944 HP Questions/Answers
 

12-11-2008: I will edit and add this post as I gather more information

I thought I would pin a sticky to the top of this forum because the #1 question asked by naturally aspirated 944 owners is "How can I get more power out of my 944." Hopefully this will help keep anyones feelings from getting hurt by responses that they do not want to hear (or that are not phrased the best, as typically it is a quick reply due to the question being asked so much). This is not a post meant to put anyones car down, it just illustrates what is possible with the car and what is not.

I have spent many hours dyno testing numerous 944 upgrades on a mustang 500SE dyno. My previous full time job was modifying Porsches for hp and performance (up to 1000hp in the 996TTs), as well as general maintenance on both Porsche street cars and race cars. Part time, I currently maintain and build 944 spec cars, and have my 951 dedicated track car, so I spend more time on the track, than off, so my experience with trying to get hp out of 944s is extensive. So, you can take my advise for what it is worth (free) and do as you choose, but I hope this guide helps to put things down on paper before you jump in and start throwing parts at the car.

The short of the question is this: You can not get hp out of a NA 944 without spending what I would consider serious money (in relation to the value of the car it is being spent on). Now I will break it down for you in the long version.

Cold Air Intakes:
Cost: $25-50 (ebay). Gains: Minimal, if not a slight loss.
Cold air intakes are all over ebay, get rid of that unsightly stock airbox with a cone filter! Unfortunately, what little gains that you will pick up from the cone filter, are immediately lost due to sucking in hot air from the placement in the engine bay. Remember, cold air makes hp, hot air decreases it. The stock airbox actually sucks in cold air from the fenderwell, and is not that bad of a system. Some will ask, what about the cone filters I see over behind the drivers side headlight. This is found on turbo cars, with an aftermarket mass air flow sensor setup. The filter is located over there, again to try and get away from the heat. A maf is a much better system than the stock AFM the 944 uses, and is much newer technology. In short, it creates enough hp, that a little heat soak still leaves you with positive gains (and yes, even over near the fender, us turbo guys still struggle with heat soak on a hot day). Can you add a MAF to the system? Read on.

Mass Air Flow Systems (MAF):
Cost: $1000-1200. Promax motorsports use to offer a kit, but I do not see it on their site anymore. IIRC it did get good reviews based on driveability. I can not remember the hp gains, maybe 10-15hp.
One of the biggest advantages of a MAF, is improvments in drivability. With a stock AFM, there are a lot of hesitation spots throughout the rpm range, specifically immediately when coming off idle. The MAF system will greatly improve the driveability of the car on the street.

Throttle Cam:
Cost: $30 Gains: None
Gains from a throttle cam (sits on top of the throttle body where the throttle cable wraps around): Increased throttle response is the purpose and result from the throttle cam. A nice little aid to daily driving.

Performance Chips:
Cost (Early): $200 est. FRWilk. Gains: 10hp
Cost (Late): $150-200 Promax Motorsports. Gains: Claimed 10hp (I have not tested a 8V chip, but have tested their S2 chip, which did not make the hp gains they claimed, in fact, there was extremely minimal difference, even when dynod on a few different occasions).
Cost (Late) $200 est. FRWilk. Gains: 10hp
DMEs differ from the early 944s (83-85.1) and the late 944s (85.5 on). The later DMEs have a removable chip which can be replaced. There are a few vendors out there that offer chip replacements for the late cars. Promax motorsports is one. FRWilk has been tuning 944 DMEs for quite some time, and really gets good reviews from his customers. Again, mostly the drive ability is improved, and power delivery. Overall gains are 10hp or less. His early chips also fix the "Shudder" issue found in the 83-85 cars.

Camshaft:
Cost: $650. Gains: 15-20bhp depending on other modifications
If I recall correctly, John Milledge use to make cams for the 944 NA cars. Last I had heard, he had moved to the west coast, and appears to still be in business. He was known for building some monster engines, both NA and turbo (also $$$$).

Exhaust Header:
Cost: $700-1000. Gains: 5hp. Racers Edge
Cost: $320. Gains: 5hp Bursch
Cost: $1200. Gains: Untested, but figure the same. Billy Boat Exhaust (B&B)
Cost: $300. Gains: Claimed minimum 14% gain. Untested: MSDS Exhausts

Exhaust Test Pipe:
Cost: $300. Gains: 5hp. Bursch
Removal of the catalytic converter (suggested for off road use only), will free up a little hp, but will also change the tone of the exhaust. Some will call it very raspy and unbearable, others have not minded it too much.

