Incremental upgrades- ideas, options, help

[yorkemike]

Like most people I don't have an endless budget to do what I'd like to do to my car so I'm looking at this as an extended process of upgrades.
I guess I'll start with what I have, it's a 1979 911 SC factory sunroof delete car that has had a widebody conversion done with 139k miles on the clock. It appears to have been done well to my eye and still has the stock 3.0 litre in it with CIS, backdated SSI's and some sort of 2 in 2 out exhaust. It's running well now and like everyone I'd like to squeeze just a bit more power out of it. Recently had compression and leak down test performed on it and here are those numbers.
Compression Cyl #1 150 #2 130 #3 140 #4 150 #5 150 #6 150
Leak down Cyl #1 2.5% #2 4% #3 2.5% #4 2.5% #5 4% #6 5%
What I think I want is to do the cams(Webcams 20/21 or DC?), switch to Al's ITB/efi and up displacement to a 3.2SS configuration. Problem, as always, is how to I get there without the money required to do it all at once. I need a cam choice that will give me hopefully a little boost right away and continue to work with the CIS until the switch to efi because I'm thinking that's what i'll do first and then still work going forward with the rest of my upgrades. Next upgrade would be the efi and then ultimately down the road do the engine.
Hoping someone can help a guy navigate these murky and deep waters. Any and all suggestions will be appreciated at this point.
Thanks
Mike

[yorkemike]

Here's a couple pictures of the car, maybe someone can identify which exhaust this is too.
Mike

[darrin]

think you'd need to drop the engine and get pretty far into the heads to swap out the cams -- and then the cams would come right back out when you do the top end/engine.

Given your good compression/leakdown numbers (presume your oil consumption's good too?), best bet might be to bankroll money until you can do all of this at once -- that way, your cam/etc. choices wouldn't be compromised by the limitations to the CIS system you're also looking to replace.

To ID your muffler, we'd need a pic of the muffler itself (i.e. more than the pipes) -- nice looking SC!

[tmaull]

Yeah there’s not really a good reason to do this piecemeal. I’d enjoy the car as is until you’re ready to do it all. Looks awesome.

[AG81]

I have spoken to a number of respected Porsche engine builders and I agree with darrin. My engine is similar in miles and compression/leakdown numbers.

I want ITB's bad. But I am going to wait till the motor really needs attention and spend frivolously then......

[msmall215]

You're somewhat limited in cam choices for as long as you stick with the CIS style pistons. I have an '83 RoW SC and only changed the induction from CIS to Al's X-faktory Triumph kit (had SSIs and sport muffler), and I netted about 30ish hp gain across the board and about 25 lb ft of torque, so if you go just EFI/ITB now, you should see a nice bump. If your plans include a full rebuild and bump to 3.2SS down the road, I would wait til then to choose your cam as you'll have more choices with the new pistons.

[786]

save up and do all at once, car looks awesome btw!

[yorkemike]

Originally Posted by darrin

think you'd need to drop the engine and get pretty far into the heads to swap out the cams -- and then the cams would come right back out when you do the top end/engine.

Given your good compression/leakdown numbers (presume your oil consumption's good too?), best bet might be to bankroll money until you can do all of this at once -- that way, your cam/etc. choices wouldn't be compromised by the limitations to the CIS system you're also looking to replace.

To ID your muffler, we'd need a pic of the muffler itself (i.e. more than the pipes) -- nice looking SC!

Thanks for the compliment on the car! I will try to get a few pictures of the exhaust over the weekend.

[yorkemike]

Originally Posted by darrin

think you'd need to drop the engine and get pretty far into the heads to swap out the cams -- and then the cams would come right back out when you do the top end/engine.

Given your good compression/leakdown numbers (presume your oil consumption's good too?), best bet might be to bankroll money until you can do all of this at once -- that way, your cam/etc. choices wouldn't be compromised by the limitations to the CIS system you're also looking to replace.

To ID your muffler, we'd need a pic of the muffler itself (i.e. more than the pipes) -- nice looking SC!

Originally Posted by msmall215

You're somewhat limited in cam choices for as long as you stick with the CIS style pistons. I have an '83 RoW SC and only changed the induction from CIS to Al's X-faktory Triumph kit (had SSIs and sport muffler), and I netted about 30ish hp gain across the board and about 25 lb ft of torque, so if you go just EFI/ITB now, you should see a nice bump. If your plans include a full rebuild and bump to 3.2SS down the road, I would wait til then to choose your cam as you'll have more choices with the new pistons.

Maybe the ITB's will go to the front of the upgrade line then and do the rest later. Getting around 30hp would make me happy and I want them in a bad way anyhow!

[yorkemike]

Originally Posted by tmaull

Yeah there’s not really a good reason to do this piecemeal. I’d enjoy the car as is until you’re ready to do it all. Looks awesome.

Thanks!

[yorkemike]

Originally Posted by 786

save up and do all at once, car looks awesome btw!

Thank you!

[Josh D]

I've been buying and stashing parts to take my SC out to a 3.2ss for a few years now. I have all the parts, now it's pretty much down to just pulling the motor and getting the heads, flywheel, rocker shafts and cams to the machinists to get redone and getting it back together. It's the mental block of knowing my car will be down for awhile that keeps me from doing it! I drive less in the summer due to the AZ heat, so maybe this spring I'll have the courage....

[Mothy]

Unless you are wanting to just focus on the engine for a reason, I'd suggest the best incremental approach is in other areas.

Suspension
torsion bars can be upgraded
shocks can be revalved to match
sway bars can be increased to Carrera size or buy adjustable ones.

