LP944

Primarily for 83-85 944 NAs
I was thinking about possible ways on how to get a little more power out of an NA, yes they are expensive but just a thought if they were a lot less costly. CUSTOM JOBS! REMEMBER JUST IDEAS
1.) Lindsey racing or SFR Intake Manifold (Polish the internals of the manifold?)
2.) Custom throttle body spacer (no vortex just a spacer)
3.) bigger throttle body
4.) Lindsey racing style MAF system

I want to make some sort of open airbox type intake without it being open to the engine. I have a 944 carrera gt header panel I have yet to put on and had the idea of running some piping from one of the inlets to the airbox, and on top of that to put a brake duct right above where the stock cold air intake system is located. Might make a difference in power but definitely noise?

Oh well just some ideas. Tell me what you think and if they would even work! lol

Reimu

Cam
Supercharger
Exhaust/intake
Tune

JohnKoaWood

To milk more HP out of the N/A powerplant, you have to address the limiting factors from the factory.. while remembering the factory did a very good job of it back in the day...

Head.. this is the limiting factor, more so than the intake, throttle body, or where the air intake is...
MAF.. maybe, but again the head isn't outflowing the stock airflow meter..
Tune.. yes gains can be had here, but they are small, but require little in the way of cost or effort

exhaust... you will find that opening up the exhaust might just kill HP not free it.. again the factory did a pretty good job here..

opening the intake or exhaust without changing the VE of the motor will be like installing a huge back porch or huge entry way onto your 1br condo.. might look nice, and sound OK, but at the end of the day you will be trying to put out a fire by throwing money and gasoline on it...

the changes you list MIGHT get you 10-15 HP top end, while sacrificing low end torque at the same time.. the entire engine needs to be re-engineered to trully make any real gains...

Paulyy

Port polish?, if you have money to blow maybe bigger valves.
Or E85 and advanced timing, possibly slightly higher CR also?

JohnKoaWood

Higher than 10.2:1... maybe if it had some knock control installed, but that hasn't yet been brought up.. not to mention you will need not only new pistons but also a reworked head for this as the piston to head clearance is ... never mind... lots of work just to enable some gains... lots of work, and custom parts, and money.. lots and lots of money... custom worked head, custom pistons, new custom ground cam.. there are some who have done this type of work, and spent massive amounts of money..

and just remember, I am called crazy for pouring 2K into my N/A to bring it back to the street... the changes you speak of are easily another 2.5K.. on top of either sleeving or coating the block to accept the new pistons... it would be easy to spend over 10K just to have reliable usable power.. and still yield less than a modern cars engine output...

This is NOT a GM V8, nor is it a ford mustang.. intake, throttle body size and spacing, and the traditional bolt on changes for those types of powerplants dont have the same effect on these motors.. it just isn't gonna happen.. if you want to bolt on 50HP.. sell the Porsche and get a Honda, GM V8, mustang, or some other rattle trap.. it take much more work and money to get those kinds of gains on these motors...

Paulyy

I had forgotten these didn't come with knock contol units.

best NA mod is get an S2 engine and possibly an S2 trans (not sure how strong the n/a trans are) and mod that engine. you would get more gains with that engine.

dillon410021

just turbo it! lol

M758

There is maybe 10-15 hp out there if you work really hard. Beyond that you will need forced induction or major displacement increase or motor swap.

odurandina

a variocam engine with supercharger can be had for less than 8 grand.

(not saying that just because my 3.0 is for sale)... after that a blueprinted 2.5 or 3.0 turbo.

944V8inDFW

MODEST nitrous wet kit will yeild aroud 30-50 HP and be safe.

ritzblitz

A cam is a good place to start.

ZR8ED

What is the factory compression ratio? Shaving the head can yield a higher cr, and coupled with better airflow (ported head/intake and a hotter cam) is where most of the gains are likely found. IF you can't shave the head due to additional clearance issues, you could weld up the combustion chambers to increase the compression ratio. Couple that reduced combustion chamber size with improvements in getting the intake charge into the chamber efficiently and with a thoroughly mixed fuel and air mixture would be an effective alternative.

Any work that increases the VE of the engine is the place to start before getting into full rebuilds with overbores, increasing the stroke etc..

Some ideas for improving the VE (volumetric effiecency).
Port match and polish intake and exhaust. Match the intake manifold ports to the same shape and diameter as the cyl head ports. This theory is the same for all parts of the intake and exhaust. Its all about smoothing out the air flow, and reducing abrupt directional changes or obstacles like manufacturing casting burrs etc.
Reduced parisitic power loss. Remove power steering, air con etc
If you don't want to give those up, then installing lightweight and/or underdrive pullies.
Ensure any rotating parts are properly greased and spinning as freely as possible (more of a maintance item)
Lightweight clutch and flywheel.
Polishing and lightening parts is greatly expanded if you are pulling the engine apart.
Want to get more creative? port/mild polish waterpump, and any oil/water passages that you can reach.

I think that 30-40hp is totally achievable using some of the techniques that I have mentioned. I've never seen one of these engines apart, but I'd love to help someone work on one to see how much hp we could get.
This is by far not a complete list, so feel free to add more ideas. I love these kinds of topics!

elzergone

How come I never see anyone picking up some Euro NA pistons? Aren't they supposed to be higher compression?

What am I missing here.

odurandina

100 octane gas and a fat budget.

Erzengal

Cam's are mentioned a lot, but I can't tell what you actually get number wise. For $600 - $700, I want to know what you get. I thought about it when I had my cam tower resealled. However the JM Cam and the Web cam websites are not very clear.

Anyone with these have any numbers?

Supercharger would be fun if it was in the $2k - $4k Range, and kept A/C. The Stage1 Kit from SFR would be tempting, if it didn't require loss of A/C.