New mechanical speedometer drive solution
Teching In
Joined: Nov 2011
Posts: 29
Likes: 0
From: Chambana, IL
@51caddyman to clarify, the device takes the input from the VSS as gospel. But if you change tire size or rearend gear without telling the onboard ECM, the speed reported by the VSS to the speedo driver will be wrong. And it will happily drive the needle to that spot, which will be wrong, off, annoying LOL. However, it does give me stuff to think about when designing the next piece, which was asked for by the carbeureted guys. It'll be a reluctor ring and pickup for guys without the ECM/VSS. Basically it'll be our own VSS. Giving it a slick way for all y'all to enter tire size and rearend gear ratio on the fly recalibrate would seem to be in order.
Registered User
Joined: Jun 2012
Posts: 5
Likes: 0
From: Broomfield, CO
That sounds great... The other option I've been looking at is adding a 90-92 Chevy DRAC in line between the VSS and the "zipster" unit, with a dip switch mod, I should be able to make up for those gear ratio changes and seeing my 89 ECU doesn't need the input from the VSS (as that was all done on the speedo itself for that year) I don't have to wire that into the ECU itself, as far as I've gathered in my latest round of research. This also might work for anyone with those "in between" transmissions (plus the Zipster Speedo mod), but I still need to do more reading on this suject. Quote: "Digital Ration Adapter Controller (DRAC) and Vehicle Speed Sensor Buffer (VSSB) are both electronic devices that simply convert the input AC signal (from the VSS) to a calibrated digital DC signal. The DRAC sends 2,000 digital pulses per mile to the ECM (or in my case the Zipster unit), 4,000 digital pulses per mile to the cruise control module (N/A for now, but that would be nice later), and 128,000 digital pulses per mile to the ABS (yea, no need to hook that wire up) computer. The DRAC and VSSB units are pre-calibrated from the factory according to the vehicle's stock gear ratio, and tire size. But, it can be re-calibrated by simply moving jumpers around." from: http://www.tbichips.com/drac/
Teching In
Joined: Nov 2011
Posts: 29
Likes: 0
From: Chambana, IL
Their digital gauges are nice. Enjoy. Sorry we couldn't get it out fast enough for you Leon. But I'll eat my investment in this project before I ship something that isn't worth installing. If anyone else needs something right now or you're going to melt, DO NOT WAIT for me to finish. If you're on a deadline, get something else. Go to Dakota or AutoMeter or the scrapyard. I can not promise when or if this thing will pass beta QA and/or become available. I wish I could (since actually none of you could possibly be as impatient as I am to release this thing), but I can't.
Registered User
Joined: Jun 2012
Posts: 5
Likes: 0
From: Broomfield, CO
Speaking of Dakota Digital i found they sell a unit called the SGI-5 -It's basicly a DRAC with the dip-swtich mod in a pretty package for $75 (from Summit). That would be a perfect in-line between the VSS and the Zipster/Invader unit for those of us looking to swap ratios or tires and can't mod it on the PCM. There is something to be said about a new part... I had to zip tie my brake light switch lever arm to my brake pedal arm yesterday to drive home from work, after 61 years the spring finally let go... As for the speedo in the mean time, i just bought a 200W power inverter, installed it behind my dash and ran my cell phone power cord out of my clock hole (I know, that sounds very dirty, but its a big nice hole in my dash from that old 6V clock). Then i just put some velcro on my phone and the support bar in my speedo cluster hole; now I can see how fast i'm going and won't BBQ my phone battery in 15 mins. I love the fact that you won't release an "early" product just because we are badgering you for it!!! That is what makes a great product vs. all the crap out there (cable-X); pride in a job done right, not just in it for the $'s! Stick to it Zipster/Invader; I'll be waiting for you!
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Speaking of Dakota Digital i found they sell a unit called the SGI-5 -It's basicly a DRAC with the dip-swtich mod in a pretty package for $75 (from Summit). That would be a perfect in-line between the VSS and the Zipster/Invader unit for those of us looking to swap ratios or tires and can't mod it on the PCM. There is something to be said about a new part... I had to zip tie my brake light switch lever arm to my brake pedal arm yesterday to drive home from work, after 61 years the spring finally let go... As for the speedo in the mean time, i just bought a 200W power inverter, installed it behind my dash and ran my cell phone power cord out of my clock hole (I know, that sounds very dirty, but its a big nice hole in my dash from that old 6V clock). Then i just put some velcro on my phone and the support bar in my speedo cluster hole; now I can see how fast i'm going and won't BBQ my phone battery in 15 mins. I love the fact that you won't release an "early" product just because we are badgering you for it!!! That is what makes a great product vs. all the crap out there (cable-X); pride in a job done right, not just in it for the $'s! Stick to it Zipster/Invader; I'll be waiting for you!
TECH Apprentice
Joined: May 2006
Posts: 360
Likes: 1
From: Kansas City metro area
Very interested, subscribed. I don't want to muddy the waters but when you are comfortable maybe you could look at a box to make old tachs work with the LSx PCM? I have a schematic and the guy that posted it said anyone was free to make it, but my soldering and electronic fab skills are zero. The components are under $10. Maybe another product to think about?
Very interested, subscribed. I don't want to muddy the waters but when you are comfortable maybe you could look at a box to make old tachs work with the LSx PCM? I have a schematic and the guy that posted it said anyone was free to make it, but my soldering and electronic fab skills are zero. The components are under $10. Maybe another product to think about?
Teching In
Joined: May 2012
Posts: 5
Likes: 0
From: North Florida
Hi Zipster, I waited for over two years for the SpeedChanger Mechanical from Terf inc. in Michigan. Matt told me twice that he would have it ready in a couple of months, so I waited (2.5 years now). I have a GPS that gives me my speed and much more now, but I want my original speedo in the 55 Belair wagon to work again. I will wait for you to get this done, but is there any way that all of us who are waiting could get notified. I check this site at least once a week but if I forget for a couple of weeks or a month I would hate to find out that you completed this project and they were all sold out. I got a nasty response (not from you) when asked if there could be a waiting list for potential customers a month or so ago. But I see several others are waiting as well, so I will continue to follow your progress and hope to be on any early order list if that happens. Thanks, LAkers
TECH Apprentice
Joined: May 2006
Posts: 360
Likes: 1
From: Kansas City metro area
It is an older Sun Super Tach but not with the remote box like in the '60s. The design the guy showed has a couple of ICs, some resisters, and a capacitor. He is over on LS1tech.com and says it works great.
