Thread: Installing PLOG on 99 GTP

I am installing a PLOG in my 99 GTP and when it's bolted on, the bottom corner of the PLOG contacts the A/C compressor. Is this normal? The engine is completely stock. It looks like that could heat up the A/C compressor and cause it to fail.

It does. Mines isn't touching the ac compressor at all

I removed the plog and ground down the top of the A/C compressor slightly. Now there is enough clearance to slip a piece of paper through. About 1/16" to 1/8". Attached are the pictures. The first one is infront of the car looking down at a mirror to see the clearance. The second and third are without the mirror.

I guess I can't post the pictures.

Tried to create a photobucket account but it is not working. Their web page is not working right. I did drive it and it doesn't seem to be making the A/C compressor hot. But it seemed to have an opposite affect with my knock retard. I had a high of 7.5 knock retard with the original manifold. After putting on the PLOG, it peaked out a 12.5 knock retard. It seems to have made things worse.

Thanks Bill. I just sent you an email with the three pictures.

Just an update. I also purchased the 3" SS downpipe and installed it today. I broke one of the bolts off that attaches it to the muffler and couldn't drill it out so I will have a muffler shop remove it tomorrow. But when I took it for a spin, I didn't have any knock retard at any speed. When I tried it out with just the PLOG, it was getting high knock retard. The PLOG so far doesn't seem to heat the A/C comressor up, since I ground down enough of the compressor that it's not touching.

After seeing this, I went and looked at my Plog as well and it is very damm close to the Compressor, not hitting since I could still bolt it on fine but I wouldnt be surprised if there is 1-4mm of clearance between at most..

Carlos, that's about exactly the same as mine. Have you noticed if it heats your A/C compressor up any?

Originally Posted by Carlos773

After seeing this, I went and looked at my Plog as well and it is very damm close to the Compressor, not hitting since I could still bolt it on fine but I wouldnt be surprised if there is 1-4mm of clearance between at most..

couldnt it in theory be hitting your ac compressor then when the motor rocks causing a possible false KR? Also why do people even buy powerlogs? Its like 50 bucks more to get cheap headers and a lot more performance..

Max,

Both the A/C compressor and the exhaust manifolds are attached to the engine block, so they should both move togther when the engine rocks. The reason I chose the powerlog is because I knew I could intall it and the downpipe myself. I would have to pay someone to install headers making them more expensive. The "lot more performance" is debatable for those who don't plan on doing much more modifications. If I felt comfortable doing the headers myself, I definately would have gone that route.

Originally Posted by Max Cook

couldnt it in theory be hitting your ac compressor then when the motor rocks causing a possible false KR? Also why do people even buy powerlogs? Its like 50 bucks more to get cheap headers and a lot more performance..

Originally Posted by 99GTPMLA

Max,

Both the A/C compressor and the exhaust manifolds are attached to the engine block, so they should both move togther when the engine rocks. The reason I chose the powerlog is because I knew I could intall it and the downpipe myself. I would have to pay someone to install headers making them more expensive. The "lot more performance" is debatable for those who don't plan on doing much more modifications. If I felt comfortable doing the headers myself, I definately would have gone that route.

oh yeah duh lol dunno why I didnt think about that haha.

The reason for the purchase for me was the black friday deal that went on, and my crazy plans of turboing it that I have decided against for now. I will be going headers in the next few weeks.

As for the plog, I will check today in a little bit, my father is using the garage at the moment.