performance upgrades for a 911sc 3.0
 

Hi guys,

I am trying to milk to most power possible from my little 3.0 SC

I know of the following upgrades:

heat exchangers -or-
cat by-pass
air filter (minimal)

what else are my options regarding power?

ThaNKS,

ROB

Weight reduction. Spare tire, jack, non working AC.

besides headers (SSI) and a sport muffler there isnt a whole lot to do that isnt going to cost $$$. you could get a new cam and a set of reconditioned weber carbs. thats about it without pulling the engine apart

+1 on the wieght reduction...rear seat, a/c, smog pump

With the tough smog laws in California, I have gone with the weight reduction/better handling/improved braking route.
I also have a 3.0 litre and less weight has really improved the overall performance.
I swap a cat by pass every 2 years for a cat and smog test, and the by pass seems to let it breath better. Everything else is either totally illegal or very expensive.

sell your motor for $4500, buy a 3.2 for $5500.

3.2 jug upgrade?

And for a little more, throw in a 3.2 crank and rods and go 3.4.
And a little more, and a little more, and a little more .................................................. ................$

Replacing your existing exhaust with an older style will gain you 17-22 hp. Going to Webers 40 ida 3c will get you 20-30 hp and better throttle response.
If you want to do internal engine mods you could install 3.2 p/c with ge 40
cams and weber carbs, older exhaust for a total of 250-260 hp. But if you
really want some hp for about $800.00 install a turbo and see 300 hp
and ~325 tq. You can buy a turbo(new) off ebay for $250.00. A tial valve for
$50.00. misc parts and plumbing and a 914 cold start valve with pressure
valve.

I, too, have been thinking about this same problem with my SC. What is the longevity issue with going turbo? has anyone done this to their 3.0?

As long as you don't get crazy on the boost. Keep the boost no more than
.6 bar and you'll be fine. Remember, the sc is a 930 box.

Many here have done it, just do a search

This motor was 3.0 sc some time ago...J&E pistons,964 cup cams,40 webers,backdated exhaust with dual in dual out M&K mufflerhttp://forums.pelicanparts.com/uploa...1204169451.jpg
http://forums.pelicanparts.com/uploa...1204169474.jpg

guys,

I like this turbo idea...anyone give me a shopping list of what I need? Expected costs to get a "pro" to install? In short, is it cheaper than buying a turbo engine?

Does this mean SSIs and e.g. an M&K or Monty exhaust will give an SC 17-22 hp more?

Nice looking engine! What pistons(cr, and any valve pockets) also, what venturis and jets on the webers.
Been dynoed?

Yes and no. The biggest gain is in the midrange, where you can expect to see this difference. The area between 3,000 and 3,500 revs will show the biggest gain. There will be gains above this area and below it, but that should be where you see the biggest difference. At the power peak, the difference will be less than 10, maybe closer to 5.

JR

CR is 9.5:1,yes they have machinned valve pockets,as webers set up for now I have 36mm venturis,180 main jets,65 idle jets,can not drive it too much beacouse of this year chicagolands tough winterhttp://forums.pelicanparts.com/uploa...1204204990.jpg

Depends on how many miles your engine has but I would start with a valve job.

While you are there change yours camshafts regrind to 964 profile: $250.

Maybe 9:5 or even 9:8 pistons: $1000 new.

SSI + sport muffler.

Vincent

are these "must do" items or upgrades as we go along...

I rebuilt mine 3 years ago. had 170,000 when I did it now has close to 190,000. 9.5:1 J&Es, 964 cams, SSIs with a Monty dual out. All done because it happened not because of a grand plan. Bought the SSIs and Monty here, One piston skirt was broken so I replaced pistons, Cylinders were out of spec so I replaced those as well. Cams just seemed to make sense while I was in there.

Lack of track experience makes the car faster than I am. I am working on that again this weekend.

germaniac:
Forget the air filter as a HP-gain.
All these 3.0 liter upgrades have been discussed repeatedly here, do more search.
To gain ~40 HP, are you willing to spend $5000.-?
That's how much it is, parts and labour, to do the 964-cams, new P/C's, SSI's & muffler etc.
Once the engine is opened, all kinds of costs will appear like the heads need to be done and what about the head studs? It's silly to open the engine and not do the heads and studs.

If you budget only a couple thou, you'll get the SSI's & muffler plus the 964-cams and you'll need to do the work yourself.

So, how much do you want to spend?

