Building out a happy 3.2L or 3.4L

[jager911]

I have a healthy 3.2L which doesn't smoke and seems to make decent power but I want more power rather then selling the car.
Only mods are K&N air filter, SW chip, European headers and M&K mufflers or megaphones.

I'd like to try to get 250-260hp by using new 10.3:1 Mahle Ps&Cs, 964 or 993 cams, headwork, larger valves and custom tune.

Is this feasible? What are the options to go to 3.4L? Do I need a different crank to get more displacement? I want to stay with single plug, pump gas and Motronic to keep costs down and keep it simple and < $10k.

Looking for feedback esp. from anyone who's been down this road and ran the engine on a dyno.
Alternatively, I could sell the 3.2L and buy a 3.6L but that opens up another list of issues for modifications needed.

[IROC]

I'm no expert (how's that to start out ), but I think 250-260 hp is very achievable. My 3.2 has 10.3:1 Mahle P&Cs, SSIs, SteveW chip and is otherwise stock and mine dyno'd at 235 hp with a bad full throttle switch that caused it to run very rich (I ran the M&K track mufflers during the dyno runs). According to SteveW, fixing the switch should have netted me ~10 hp, so I should be right at 245 hp or so.

And this is on 93 octane - single plug. I use race fuel at the track. Add cams to the mix with your better exhaust and I don't see how 250 shouldn't be easily achievable.

[jager911]

Originally Posted by IROC

I'm no expert (how's that to start out ), but I think 250-260 hp is very achievable. My 3.2 has 10.3:1 Mahle P&Cs, SSIs, SteveW chip and is otherwise stock and mine dyno'd at 235 hp with a bad full throttle switch that caused it to run very rich (I ran the M&K track mufflers during the dyno runs). According to SteveW, fixing the switch should have netted me ~10 hp, so I should be right at 245 hp or so.

And this is on 93 octane - single plug. I use race fuel at the track. Add cams to the mix with your better exhaust and I don't see how 250 shouldn't be easily achievable.

Mike,

That's good to hear so 260 should be doable I guess with cams, headwork and bigger valves.

[88-diamondblue]

I did the 3.4L route and dyno'd at 261HP. Cams and the usual upgrades while doing the rebuild. If I had to do it over I would go to the 3.5L P&C's. The 3.4 are not a full 3.4 displacement and the 3.5's are slightly above 3.5l. A cam from John @ DR Camshafts. Power really comes on at about 3700-3800rpm and rev limiter set at 7000RPM.(aftermarket rod bolts and able to hold the gear instead of shifting just before a corner) Single spark plug with 91 octane tuning. Steve W did the custom chip tuning. The car is a lot of fun. you can probably do it for $10k if you do almost everything yourself. Mine came in at about $7500, 6 years ago. It was a great experience rebuilding the engine. Wayne's rebuild book is priceless

[Rodsrsr]

The problem with the 3.2 is that the cost to go bigger PCs is not worth the extra HP. For the amount of money you will spend, you could probably just put in a 3.6 and have close to 300 hp.

[jager911]

I considered 3.6L as an option but buying a used 3.6L is an unknown and total cost is ~$15k, not counting that I have a mag case 915 and 6 bolt axles, all of which I'd probably need to upgrade.
If I could build a 3.4 or 3.5 for ~$10k, I'd have a reliable known motor to last 10+ years.

[Rodsrsr]

Originally Posted by jager911

I considered 3.6L as an option but buying a used 3.6L is an unknown and total cost is ~$15k, not counting that I have a mag case 915 and 6 bolt axles, all of which I'd probably need to upgrade.
If I could build a 3.4 or 3.5 for ~$10k, I'd have a reliable known motor to last 10+ years.

Cant argue with that either. I tossed this around for over a year and finally decided to turbo my 3.2 which just had a fresh top end rebuild. Forced air isnt for everyone, but one drive on boost with an open wastegate and holy **** your hooked! It simply yields the most hp per dollar by far, plus its fun to waste all the new high performance cars in a 30 year old P-car.

