Bosting Power in a 911 2.7

Logan175 · 12:55 PM

Hey there, what can be done to boost the power output of a 911 with the smaller 2.7L engine? Are there any F/I kits or am I gonna be on my own for fabrication?

Are there any simple bolt ons available? if so where?

And what is the possibility of retro fitting a 3.2 in a 77 911?

thanks a lot for your imput, I just wanna get some info before I spend the cash and go the lengths needed to bring a car from the US into Canada.

So please share your Ideas and all of you suggestions will be noted.

Thanks a lot
Logan

petrolblue83911 · 12-10-2006, 01:08 PM

First,

-assess,

1. what is the shape of your current engine? if it is going to need work soon, save your $ on upgrades until you tear into your motor

2. Are you going to keep this car for a while? if now do you want to put cash into it?

-The most popular perf. upgrades for the post 73 cars is the "ssi-heat backdate work. This means a set of SSI stainless heat exchangers which are designed to mimick the pre 74 heat/exhaust system which was much more efficient. Combine this with a 2 in and 1 or 2 out exhaust and your up 10-18hp depending on who you talk to.

Cost wise, -I did this to my SC last year and it ran about 1200.00 for parts which is a decent price for real SSI's, a dansk 2in 1 out exhaust and the heat backdate hoses/pipes

Logan175 · 12-10-2006, 01:12 PM

The motor in the car we want to get seems ok, the first owner had work done on it before he sold it to the gentalman I may buy it from. It only has 55k miles on it.

2.yes I certainly plan on it, yes we want to put cash into it, its the whole idea a project for my dad and I.

what about F/I or engine swap?

al lkosmal · 12-10-2006, 01:20 PM

I second the SSI upgrade and recommend the Dansk 2 in-1 out. If you are interested in upgrading from the CIS injection system to EFI, I'd recommend the tbitz system, sold by Tony Bitz. His website id www.tonybitzracing.com, I believe. These both can be considered do it yourself, bolt-on upgrades. For more power than that (and increased complexity) you will need to dig in and upgrade to higher compression pistons, hotter cams, etc. First thing I'd do is buy Wayne Dempsey's book "How to rebuild & Modify Porsche 911 Engines" Several engine upgrade combinations listed in that book. As far as upgrading to a bigger engine. Just search this BBS and you'll find a bunch of info by many that have done it.

petrolblue83911 · 12-10-2006, 01:23 PM

You can do either FI, -various options out there,

-if you want to go that way, post a new message asking folks about their FI swaps etc... as you'll get more action on that.

-swap to a 3.2 sure that would be sweet, the trick is to find a good motor to swap to..be cautious about buying unknowned used motors. I think a few guys will chime in here, but if as you say you have a solid 2.7 (I'm guessing it's been gone through and updated to resolve the mag case issues) you can do some fun things to that motor to make a fast car! so you have a few ways to go.

T77911S · 12-11-2006, 03:18 AM

whats the cost on the EFI?

Logan175 · 12-11-2006, 02:33 PM

the EFI kit he has the full one is 1.7k, maybe extra is you wanna go with a short air intake which elimates the air box completely. But 1.7k if you use the stock air box.

Logan

T77911S · 12-11-2006, 03:09 PM

not bad, cheaper than PMO's

dd74 · 12-11-2006, 09:09 PM

The suggestion for the SSIs or '74 and earlier heat exchangers is a good one - along with a two in, single out exhaust. It will give your engine some longevity because the '77 2.7s was riddled with smog equipment which heated them literally to death.

The 3.2 is a good option - if you need it. I'd first work a bit with the 2.7, and not necessarily with the engine, but the transmission and the general weight of the car.

The easiest to tackle is the weight. Within two hours, you could strip out upwards of 200 lbs out of the car, and have a faster car, better handling and braking car. What will go is the spare tire/wheel, the rear seats, sound deadening, even the radio and speakers.

More complicated is addressing the transmissions ring and pinion. If you can find a 7.31 r/p from a '74 915 transmission, and plop it into yours, it will render almost moot any of the small hp. changes you can make without tearing down the engine.