Exhaust Muffler:
Cost: $100-250. Gains: None
The stock muffler is a straight through design, and while switching it out to a different muffler will help to change the exhaust note, the hp gains will be nill if anything.

K&N Drop in Air Filter (Stock Airbox):
Cost: $50-100 IIRC
Gains: 2-3hp, a slight increase in fuel mileage
Drop in panel filters are available for the 944 lines. I have never seen a big increase in hp in either the NA cars or the turbo cars, but if the engine can breath better, it will produce more hp. With that being said though, K&N filters let a lot of microparticles through the filter and into the engine. If you smear a small dab of grease behind the filter in the intake track, and drive the car for a period of time and check it again, there will be significant dirt particles caught in the grease. Can the engine handle small particles, probably, but just for everyone's information. A stock Mahle air filter flows pretty well and does a great job of filtering.

RE: 944 HP Questions/Answers
 

Suspension Upgrades:
Cost: $1800 and upwards
This is an area that will really make the car faster on the track and in the corners on the street. With the 944s nearly 50/50 front to rear weight ratio, it will still hang with a lot of cars on the road today. With the right upgrades to the suspension, the car will outhandle most cars on the road. It is an area where you can spend a lot of money, or upgrade on more of a budget so to speak. Paragon-Products offers a spec racing kit which covers a good part of the suspension components. For about $1800, you can get new Koni shocks and struts with front coilover conversions and stiffer springs. It also includes weltmeister 28mm front and 22mm rear fully adjustable sway bars, and 30mm hollow torsion bars. This will definitely stiffen up the ride and corning ability of the car. Remember though, it is a tradeoff.....the stiffer you go for improved cornering, the rougher your daily ride will be on the street. Staying mild with a 250lb-300lb spring, and swapping in 968 M030 sway bars in place of the weltmeister bars would be a nice compromise for the daily driver. Or, maybe you just want to upgrade your worn out shocks. Do not bother putting in the stock boge/sachs replacements, upgrade to the konis, for a much better ride (and shock).
You can also spend a lot of money on the suspension if you are seriously tracking the car. Upgrading to a full coilover suspension kit can range anywhere from $2000 for a bilstein setup, to over $4000 for Motons, Penski, etc. The sky is the limit.

Forced Induction: Supercharger:
Cost: $4500-5500 Performance: 182rwhp (215 flywheel) - 222rwhp (260hp). Speedforce racing
Tim at Speedforceracing offers 2 stages of supercharger kits for the 944. The hp increases are really good, but I have not personally seen or tested his kit. He is well respected amongst the 944 community, and has a great product line, so the claims could be true. At 8psi boost on his stage II, and with the compression of an NA engine, I have to believe the motor is strung out pretty hard.

Forced Induction: Turbocharger:
Cost: Minimum $3k and upwards. I would figure a good safe number to be about $4500 plus install.
I do not know of anyone offering a bolt on turbo kit, so you have a couple of options:
#1: Buy all the components needed from a donor 944 turbo car, and install them on your motor. I figured the cost of buying used parts (I have parted many turbos, so I had an idea of what you would pay), and the parts totaled a little over $3k using all USED parts. There is a lot more needed than just the turbo. You will need all the cooling system, intercooler, headers, crossover pipe, full exhaust, coolant tank, auxillary coolant pump, DME, KLR, Manual boost controller, turbo motor mount, and the list goes on. If you do a search in this forum, you should find almost a 100% complete list I took the time to write out. Now, once the turbo is installed, you are going to only be able to run 8psi boost or so on the motor, or you will shell the internals. If you want to run the full stock boost, then you are going to have to do internal engine work to handle it (I.E. lower the compression of the engine to handle the boost).
#2: Buy a complete turbo motor and remaining accessories, and drop it in the car. This is probably the most cost effective way to do it. Buy a motor complete with the DME/KLR/Turbo, etc for $2500. Add the remaining hardware, and you are set to go (probably another $1000-1500 in parts). The other advantage of doing it this way, is that now you can modify that turbo motor with bigger turbos, chips, exhaust, etc, and REALLY bump the hp without fear of the engine shelling.