Brakes
changing to Carrera Brakes gives more heat capacity
good pads
can even go to Boxter front with Carrera back - good balance without going over the top.

Weight
already a good start without the sun-roof weight up high
other items can be deleted to reduce the weight
light weight can also be as good as a mild increase in HP.

Importantly you can doo all this in stages, and its all reversible back to standard.

Tim

[chrismorse]

Mothey and Yorkemike have some good points.
I'm going through my 74 now, with a bone stock 2.7 engine my dad went through 10k miles ago. Full brake and suspension overhaul, quick rack, recovered sport seats, duck tail, Carreras cooler.
Seems a shame to do cams and P&Cs on a good running engine.
I'm seriously considering Al's PMO EFI for the slight bump in hp, but more for the better throttle response and better sound. I know I will have to duplicate a lot of the efi and ignition tuning but I cannot afford to do it all now.
I am also looking at a BIG chunk to go through the tranny, synchros, bearings, Guard LSD, Wevo gate, new R&P +++
Gotta get this done before I croak.
Chris

[yorkemike]

Here's a couple of pics of the exhaust. Kinda hard to get up under there without a lift and laying on the floor in freezing temps up here in the great white north.

As a few have noted, losing some weight is definitely happening as well. I've deleted the rear seats, plan on doing RS door panels, removing center console and will also be getting a lightweight battery. Got some new seats too but I want to get them recovered with hounds tooth inserts before sticking them in. Trans is in good shape as it was rebuilt a few years ago by a previous owner so that's not a worry at this point but might get a Wevo shifter.
Perhaps these change plus the ITB/efi will get me what I'm looking for, for the time being. As Chris said I'd love the throttle response and especially the sound of those out back. My exhaust, whatever it is, sounds amazing while running WOT.

[David 23]

Follow the excellent advice you have been given here. Do all the engine mods at one time, I finished the conversion from a stock 3.0 to a hot twin plug 3.2SS with RSR high butterflies and EFI last year, and it is clear how everything is related, and piecemeal improvements are simply impractical.
I second the suggestion to focus on suspension and weight reduction. While perhaps not as exciting, it makes the biggest difference in your actual feel and enjoyment of the car. You simply will not believe what the reduction of a couple hundred pounds, combined with suspension improvements will do the the nature of the car. To me, the muffler appears to be an M&K.

[ClickClickBoom]

Originally Posted by yorkemike

Thanks for the compliment on the car! I will try to get a few pictures of the exhaust over the weekend.

Looks very M&K:
RarlyL8 EXHAUST SYSTEMS FOR YOUR 911

[porschenut]

If you simply change your gear ratios and pop in a 7:31 RnP you can save 75% of the cost and 75% of the time, and end up with the same result as all of the expensive engine modifications you're talking about.

[jpnovak]

Don't touch the engine.

As said before. Sort the suspension first. Bring it all up to good standard and upgrade depending on road conditions and driving style. Then make sure to get good corner balance and alignment.

Then some type of sport seats so that you can stay in place while enjoying the new suspension.

Then get some driving instruction so that you can maximize the capability of the driver and the car together.

Once you can exceed the car limits go for more power.

[MichaelSJackson]

Lots of good advice, but I'd follow jpnovak's closely.

I have a white SC too. For myself, I've discovered it's a good idea figure out what your long term goal is. Some here are headed toward a track car, some a canyon carver, others a nicer daily driver. This advice doesn't just apply to the engine, but to the suspension, brakes and even the interior.

You already have a very nice car. Best bang for the buck is to improve the driver. Take instructions through PCA or one of the schools. This will also help you discover your goals.

It doesn't make sense to replace the cams, until you replace the CIS. But you can replace the CIS without doing the internals first. Another inexpensive bolt on is to get an MSD 6AL and a matching coil. You'll not only get two sparks (up to 3000 rpm, idling and cruising), but you can also set a bigger gap/spark on your plugs. Your butt dyno won't notice it, but your ears will tell you it's running a little smoother.

Do you really need bigger brakes or would slotted rotors and more aggressive pads be enough of a boost? It's a noticeable improvement, but maybe you want more cooling capability for on the track?

Wheels and tires? Everything, literally everything, your car does passes through the wheels and tires. However, I'll mention that bigger tires up front will reduce the nimbleness of the steering. Also, when I changed from 16" wheels to 17", the ride got harsher. Of course I got tires with stiffer sidewalls at the same time. I'm back on my 16" Fuchs for now, but I'll keep two sets going forward.

Stiffer torsion bars and sway bars are tightly associated with your goal, so I can't speak to that. But it's most likely that all the rubber bushings are tired. Upgrade to the turbo tie-rods. If you plan on lowering the front end, get a bump steer kit?

Surprisingly, you didn't complain about the shifting? There's a two piece kit for the bushings on the bottom of the shift lever. There is also a shift coupler under the plate behind the front seats. I found the rubber in mine was crumbling. You can just replace the rubber or upgrade to a more positive after-market coupler. I found the after-market couplers transmit more engine and transmission noise into the cab. There are after-market shifters. Shifting is a big part of the driving experience, so I'd recommend taking a hard look at them. But stay away from the low-end short shift kits. They just make the problem worse. (The exception is Porsche's own short shift.)

Install the pop-off on the air-box now, even though you plan to remove it eventually. It has a lot of resale value. Trust me I know.

Lots of incremental stuff to think about before tearing into what appears to be a sound engine.

Michael S. Jackson
'78 SC w/Bitz EFI