Will your car be fast after that? 1974 2.7s with 7.31 r/p and just 150 hp, went 0-60 in 6 seconds. And it had a stock weight of 2500 +/- pounds.

afterburn 549 · 12-11-2006, 10:05 PM

I am a thinking your 2.7 will be plenty exiting if like said, do a few delets to get it near the 2300 lb mark ( not hard ).
You dont need no stinking spare, crash bumpers , rear fan, 40 batt, rear glass window,.. heck the rockers and rear seats with belts will get rid of 20 lbs. MO

dd74 · 12-11-2006, 10:20 PM

Quote:

Originally posted by afterburn 549
I am a thinking your 2.7 will be plenty exiting if like said, do a few delets to get it near the 2300 lb mark ( not hard ).
You dont need no stinking spare, crash bumpers , rear fan, 40 batt, rear glass window,.. heck the rockers and rear seats with belts will get rid of 20 lbs. MO

Hell, I got my '74 2.7 down to 2200 with all the stock body parts still in place - well, except for the ducktail.

afterburn 549 · 12-12-2006, 07:00 AM

I will call that amazing ! How?

gatotom · 12-12-2006, 09:31 AM

Logan175....all I can say about a 2.7 is what i know about my car.

At 139k my california car got a new lease on life, a complete rebuild with all the latest and greatest at the time(1993), nikisil, ssi, tensioners, balanced and a transmission rebuild. Since then everything else on the car has been replaced or rebuilt, it is a coupe without sunroof, no ac, Yes, FI was rebuilt with engine, works great. Spent 13k at the time which re-enforces my belief that if you want a solid P car 20K is a minimum investment.

Now, it has 215k on the clock, I take it to the guy that rebuilt it every 15k for its tuneup and whatever it needs and it serves me very well.

Will I ever replace this car, probably not, don't drive it enough and I would rather spend my money on my sailboat. Is it the latest and greatest, nope.....but its all paid for

I have always been a believer in the fact that the porsche engineers know more about this car than myself and if the engine came with cis well, that is the best for it. That is why new cars come out, new this and that but still a porsche.

Everyone says the mids 74-77 are the garbage porsches cuz of the motor and thermos, yes, it was a crap design but they were still the last of the lightweights. With alittle bit of love and updates the mids can become your rocket sled, it is still about weight/horsepower ratio.

bigchillcar · bigchillcar's Garage

david (dd74) gives good advice. if it's power/acceleration you're after, the best options are what he suggests - the 7:31 rearend gearset (no you can't have mine

) or a bolt on turbo like the bae. there are several guys on the board with this turbo. it works well on the 2.7 due to thelow engine compression, but expect a shorter life from the engine.
ryan

dd74 · 12-12-2006, 10:30 AM

Quote:

Originally posted by gatotom

Everyone says the mids 74-77 are the garbage porsches cuz of the motor and thermos, yes, it was a crap design but they were still the last of the lightweights. With alittle bit of love and updates the mids can become your rocket sled, it is still about weight/horsepower ratio.

The funny thing is, the '74s had no thermal reactors, and were the last year with equal length heat exchangers, and the 7.31 r/p. '75-'77 are the models that got the short stick.

Apart from the Carrera and RSR Carrera, I think the 911 up to '73 is not as visually appealing as the '74-'89. It might also seem the middle years - '74-'77 - have the smallest footprint as far as aerodynamics go.

Here's one interesting tidbit - it was suggested to me that if all middle year cars had 7.31 r/p and are capable of reving to 7,000 RPM with power, they could achieve 160 mph.

I'd have to look at my gearcharts, but if true...wow!

gatotom · 12-12-2006, 10:48 AM

dd74....thanks for the correction, 75 is when the thermos started.

I have had my bunny up to 145, no more than that...way to scary....front end got real light.....need to work on the aerodynamics.........O'ya, that will happen in my next lifetime.

safe · safe's Garage

Quote:

Originally posted by dd74
Hell, I got my '74 2.7 down to 2200 with all the stock body parts still in place - well, except for the ducktail.

HOW??

T77911S · 12-12-2006, 12:39 PM

does the 7.3 r/p reduce top end?
i was told the late 77's had the light weight bodies but were the first to be galvenized? also porsche put in the dilivar studs in these 2.7s. anyone know the scoop on this?

bigchillcar · bigchillcar's Garage

yes, the 8:31 replaced the 7:31 and allows 5-10 mph more top end, if i'm not mistaken, at the expense of acceleration.

gatotom · 12-12-2006, 12:47 PM

T77911S... I believe the late 74 early 75 were the first to get totally galvanized taking the car out of the rust ages, yes, that added some weight but it sure beat being rusted out.

The divilar studs and timeserts kept the heads from coming apart. The mag motor was famous for that due to the fact that it was bored out to its max which was alittle too much hense divilar studs and timeserts.