Aftermarket gauge install

[MBuck951]

My mounting panel finallly arrive from Lindsey Racing and i'm ready to put in a VDO boost gauge a friend gave me. Previously it was in his Supra TT, where the install was as simple as tapping a vaccum line with a T. Now its going in my car, so I can get a more accurate baseline.

Is it this simple with our cars and more importantly which line did you tap? Pictures please!

thanks

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Mike Buck
My Gallery
'88 944 turbo
'89 944 NA

[seb928s]

I would use the vaccum line that is in the passagers footwell or whatever it is called there is a vaccum line there just T the vaccum line and feed the line to where you are going to mount the gauge at. It will be more accurate then the stock one for sure. That is the easiest way to install the gauge. Don't know what others do it but I'm getting a gauge soon and I'm doing it that way. So if any of you guys think that is bad then tell us.

[wolfrpi]

You have to do a T in that hard clear plastic line in the passender footwell. I bought the Brass T at Ace hardware and it worked fine.

Erick

[MBuck951]

I take it there is only one clear line to look for? Tapping here won't disable the stock gauge will it?

I'm checking my car right now

thanks again

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Mike Buck
My Gallery
'88 944 turbo
'89 944 NA

[seb928s]

Not if you use a T. It then goes to your aftermarket gauge and the stock gauge nothing can go wrong.

[phoenix_iii]

Pics?

[Pete R]

Lindey Racing has directions with pics on their site. Under the tech session there's directions for most of their product. BOOST SUPPLY FOR GAUGE at LINDSEY RACING - Your Porsche Performance Parts Center

[phoenix_iii]

Great! Thanks Pete!

Now to look into gauges (manual vs. electric), and where/how to mount (should be an easy enough search!)

[phoenix_iii]

How can you tell what switched power is vs. not, in the fuse box? (without testing each spot)?

Also, what about illumination, how did you guys handle that (for switched/night time).

Thank you,

[Techno Duck]

Switched 12v comes on with the key. The usual source for that is tapping off the switched 12v wire for the radio.

For illumination, the most common place is tapping into the ash tray light.

[phoenix_iii]

I was just thinking, can't I get the 12v wire from radio, the switched from the radio too, and the ground?

I don't even know if my radio (or the 951 harness) has an illumination wire (well, I know the radio does, I found the pin out). Does the 951 have a radio illumination wire? Any reason why I should both Mr. Ashtray for anything?

If I have to, which wire is it on the ashtray? =) Thanks TD.

[Bonestock951S]

If you use the ash try light as a power source, it will be switched on with the headlight switch and also dim with the dimmer.

[phoenix_iii]

I took 12v from the big red ignition on for the Radio +12V
I took accessory switched power from the Ash tray light (the loom actually goes all the way back to the radio. I feel bad because I cut the ash tray light (I HATE modifying OEM wiring, but the bulb was not installed for years it seems, and it looks like it's because one of the wires (Purple if I recall) is dead.
I took ground from the ash tray light loom too.

This was a 4 wire Prosport White/Amber Boost/Vacuum Gauge. From that gauge, it has black (go to ground), red (twist with white) to the 12V red from the radio (spliced into Radio harness, not OEM wiring), and amber, into the 'blue' (faded bad) line from the ashtray. White was twisted to red, and both went to the red 'Power' for the radio.

So it works great. I didn't even check to see if it works with the dimmer, but it might!! Didn't feel like getting the Cig lighter involved, too cold outside (I live in an apartment, blah).

[choinga]

if you really want to do this right, run a long line from your gauge up under the glove box (you'll probably have to take the part that opens off, but it's easy) and splice it in close to the intake. I bought a custom piece from Laust Pederson on Rennlist that gives you 5 nipples where the KLR banjo attaches to the intake manifold - or you could get a 4 port banjo from Lindsey racing so that you are getting the most accurate reading possible - directly from the intake - and more importantly not chopping in to that KLR line.

And once again, if you really want to do this right - don't run your 12v from your radio - run it and your ground directly into the DME harness. Easy to find the pinout's (there are several 12v and ground wires to choose from). Just splice in and solder to one of those.

It's easy to jimmy this kind of stuff and then you end up back in there fixing it again. Do it right the first time.

[phoenix_iii]

I am using proper wiring techniques concerning the fittings.

WRT splicing into the KLR line, that is unfortunately what I have to do now, in the short term. Lindsey even has instructions on how to do this, so it much be marginally acceptable. Thank you for your input though, choinga! =)

[Bonestock951S]

I do not see any problem with splicing into the KLR line. It is a single dedicated line, without other devices drawing off of it.

RE: Wiring, I would be somewhat hesitant to splice directly into the DME wiring. If you get a cold solder joint there, that would make for a not so fun day.

[choinga]

that will all work, of course. I'm just saying - if you want to do it right...

I have a Vitesse piggyback and MAP that I wired into the DME...probably something like 15 splices in all...and I hadn't soldered a joint in almost 20 years since I was in the military. It ain't rocket science and a cold solder joint is easy to fix. Just practice a few before you get in there and make sure your iron is hot.

I just don't trust the birds nest in any car that's jammed in behind the radio. It will most likely be fine but a boost gauge isn't something that you are going to remove...probably ever. So, once again - my money is on taking a few extra minutes and doing it the best way possible and not destroying other stuff that's working fine to save a little time...

Just my .02...

[phoenix_iii]

Well then I am glad I didn't destroy anything that was working fine then. =)

[Bonestock951S]

Using a power source other than the DME is not going to ruin anything. I used the ash tray light for 4 years without issue and retained the functionality of the ash tray light. My point was that he is wiring in a gauge, not an engine management system. Using the DME over the ash tray light isn't doing it the right way over the wrong way. Either way is fine so long as the install is done correctly. I can see why you would wire in a MAP and piggyback, probably much like I installed my TecGT.