Shh, my wife thinks my 3.4L coversion will only cost $2,500 (LoL)

[jungspike]

I have a mostly stock 1984 Targa that is driven primarily on the street, but also Autocrossed and DE-ed with 105,000 miles. Yes, I know I could improve my times cheaper by buying a newer care, installing a newer engine and/or getting more seat time, but this sounded more fun….

Two years ago, when reading the local PCA mag, I came across a 911 “hop-up” kit of used parts. It consisted of: 98mm Mahle pistons (no cylinders), 20/21 cams, honed intakes, matched injectors, Autothority MAF, Bursch headers, B&B racing muffler, SW chip, short shifter and other misc parts for $2,700. The parts were very lightly used before the PO decided to go “bigger and better.” I never intended to modify my engine, but I did have a secret list of parts I would put in my car if I won the lottery… and this kit had everything--so I bought it.

Before I started the mods, I dyno-ed my car. Unfortunately, I think the dyno wasn’t very accurate because it gave me 245 BHP (corrected to Seal Level) on a stock 3.2L engine (with Autothority chip). I put on the Autothority MAF. It took just a couple minutes, and then, I took it for a ride. I could barely sense a difference. I am sure glad I did not pay $2,000 for that thing new. Next, the new intake went in. It took me about a about a weekend. Time for another test drive—boy what a difference!!! I noticed better throttle response. I am not sure what the HP gains it made, but I was so happy and proud of doing the work myself. The pistons and cams would have to wait two years.

After returning from a deployment to Afghanistan this fall, my wife and I decided that I earned it… I told her it would cost about $2,500--about $1,000 for boring of the cylinders, $1,000 in labor and $500 for misc. Right? After all, I had most of the parts! OK, maybe not. I have done (almost) all the work on my car for the last 11 years, but I thought the engine overhaul was a little beyond my capabilities, so I went back to the shop where I bought the parts and asked them to install them. I am also slightly sad that I did not tackle this job myself, but am also glad that the engine will be done by a professional.

My mechanic dropped the engine and then made the following suggestions: replacing the rod bearings, the exhaust head studs, valve guides, etc. He will not split the case. And the classic line, “While you are in there, you mind as well…” In my case, I mind as well replace the clutch and put in an aluminum pressure plate. So, now I am up to $4,500-ish. (ssh-My wife still thinks it is $2,500… she will never read this post right?)... And I still need to buy a muffler, because that B&B is not meant for the street and it would be a shame to restrict the engine with the stock exhaust.

Anyway, it will be ready around March. I can’t wait. I read the Pelican forums and search the Pelican classifieds daily, hoping to find more used parts to keep the cost down. So, I thought I would share this with you.

[Spenny_b]

Haha, welcome! Sounds like a good project. Think of the other upsides to getting a shop to do the work;

1) it's less likely to "scope creep" when you're not sitting in front of it with a mug of tea (or bottle of beer) in hand, doing that midnight pondering

2) it's more likely to get done in a reasonable timeframe and less subject to domestic distractions.

When do you reckon it'll be on the road then?

Re exhausts, have a look at ALEX P's 964 engine rebuild thread...last page, Alex is considering swapping his headers for something different. No idea if these would be suitable for your build, and no idea where Alex is at with making a decision with his (hopefully I'm not speaking out of turn...) but you never know, there *may* be a conversation to be had?

[jungspike]

Spencer,

Yes, there are advantages to having a shop do the work. They have already found a couple things I would have overlooked. I should have the car back in late March.

I looked at Alex's post--he is struggling with exhaust system choice like me. Headers are lighter and give a small power advantage, but the heat exchangers with the stock system is valuable to me in Colorado. I have the headers sitting in my garage, so I just have to decide to buy a 2-in muffler for the headers or a new pre-muffler and 1-in sport muffler for my stock system. Of course the stock system will also pass a smog check. The question is how much HP gain do you get with the headers (mine are 1-5/8" inside diameter). I posted that question on Rennlist and most said that the headers would be best, but since I am up at 5,000+ ft, I am not sure--is it 20 HP? I doubt it is more than that. I might buy both and then sell the looser on the Pelican Classifieds. As for brands, I plan on going with M&K.

I looked at your engine posts--quite a nice looking car, and a great story.

Thanks for the support,
Tim

[Jcslocum]

Here a a couple of my thoughts:

Headers are nice if you can make heat exchangers for them. You can run the 993 HX and adapt a muffler to it. We have done this recently for a 3.6 install in place of a 3.2. We did it with the round flanged HX but I think the oval would have been easier. More pipe to work with.

While the heads are off, have them twin plugged, even if you don't use them right away. You can just run a dead plug in the hole but if you ever want to twin plug and boost the compression, you have the heads done and all you have to do is add ignition. It's not a huge increase in cost and can save you lots down the road.

I think a 3.4, depending on compression will need the twin plug ignition. This is what we are doing on our 3.2. We are looking for 10.5:1 or so, so the 2x plugs are needed at this comp ratio.

[jungspike]

Thanks Jon, your post pushed me over the edge to do the twin plug machining. I'll leave dummy plugs in there for now. My pistons are supposed to be only 9.8:1 and since I am living in Colorado I am not too concerned about detonation, but it should be about $400-ish now, so why not!?

... and I am going to keep an eye on Pelican and Ebay for some 993 headers.

Tim

[Jcslocum]

Tim, the 993 isn't s straight bolt on install. The flanges need to be turned on one side. Instant-G has them all ready to go.

[dmark9]

Hi Jungspike,

Thank you for serving our country, you've have earned this for sure.

Let me know if I can help with any questions. I just rebuilt my 964 motor and sent out my fuel injectors to be sonically cleaned and have the before/after numbers to show the difference. Did a lot of other stuff to and was surprised at how much prices can vary on simple things like powder coating.

Good luck,
dmark9
P Fix It | Porsche 964 | Repair & Maintenance Videos

[jungspike]

Thanks dmark9,

My engine is almost done & I just bought a M&K muffler, so I should have it back it about a month.

Tim

[jungspike]

Got my car back this weekend. Total cost $8,100. $2,000 in labor, the rest in parts. Included: 98mm Mahle pistons (used), bored cylinders, GT2 cams (used), 930 valve guides, new timing chains & sliders, APR rod bolts, new rod bearings, steel head studs, new fuel pump, Bursch headers (used) , M&K 2-in 1-out muffler (used), aluminum pressure plate (used). Honed/polished intakes (used), matched injectors, Autothority Mass Flow Sensor (used), Steve Wong chip (used). The case was not split. Things I would have done if I had more $$$--1) Twin plug, 2) Racing valve springs. I love the exhaust note. Whoever says M&Ks are too loud are crazy! It sounds great, but I can still have conversation when cruising at 3,000 RPMS. Here are some videos so you can hear for yourself. I will get the car dyno-ed after break-in.

MOV950111 - YouTube

Porsche 911 Carrera with M&K 2-in 1-out muffler - YouTube

MOV956422 - YouTube

MOV952775 - YouTube