And of course.....
Lets not forget another obvious choice here: Sell the NA (or keep it), and buy a 944 Turbo. This is probably the most cost effective solution there is. Remember, that even with a higher hp engine in the NA, you still lack a lot of things the turbo cars come with standard: Bigger brakes (very important with more hp), newer style body, bigger and wider wheels, etc. A lot of people become very attached to their cars, and do not want to look down this road, and that is ok too, that is why there are at least a few options listed above that will help them out.

RE: 944 HP Questions/Answers
 

Thread is now unlocked for additional questions/comments. If you have some information that you think should be added to the guide, post it up, and I will get it in there. I still have information to add, but think there is a pretty good base going...

RE: 944 HP Questions/Answers
 

The clarity and brevity of this post is the most useful thing that I, a new 951 owner, have seen to date. How about the same post but for 951s?

RE: 944 HP Questions/Answers
 

Sure, I can put together something for the 951 as well. Just give me a few days.

RE: 944 HP Questions/Answers
 

I'm like a kid waiting for Santalooking forward to your post.

RE: 944 HP Questions/Answers
 

Hi
Thanks for all the usefull info, as it answered alot of the questions I had. Can you add anything on a K&N stock replacement (washable), and also for the suspension, polyeurethane bushings.
Thanks
Paul

RE: 944 HP Questions/Answers
 

I'll see what I can write up on the bushings. There is a lot of information on both poly and solid bushings so I had left it out, but I will try and summarize it. The short of it: Tighter suspension, a little more squeaking from the suspension.

RE: 944 HP Questions/Answers
 

I have to disagree about the design of the N/A muffler.The last time I cut one open I found it to have several tubes next to one another, not a straight through design like the 951 muffler. I was also suprised you did not mention the gains that can be achieved by shaving the cyl head and having a 4/5 angle valve job in conjuction with some of the other mods you mentioned. Many years ago I had an 86 that I built using an 83 short block, head shaved past the limit indicator, 4 angle valve job I/E, modified a idler roller to bring cam timing back around, MSDS header, fuel reg crushed to achieve 10psi over stock, custom Autothority chip, stock exhaust w/cat in place. As you may see, it was a budget build! It did make close to 190 though. You may not be able to get big numbers, but it can still be quite the performer.

RE: 944 HP Questions/Answers
 

The list is not complete yet, only a start. I haven't had much time to dedicate to it lately. I will add more stuff when I get time.

RE: 944 HP Questions/Answers
 

hey i am new to the forum and i think your post is excellent. i have a 87 porsche 944 8V. i got a good deal on it and bought it from the first owner. i was looking into your post and tried to find the supercharger kit but had no luck. can you please link as to where i can get one?

RE: 944 HP Questions/Answers
 

Sure, here you go :)

http://www.speedforceracing.com/prod...gers_944v8.php

RE: 944 HP Questions/Answers
 

Awesome details. Is there a swap guide of some sort that you (or someone else) knows of? Just something that says what can be used in place of what, between years and Turbo-N/A. Specifically, I'm hoping a 19686 turbo tranny can bolt up to my 1983 N/A for the LSD but I don't know where to begin looking.

RE: 944 HP Questions/Answers
 

I don't know of a parts interchangeability guide out there, but yes the transaxles do swap. You will find that most parts will swap between early and late cars, and between turbo and NA. Not all of course, but the vast majority.

You need to use the early transaxle mount, which will bolt right up to a late transaxle. The gearing may be a bit off though if you are using a turbo tranny in an NA. I have done the same with a turbo motor and driveline into our 84 widebody project.

RE: 944 HP Questions/Answers
 

Very helpful! Thank you!

RE: 944 HP Questions/Answers
 

Hi all

I found a bolt on supercharge that is Alternator driven that can hook up in place of a cone filter. It claims 1 PSI boost and only activates durring full throttle. The intake is a full 3 inches to compensate for a fan being in the airpath. Looks reqasonable especially if you can get the cone filter moved to the fender. Claims are 10-15HP which sound reasonable. Only costs 400.

Opinions?

RE: 944 HP Questions/Answers
 

Bogus.

RE: 944 HP Questions/Answers
 

Yep though it sounded fishy. One of those too good to be true things.