[JV911SYDNEY]

Not trying to burst your bubble but $10k is a little optimistic for a 3.4 when you consider pistons and cylinders alone are >$5k and cams >$1k. Plus headwork, MAF, remap, bigger valves, valve seats, valve guides, valve springs and retainers. If the cylinders are "machine fit" like the 3.8 ones then you'll need to machine the block too.

Plus anything that needs replacing (worn/pitted rockers maybe) and all the parts required for a rebuild (bearings, gaskets etc etc) and all the other random "while you're in there" things and general maintenance.

Then you'll probably want a lightened flywheel and clutch ($2k) to let your fresh motor spin more freely and new headers if your current ones aren't up to the task.

It all adds up!

[JeremyD]

Originally Posted by JV911SYDNEY

Not trying to burst your bubble but $10k is a little optimistic for a 3.4 when you consider pistons and cylinders alone are >$5k and cams >$1k. Plus headwork, MAF, remap, bigger valves, valve seats, valve guides, valve springs and retainers. If the cylinders are "machine fit" like the 3.8 ones then you'll need to machine the block too.

Plus anything that needs replacing (worn/pitted rockers maybe) and all the parts required for a rebuild (bearings, gaskets etc etc) and all the other random "while you're in there" things and general maintenance.

Then you'll probably want a lightened flywheel and clutch ($2k) to let your fresh motor spin more freely and new headers if your current ones aren't up to the task.

It all adds up!

I built a 3.4 that sang like a scalded cat

Oh Dyno we will go...

single plug - 993ss cams - SW chip

[jager911]

Originally Posted by JeremyD

I built a 3.4 that sang like a scalded cat

Oh Dyno we will go...

single plug - 993ss cams - SW chip

Jeremy,

That's awesome. I will look more closely at 3.4L. It fits my requirements.
I made the mistake of driving my buddy's '86 911/3.6L with 305hp at the Glen this w/e and the stock 3.2L won't cut it any more as I can't catch him.

So I gathered, this is your build when it dyno'd at 244rwhp or 290 fwhp:
3.4 mahle 9.8 to one jugs (are 10.3:1 not available?)
extrude hone
993ss cams
arp rod bolts
enlarged throttle body
competition springs and retainers
964 B & B headers
Magna flow muffler

After building this motor, why did you switch to a 3.6L? Was it reliable? I notice you did not go with larger valves.
I need to put a price tag on all this and start buying parts for a winter project. I will compare to dropping in a 3.6L and sell off my 3.2L.

[JeremyD]

I didn't twin plug - so stayed at 9.8 to 1. We also get good gas in Florida - I can tell you that even in a heavier cabriolet - I could chase down 964's and 993's at Sebring on a regular basis.

with this car (the 1974) I thought it would be cheaper to go the 3.6 route - but after rebuilding the 3.6 after buying it - not sure I can stick to that idea

[jager911]

I thought 10.3:1 can tolerate 93 octane without twin plugs. I had a '74 targa with a built-up 3L that combo and it worked fine. It also had a cross-drilled crank which made it a nice rev-happy motor.
Is cross-drilling the crank recommended and anyone know the cost? Trying to come up with a menu and the cost/benefit so I can choose what to spend on, or raise the budget if it makes sense "while I'm in there".

[88-diamondblue]

Here is a great thread to look at 3.2 to 3.5L - It's finally started!!! . As well as JeremyD rebuild thread too. Lots to look at

[quattrorunner]

Originally Posted by Rodsrsr

Cant argue with that either. I tossed this around for over a year and finally decided to turbo my 3.2 which just had a fresh top end rebuild. Forced air isnt for everyone, but one drive on boost with an open wastegate and holy **** your hooked! It simply yields the most hp per dollar by far, plus its fun to waste all the new high performance cars in a 30 year old P-car.

+1
Cost to hp is much better with turbo. Course that's just the start. Once you've been bitten by boost then is when you're screwed financially. But there is nothing like it. You simply can't touch a turbo 6 for the money without using an LS engine or newer Porsche 996 engine power wise. And both those would cost more to do.
As a reference not that you're asking, it would cost somewhere around $6000 to turbo your car. And then it would seriously shock you.