Has anyone heard of the CIS trick to increase fuel mix at lower to mid rpms? I heard that Porsche held back on the fuel until wide open throttle?

JW,

Tell us to what you are referring.

I dont know, that is why I am asking! Its some wiring trick to the cis system that starts the power band increase alot sooner than normal. A local porsche shop owner told me that he could do it for an hours labor charge. It sounded like something that someone could do themselves. I may start another thread to see if anyone has heard of it...

I would pay the guy for an hour just to see what he did? Then share his secret to us!!!!!

I may just do that! :eek:

please post the findings either way on this thread as I am subscribed to this and I don't want to miss what you find if you go and post ~ start a new thread!
Thanks !!
Bob

[QUOTE=JR_NYC;3796838]Does this mean SSIs and e.g. an M&K or Monty exhaust will give an SC 17-22 hp more?[/QUOTE

I feel that 17 HP is definitely achievable going with SSI exchangers. I ran a few before and after tests using a G-tech Pro. See the link (it's been a few years) but the results are still valid.

Separately I had my SC dynoed after installing the SSI's. If your engine is in good shape, you will definitely feel the improvement. My car has 211k miles and has never run stronger. It really perked up with the SSI's. The SC benefits from the SSI's balanced headers. Very little else you can do without going into the engine itself.

http://forums.pelicanparts.com/porsche-911-technical-forum/7731-performance-test-done-ssi-vs-stock-sc.html?highlight=Performance+Test

what about msd?

header
 

what size header 1 5/8 ID=41mm engine 3.0 liter

If anyone is looking for any Performance related upgrades, please take a look at the link below. We're happy to answer any questions about the products.

Performance Brake Pads, Shocks and Springs, Air Filters and Exhausts - Pelican Parts


-Dmitry

I remember reading about this. I think some US and Cali cars had a brown wire at the DME you could disconnect - might have been the 3.2. Search brown wire dme

Edit found this:
Those brown wires are for California emissions purposes only; they would be connected, and the DME would use a different map. Unfortunately, that map also reduces power somewhat, so it's best to leave the wires tapes up and unused. If you check out Steve Wong's website (911chips.com) he has a nice explanation about all of this.

not exactly speaking of performanceupgrades from view of a race car but here's what I did to my 79 SC:

1. the obvious: weight reduction
- cleared the trunk (no carpet, no spare tire, no everything)
- switched to smaller/lighter battery
- deleted all of the AC stuff
- lightweight parcel shelf
- removed rear seat flaps (who needs theese anyway?)
- deleted radio & speakers (we are in the bluetooth / UE-boom age now, if needed)

2. injection:
- full tear down and refurbishment with lotsa cleaning and seals
- new injectors
- polished the inside of the 6 airpipes (smoother airflow)
- carrera fuel pump

3. ignition
- permatune 2.0 version
- rebuilt distributor
- new wires und plugs

4. exhaust
- SSI
- Dansk 952 sport muffler

at end I let the car be corner balanced (as bilstein Nürburgring went in there too) and I let the engine be regulated.

it revs like a champ, and running 220+ kmh is of no worry.

but @all: don't forget the brakes!! they should be better than good already before tuning.
at least attend them simultaneously.

Along with the upgrades previously mentioned, I will add a few more to consider.

You did not mention if your 3.0 is an early U.S. ('78/'79) or euro version. These 3.0's would be a better base engine due to the higher flow CIS & heads. Upgrading the heads and CIS is costly if it is a later U.S. spec 3.0.

I would also suggest (if your budget allows) Max Moritz Mahle P&C's for a slight displacement bump. They are hard to source used (and are costly new), but with the appreciation shown by the air cooled models, I feel they are a reasonable upgrade if a rebuild is due.

I am in the same boat with my '82 SC. My first mods were SSI's and and an M&K muffler, and they added a nice performance gain. I have been collecting parts for several years to offset the pain of my pending rebuild. My plan is to add early high flow CIS and heads, 964 cams, and Max Moritz P&C's (all sourced used) to add more power.

Also, consider removing weight (the Lotus mantra) to add a performance bump.

Trust me it's a lot cheaper to remove weight than add horsepower. I removed 150 lbs with a little fiberglass front and rear, lighter seats, lightened door panels, removed one of two batteries, M&K muffler (10 lbs vs 30 lbs) and more. All that compared to $12,000 when it came to the engine. All this on my 72T 3.0L.