In any case I'm rather happy with my car at the moment, my only upgrade has been the Bursch pipe. I think it sounds great and seems to give it just a hair more pep wide open. Just my 2 cents...

This is a really informative right up. Thanks for taking the time to put it together.

I might have missed it but I would like to ad that these modification hp gains depend on the condition of your engine and how tightly everything seals up. You can get a feel for that by your compression test results and even better with a leak down test. Keep in mind that there may be a difference between the factories initial HP claims and what the car puts out after 20 years of use.

Also - these modification HP gains are not necessarily concurrent. In other words if you do a K&N filter install and also a chip or exhaust mod then you can't just add up the probable hp gains for a total gain. Every time you change something related to spark/air/fuel it changes the total equation and a subsequent mod might make more or less of an impact to total HP.

Excellent points on all counts Josh!

Thanks for all the good info. I replaced the dme relay like you suggested and brought the 944 back from the dead, one problem now, the tach quit working, any idea where I should start looking?

thanks,
figurenine

PorscheDoc, I'm want to purchase my first 944, and I'm looking at two different cars, a 1986 944 and a 1984 944. What I want is a 944 reliable enough to be a daily driver, which I can slowly modify into a track car over an extended period of time. I'm not picky about aesthetics, I just reliability in the drive train, brakes, steering and suspension.
The 1986 944 is stock except for some suspension mods (from 944 turbo), with a stripped interior, no A/C, oh and a diff. from turbo. The owner claims it's been well maintained, but I worry because of a knocking sound from the engine. Doesn't sound like a valve problem, though. Knocking aside, the engine sounds good, idles well, starts up well. The clutch grabbed way late off the floor, at almost full release, but the owner said that was due to a dog-leg clutch pedal. Clutch grabbed well, though, just late.
The 1984 944 has an MSD ignition, cone air filter and upgraded torsion bars. The interior is mostly there. The owner tracked the car a bit. I got to test drive it. Starts up well, idles well. The car pulled well on the road, the brakes didn't fade while driving, but I needed to press very hard to stop hard. Clutch was in good shape. Steering felt heavy, but I associate that with the age.
The 1984 944 is about $600 more expensive than the 1986 944. Which 944 is the better choice do you think (best assessment from the info and years of cars)?
Any opinions are welcome, btw. Cheers

-Apex King

Well concerning the clutch issue in the 86, IMHO the owner really doesn't know what he is talking about, lol. More than likely the disc is thin and the clutch fork is extremly worn or bent or has a master clutch cylinder that needs to have the adjusting arm moved. Some cars release high even after a new clutch, and can be adjusted some via the arm on the clutch master cylinder.

The early 944's are fun because they are so light. The late 944's are nice because of the interior improvements, rear torsion carrier updated to an aluminum system, plastic fuel tank, etc. The steering issue in the 84 could be because the power steering is low on fluid, pump shot, or maybe he has converted back to a manual steering rack. The cone filter on the 84 should be removed and replaced with the stock air box. The stock airbox is much more efficient at bringing in cold air. The cone filter, while bringing in more overall air, brings in hot air, which doesn't help the hp.


Do either have any maintenance history of clutch repair or timing belt/waterpump being done? Those are 2 expensive issues that are nice to have done already.

PorscheDoc, thanks very much for the advice. I have asked for the maintenance info for the clutch and timing belt/water pump on the '84 944. The seller of the '86 944 seems very discouraged by his attempts to sell it, because now he is considering crushing it and selling it for scrap. What is the chassis/body worth alone? Hypothetically, what could I expect to pay for an '86 944 with no interior, very rust-free chassis/body (assume it's straight) but not paint pretty, decent suspension, and a drive-train with some potential problems? If I can snag this '86 944 at a good price, I want to. Cheers.

PorscheDoc, I figured I'd let you know the asking prices for each car. The '86 944: $2500. The '84 944: $2850. Cheers.

I would offer $1,000 tops on the 86, and maybe $2,000-2,500 on the 84 depending on overall condition. With that being said, I know the cars very well, am in the business so my parts connections are very good, and do all my own work. You can't afford to pay a shop to work on a $1,000 P-car, it will break you financially. I have seen it happen to many of my customers, lol. There is nothing more expensive than a cheap Porsche. I advise first reading the book "The Gold Plated Porsche" to anyone considering buying a cheap Porsche.

