unit. It's still better to hear from someone I know is giving me the straight scoop though. That's mainly why I posted this here.

I'm not real concerned with getting the idle mixture perfect but I'm sure I need to run smaller primary jets. I want to be able to monitor the A/F so I don't end up going too lean and damaging the motor. My hearing is poor and the car is loud so I don't know if I'd notice a pre-ignition knock were it to occur.

[Greywolf]

I've run the Innovate LM-1 and LC-1 on other various projects about 10 years ago. Good products and good service and if I needed an a/f monitor today I'd look at that one for sure.

That canister might be the answer to your problems (and a lot less work to install than a manual conversion!), but you still need enough vacuum to make it work. Also check the check valve on your brake booster.

If you want to try a cheaper option than that shiny one, look at the plastic vacuum canister from a 1991-1996 Jeep Cherokee 4.0 (around $10 new online), a brake booster check valve, and a hose barb. Way less than half the price, especially if you have the check valve, hose barb and some hose in your parts bin.

[Ken P]

Thanks for that suggestion. I hadn't realized such a thing existed. You mean something like this?


https://www.amazon.com/JEGS-63011-Va...6147890&sr=8-2


The description makes it sound like just what I need as it's designed to make up for the low vacuum condition caused by big overlap cams, which is my problem exactly. The only time I notice a lack of braking is when the engine is at idle, so perhaps this is all that's needed.

Yes that is basically the same that I have / had somewhere in my garage. Except mine was just painted black. Someday if I ever get around to finishing my 66 fastback I will need it for sure.

Every time you get on and off the gas while cruising it will build and hold vacuum.

[boboli]

Or maybe get a vacuum pump from a 2000's s40/ v50 Volvo at the junkyard and wire it up. then you would have power brakes. Seems like a lot of new cars don't rely on engine vacuum any more. they just have an electric pump to provide the necessary vacuum. Gm has a similar pump. I don't know the applications but I'm sure it would be easy to find out

[mmb617]

Thanks to all for your suggestions. I went ahead and ordered the Innovate A/F gauge and a vacuum canister from Summit yesterday and they are scheduled to arrive today. At some point I'll check back in and let you know what I think of both products.

[Ken P]

I figured out where my canister is located. I had installed it as a back up for the vacuum windshield wipers on my 55 Jeep. It worked OK for a while but then they came out with the electric motor kit.

I tried to add a pic but I'm getting the "Over my limit" message again. That happened a few years ago and never could figure out how to delete ancient pics. Oh well...

[mmb617]

This is the vacuum canister that I bought. It's a very nice looking unit but a little bigger than I had visualized. I haven't figured out where I'm going to mount it yet.


https://www.summitracing.com/parts/cca-5201

[OX1]

Good to hear you have that one and it's working well. When researching I kept coming across comments from people who were very dissatisfied with the AEM one but I didn't read anything bad about the Innovate unit. It's still better to hear from someone I know is giving me the straight scoop though. That's mainly why I posted this here.

I'm not real concerned with getting the idle mixture perfect but I'm sure I need to run smaller primary jets. I want to be able to monitor the A/F so I don't end up going too lean and damaging the motor. My hearing is poor and the car is loud so I don't know if I'd notice a pre-ignition knock were it to occur.

I have 3 of the AEM also. I was always curious about how close they were, so I tested it on my Capri.
Datalogging they were mostly within .2 tenths of each other. AEM starts reading faster on dead cold start,
as Inv takes some time to heat up. Inv seems to smooth the curve better, not changing as drastically from entry to
entry on datalogging, but not sure that matters much, each entry is .062 seconds from the next.

Also, actual A/F @ idle and cruise on injected cars bounces around so much, upwards of a point in A/F, hard
to guage exactly what it is doing on each datalog entry. Would be cool to see a datalog from a carbed car
where computer is not trying to adjust constantly.

Both widebands and stock O2 in my 3" downpipe.





Cold startup (rich) vid here......

http://luxjo.supermotors.net/CAPRI/E...721_121127.mp4

(vid is 38 Mg, might need to click on 3 dots that come up and download to watch, WIN 10 is a PIA about it sometimes).

[mmb617]

I got both the vacuum canister and the wideband installed, so I took the car for a short drive to get an idea how they were going to work for me.

The vacuum canister does help some with braking while the engine is at idle. I can't say it's a huge difference but I'll take what I can get. The brakes feel fine in normal driving but that wasn't a problem before either. For the $75 or so the install cost me I'd say it was worthwhile.

The wideband readings fluctuate a fair amount but looked pretty good at idle once the car was warmed up. I kind of expected that as I'd originally set the idle mixture using the highest vacuum reading method. The main reason I got the wideband was so I could jet the primaries down from what I was using for racing, and sure enough the readings indicated I was pretty rich while accelerating or cruising. I made a pretty big change going from #72 jets down to #68 and the readings look pretty good there so far. I need some longer drives to monitor them better and might have to hook up my laptop for some data logging to put the information in more usable form. I mainly wanted to see the readings to confirm what I was already pretty sure of, that I was way rich and could make a significant change in jetting.

I'll be interested to see how much difference the jet change makes in fuel mileage which was about 10 mpg in around town cruising. I'm sure I could really help that if I made a cam change but that's not going to happen. One of the things I like most about the car is it's sound at idle. I'm willing to pay for that as it takes me back to my youth. Cam lope has always gotten me excited.

[795.0pacecar]

I found this article on adding a vacuum pump, I haven't done it but it looks like a good and inexpensive remedy.

https://www.streetmusclemag.com/tech...acuum-booster/