Need your opinion on these engine performance upgrades

[Trakrat]

All,
I'm trying to decide on what upgrades I should get for my 3.2.

Here's what I'm thinking...
- 3.4 Mahle piston & cylinder set 9:8:1 compression
- 964 style camshafts
- 360lb valve springs w/ titanium retainers
- Pauter connecting rods (545 Grams)
- 8.00lb flywheel
- upgraded clutch set


Any opinion on this setup?

[Tippy]

How about 993SS cams?

[chrismorse]

For track or "spirited" driving, I would go for lighter flywheel and pressure plate.

Chris

[75 911s]

Your cam choice will depend on intake in my mind. what intake and exhaust are you thinking Track?

I'm in the same boat. I'm looking at different builds based on the 3.2 that I have.

Turbo is really exciting, but an entirely different animal and will require quite a bit of cash monies to get done.

Right now I'm looking at an extreme budget build just to shorten the project timeline. I think I can get my 3.2 project in the car for 10k out the door with ITBs diy EFI and reusing my SSI exhaust that I already have. I would re-use the P/C's but put new cams in to go with the ITBs.

The upgrades you listed above for a 3.4 was the first option I looked at. What made you decide on the mahle p/c? Wont that run you 4 times more than say boring your mahle cylinders and running JE or CPs?

Are you thinking dual spark for that?

[reefdiver]

Doing research for the same type of build on my 87. Wish someone who went through it would tell use the good and bad of this build. Also what does the machine shop need to do, and what will help longevity and performance.

[Catorce]

Really tough to comment on this without knowing your intended use and performance goals. I know your username is Trakrat, but is this a street or track car?

[Trackrash]

Trackrat,

This has been answered many times, you should know the options.

What are your goals? Street, track, something in-between?

Will you need to meet smog testing requirements?

What is your budget?

A simple rebuild will cost you around $20k. A Singer 4,0 will cost $100k.

It's all been done before, you just need to decide your options.

BTW, those valve springs and rods aren't needed if you intend to use the stock Carrera intake and the 964 cams.

[mo-mon]

Someone wrote this in regard to improving the 3.2 performance & I saved it.

Change to ARP or Raceware rod bolts, shot peen the rods, higher pressure valve
springs, 964 oil pump, 964 cams, a matching chip, and restrict the upper end oiling with the 91 turbo cam oil rest
rictors and it should spin to 8 grand. Apply some restraint and limit the revs to 7,200 and you have a reasonable
reliable upgrade to the motor. (add the Mahle 3.4 or 3.5 P/Cs and see a real improvement!

[GaryR]

How do you plan on supplying fuel to this?

[Trakrat]

Originally Posted by Tippy

How about 993SS cams?

a couple of shops that I called did not mention or recommend 993SS

[Trakrat]

Originally Posted by Catorce

Really tough to comment on this without knowing your intended use and performance goals. I know your username is Trakrat, but is this a street or track car?

Considering that my driving on the street and driving on the track are very similar (go fast and try to pass the slower cars).... I'd say it doesn't really matter.

I'm not trying to build the engine for a specific application. I'm just trying to make the engine run better than it does.

[Trakrat]

Originally Posted by chrismorse

For track or "spirited" driving, I would go for lighter flywheel and pressure plate.

Chris

Any suggestions on manufacturers or personal opinions on any specific brands?

I know the stock pressure plate is a monster... but I'm concerned about clutch feel too.

[Trakrat]

Originally Posted by 75 911s

Your cam choice will depend on intake in my mind. what intake and exhaust are you thinking Track?

I'm in the same boat. I'm looking at different builds based on the 3.2 that I have.

Turbo is really exciting, but an entirely different animal and will require quite a bit of cash monies to get done.

Right now I'm looking at an extreme budget build just to shorten the project timeline. I think I can get my 3.2 project in the car for 10k out the door with ITBs diy EFI and reusing my SSI exhaust that I already have. I would re-use the P/C's but put new cams in to go with the ITBs.

The upgrades you listed above for a 3.4 was the first option I looked at. What made you decide on the mahle p/c? Wont that run you 4 times more than say boring your mahle cylinders and running JE or CPs?

Are you thinking dual spark for that?

I'm going to have my stock intakes polished... and will be keeping fuel and air stock (except for a chip to change timing).

The exhaust I've had is a fabspeed straight pipes that has been ceramic coated. Thought I don't like it and will probably switch to a Rarlyl8 M&K exhaust and GT3 muffler.