PorscheDoc, thanks again. I bought "The Gold-Plated Porsche..." and so far it is has been an encouragement to say the least. The further I read into the book, the more I want a project Porsche ("light" project to start, more serious later). A $70,000 frame off restoration is more than I have in mind; more my speed, something pretty close to the lines of a reliable (not pretty) daily driver to start, and competative track car to finish. Hopefully an '84 944 will fit the bill. I'll try to finish the book before I make up my mind to be on the safe side, but I'm leaning hard towards the 944. Thanks for the insight.

-Cheers

If you are interested in turning an early 944 into a street/DE/track car, check out the NASA SPEC 944 forums. Those guys are building track cars on a pretty tight budget (obviously you don't need a full cage or anything on a street car), but they have some affordable ways to upgrade the suspension, etc.

www.944spec.org They have a forum as well.

Replacement motors for an '84 944's headlights and windshield wipers are expensive. Are there cheaper alternatives? I was thinking of buying cheaper electric motors (somewhat related to the jobs they will perform) that will get the job done after some custom wiring and fab. Thanks.

New 944
 

I am thinking about buying a 1985 944 is this a good choice i think it is but i would like a second opinion? is there any thing i should know like are parts hard to find anything like that? THANKS:confused:

anyone know if a turbo system out of a 951 will fit with the engine in the s2? or should I buy a bigger turbo for the bigger engine?

thanks

Chris

88 v 84
 

This may be a stupid question but is the motor the same on an 1988 and 1984?
looking to buy a 1984 to fix my 1988.
Thanks

The 84 motor is a lower compression motor with less horsepower. Either repair yours or try to find another engine from an 88, or I think you might be a little disappointed. Unfortunately, with the NASA 944 SPEC racing series being very popular, everyone is swiping up the 88 engines for the higher compression pistons. You would also have to swap out of a few of the sensors, use the 88 wiring harness, etc. It would work though.

Thank you very much. I'll fix mine.

more power out of a 85.5 944 na?
 

PorscheDoc, thanks for this list I found it very helpfull but still would like to ask, it sounds like the best I can do with a 85.5 944 na is to add a header (no cat) and stock muffler (or flow through but I do not want it to raspy), Max chip, and K&N in the stock air box for maybe a 15hp gain? for under $1000, with out cracking the motor for a cam or other $2k plus add ons and big bucks
did I miss some thing? any other suggestions? I love the 85.5 944 (sorry I do not like the turbo nose or rear valance, of the turbo no offense) so if I do all this and do not feel it is enough I will probably do a 968 motor and slowly change out the drive train/suspension over time.
any help would be greatly appreciated
James

Yup, that's about it in a nut shell. Upgrade the suspension to koni's (you can do paragon products koni conversion very easily and fairly affordable), maybe put on a set of turbo sway bars, and have some fun! If you really want to have some fun with the car, get associated with your local PCA and sign up for a driver's education event at your nearest road course, then you can see what the cars will really do (as well as really improve your own skills in a control environment at speed).

clutch problems
 

OK I have a 86' 944 turbo with some clutch problems. When the engine is on and running the shifter will not put the car in gear at all. I think that the sync is keeping it from that, but it will let me start to put in reverse (which will start to grind). When I have the engine turned off, I can put it in any gear I want without effort. If I start the car in gear (with the clutch held in) it will jerk in the direction of the gear. I was fine three days ago and now this happened. I have checked the brake/ clutch reservoir to make sure it is full and also drained and changed (which was kind of low and dirty) the transaxel fluid also. The shifter has always been a bit loose and doesn't feel any different, nor does the clutch. Could bleeding the clutch lines help? or does this sound like much bigger issue? :confused: I really love this car despite the problems I have had. Any suggestions will be welcome

Sounds like your clutch disc is toast. Could be the throw out bearing or pressure plate, but more than likely it is the disc.

Thank you for such a quick response. I will look into changing them out, and hope it's not a bad job to do myself.

Can anyone help me out? I have been searching on google and I cannot seem to find the FRWilk chip anywhere! I have an 84' 944 and i was reading somewhere that people who got theirs chipped helped tremendously with the vibrations that came from having your A/C on while you were stopped. Thanks for any help!