[jager911]

Originally Posted by quattrorunner

+1
Cost to hp is much better with turbo. Course that's just the start. Once you've been bitten by boost then is when you're screwed financially. But there is nothing like it. You simply can't touch a turbo 6 for the money without using an LS engine or newer Porsche 996 engine power wise. And both those would cost more to do.
As a reference not that you're asking, it would cost somewhere around $6000 to turbo your car. And then it would seriously shock you.

Thanks for the input guys, I've had a Turbo, looking for normally aspirated for street/track use. Of course, you can make more hp per $ with a turbo or supercharger, just not what I'd like to do. The $6k is not enough, the engine would need a rebuild on top of that.

Picture of the patient.

[thethrill]

BTDT with a 3.4 twin plug. I was disappointed. The motor had a custom chip and 20/21 cams and 1 5/8 headers. It was I a G50 car. It was ok. Nothing special. It was as fast as a 997 up to 100.


Do a 3.6 conversion. Lots more torque! Essentially you can trade your 3.2 for a 3.6. Do a mild build on the 3.6 (this will cost less than a 3.4 build) run the 993 ss cams, arp rod bolts ti retainers a custom chip and some headers or 993 heat exchangers and your good to go...

Less $$$$ and more performance. Remember the 3.6 is already twin plugged and is 200 cvs larger than the 3.4...l

[KNIGHTRACE]

The 3.4 kits do not work well with the DME however I can design a DME 3.2 that will make 240hp at the rear wheels with my heads cams and timing and euro 930/20 piston and cyl kit. However the 964 motors I do with stock injection and tricks make 290hp at the rear wheels. If you step away from DME I have 6 butterfly kit 3.4 motors that make 290hp at wheels. I also have a kit to put a water cooled GT3 motor in early car and even have early car with water cooled Gt3 motor for sale Call William Knight 615.969.4917
Also if you want the best I can build air cooled check out my 6 butterfly twin turbo kit. 580Hp at wheels no lag..... William Knight

[jager911]

Originally Posted by thethrill

BTDT with a 3.4 twin plug. I was disappointed. The motor had a custom chip and 20/21 cams and 1 5/8 headers. It was I a G50 car. It was ok. Nothing special. It was as fast as a 997 up to 100.


Do a 3.6 conversion. Lots more torque! Essentially you can trade your 3.2 for a 3.6. Do a mild build on the 3.6 (this will cost less than a 3.4 build) run the 993 ss cams, arp rod bolts ti retainers a custom chip and some headers or 993 heat exchangers and your good to go...

Less $$$$ and more performance. Remember the 3.6 is already twin plugged and is 200 cvs larger than the 3.4...l

The 3.6L makes sense for bang for the buck, I'm concerned with a mag case 915, it won't hold up, I will need to upgrade the tranny to newer 8/31 915, good idea to install tranny oil cooler, then the 3.6L would benefit from dual oil coolers as there is no engine oil cooler, it goes on and on. Was trying to keep it simple and still being optimistic at $10k.

[michael lang]

jager911, I was in an 87 Targe at SPR one weekend with an instructor that had been redone to 3.4l. My expectation was a big jump in power and I was expecting the car to pull like a freight train especially out of T9 climbing the hill and I was anticipating being able to really gap guys from T5-T8 and all weekend long I kept expecting the car to go faster eventhough the instructor I was with appeared to be driving as hard as he could. He was on Hoosiers with full cage and over the course of the weekend he was clicking off 1:28s and a couple of 1:27s if he was good coming out of T10. In my relatively stock '89 w/3.2l I'm consistently in the 1:29s and I'm sure if I really stretched my comfort zone there is a coupe of seconds to be shaved. Anyway my point is that you really should try get into a car that has had a particular mod done because I think you will find what you get may not meet your expectation. That's what I did and that's why I made some of the decisions I did in the modifications that I have over the years with my car.

[gumba]

I went with a mild 3.4 for our street legal race car (longevity). Mahle 9.5, stock heads, g80 cams, 50pmo, twin plug, 1 5/8 headers, custom exhaust, 325 chp on the Jerry Woods dyno. 100 octane for the track, and 93 (California) on the street.
Previously we ran a 3.2 with sw chip, SSI's and sport muffler. With that set up the best bang for the buck was swapping out the 8:31 for a 7:31 in the '84 trans. If felt like we picked up 20 h.p. at the bottom end.