As for the piston & cylinders... I'm looking for something that I can just swap in and out. As I understand... I can just drop in the piston & cylinders without making any permanent changes.

I need to keep compression below 10 because I don't want to go dual spark... again, because I don't want to make permanent changes to the engine.

[Trakrat]

Originally Posted by GaryR

How do you plan on supplying fuel to this?

Well... that's a good question. I'm planning on keep everything stock and then see how things perform on the dyno. I will be sending my injectors our later this spring to have them cleaned and tested.

Given that I'm not changing how much air I'm adding, I can't see why I would need to change how much fuel I'm adding.

[Bill Verburg]

JMO, but unless you are emulating a known system you are better off having a pro that has been there done that to spec and build the motor w/i the framework of your intended use

[lvporschepilot]

Good stuff there. I just want to add you do not need valve springs that stiff with a 964 cam. You will be robbing power parasitically wth them. My company actually just ran the data with means valvetrain component weights and several cam lobe ramp acceleration rates to deduce what is actually required to control things at up to 8000rpm including 10-15% buffer. I’ll spare the technical stuff. Anyway, Dougherty camshafts or Craig Garrett both have a good option for about half of what Aasco want.

[Trakrat]

Originally Posted by Trackrash

Trackrat,

This has been answered many times, you should know the options.

What are your goals? Street, track, something in-between?

Will you need to meet smog testing requirements?

What is your budget?

A simple rebuild will cost you around $20k. A Singer 4,0 will cost $100k.

It's all been done before, you just need to decide your options.

BTW, those valve springs and rods aren't needed if you intend to use the stock Carrera intake and the 964 cams.

My goals are to build a strong, reliable engine... that can be as much fun on the track as it can on the street.
However... building the car for the track is more about suspension than engine, as I do more auto-x than road course. I'll work on upgrading the suspension next year.

No smog here (been running open exhaust before engine rebuild).
$20k is what I've been hearing from others on a rebuild as well... but I'll be doing the actual labor myself on the rebuild. so the money I'm saving is going towards parts. So far, I'm estimating $10k - $20k to get where I want to be, which includes all machine work (porting and polishing EVERYTHING) and performance parts.

Why do you say that about the springs and rods? My reasoning for those is that I want lighter rods to lighten the mass of the engine... thus faster revs... and the stronger springs should help the valves keep from floating for those high rev moments.

[Trakrat]

Originally Posted by lvporschepilot

Good stuff there. I just want to add you do not need valve springs that stiff with a 964 cam. You will be robbing power parasitically wth them. My company actually just ran the data with means valvetrain component weights and several cam lobe ramp acceleration rates to deduce what is actually required to control things at up to 8000rpm including 10-15% buffer. I’ll spare the technical stuff. Anyway, Dougherty camshafts or Craig Garrett both have a good option for about half of what Aasco want.

Then the question is... does someone make lighter springs that are less stiff?
what strength springs do you recommend?

Also... I had planned on having my rockers machined to match the cams for better surface contact.

[Trakrat]

Originally Posted by mo-mon

Someone wrote this in regard to improving the 3.2 performance & I saved it.

Change to ARP or Raceware rod bolts, shot peen the rods, higher pressure valve
springs, 964 oil pump, 964 cams, a matching chip, and restrict the upper end oiling with the 91 turbo cam oil rest
rictors and it should spin to 8 grand. Apply some restraint and limit the revs to 7,200 and you have a reasonable
reliable upgrade to the motor. (add the Mahle 3.4 or 3.5 P/Cs and see a real improvement!

seems others are saying NOT to go with higher pressure valve springs... as for the 964 oil pump... I think I am going to send my oil pump out to have it polished and improve its pressure.

Tell me more about the 91 turbo cam oil restrictor... I'd like to look more into this.

[lvporschepilot]

Originally Posted by Trakrat

Then the question is... does someone make lighter springs that are less stiff?
what strength springs do you recommend?

Also... I had planned on having my rockers machined to match the cams for better surface contact.

Yeah slightly lighter springs are available with Dougherty cams or Craig Garrett (cgarr on pelican). They are more stable than stock with high lift capabilities but not as much pressure as other aftermarket but a bit higher than stock. Craig can also work your rockers/heads and turn them around super quick, he’s always been fantastic and super reasonable. Always run fresh rockers on a new cam.