Performance Add-Ons That Don't Work

[Apache]

In reading through the posts here and at some other boards, I'm starting to get the impression that there is precious little that you can do to legally up the power output on a 944/924S 2.5 Liter motor.

Is that correct?

I was wondering if we could list some of the performance enhansements that did not live up to their promise.

Of course, if you have something that works, let me know that too.

[AFJuvat]

Actually taking an 944 N/A motor and modifying it to push over 300 HP is entirely possible, but it just is not economically viable to do so - for the money spent (well into the thousands of dollars) you could have bought a much faster car to start with.

Example: Buying 944 Euro pistons and Euro DME: about $4000 US. Net gain, 22HP

Let me start by saying all of the reputable performance upgrades for sale DO work, but usually not quite up to the manufacturers claims.

One of the biggest stumbling blocks to upgrading the 944 engine is the DME itself - It constantly monitors air intake, air pressure, engine temp, engine speed, and in the US, emissions, to create the optimal fuel/air mix at a given load.

Any performance upgrade has to blend in with the system so the proper fuel\air mix can be maintained. The DME can alter its profile to account for greater airflow or greater fuel flow etc, but only so far.

Any upgrade that introduces fuel or air into the engine that isn't accounted for by the DME can result in an over-rich or Over lean condition = poor performance and\or engine damage.

Therefore, since the biggest stumbling block is the DME, lets look there first:

Chips:

Autothority chips seem to have a good reputation, driven a few cars with them, the cars seem a bit faster no hard dyno numbers though.

One user here, FRWilk, makes a custom chip for the 944 - Heard lots of good feedback, but I do not have first hand experience with them (Hint Hint FR!)

Airflow:

Changing to a cone filter or putting in a K&N filter - Will make the engine breathe a little better - A bit more power, but I have serious doubts about the claims of up to 15HP just by changing an air filter. 3 - 10HP is more realistic, with numbers coming in on the lower end of the scale

Porting the throttle body allows more air flow, you decide if 1 - 3HP is worth the $300+ to have it done though.

Exhaust:

If you increase airflow into the engine, you should make acomidations to increase airflow out of the engine.

There are a ton of aftermarket exhausts out there, some good, some bad, all have their pros and cons. Have personal experience with Bursch and B&B - both are high flow and did give the engine a little more oomph.

Overall, the most reasonable upgrade I have seen is a quality chip,a high flow filter, and a good exhaust - with a little shopping around, it is obtainable for around $1000 or so.

Other consideration: Maintenance. Poor spark, worn distributor, worn coil, exhaust leaks, etc: all can rob the engine of power

AFJuvat

[Sternn]

Don't forget, painting stripes, adding neon underneath, and buying a huge ass wing for the back always helps increase the HP by about 100% as well!

-S

[TCMdocs944]

Nice post AFJ.

Should be an update to your faq

I have been contemplating the same upgrades you speak(post finishing my valves) but I kinda feel like something is going unsaid.

Don't bother upgrading until you know how your car truly should run. Clean, inspect, adjust, gremlin chase, and when you finally have everything the way it was intended, bring on the upgrades.

Does the "chip" only negatively effect fuel efficiency or does smoothness and ride suffer as well?

Will the chip take care of any low exhaust pressure problems due to not having a cat?

[924Sman]

I found the only way to gain speed is to hook up a tow rope and get pulled by my buddies GT4 911! hehe Sman

[CJFusco]

"One user here, FRWilk, makes a custom chip for the 944 - Heard lots of good feedback, but I do not have first hand experience with them (Hint Hint FR!) "

Do they work on early cars?

"There are a ton of aftermarket exhausts out there, some good, some bad, all have their pros and cons. Have personal experience with Bursch and B&B - both are high flow and did give the engine a little more oomph. "

Don't forget about headers. A combination of B&B Headers and Exhaust WILL increase performance A LOT. But you will pay hand$omely for it.

"Changing to a cone filter or putting in a K&N filter - Will make the engine breathe a little better - A bit more power, but I have serious doubts about the claims of up to 15HP just by changing an air filter. 3 - 10HP is more realistic, with numbers coming in on the lower end of the scale "

A K&N filter WILL give you a power increase - just remember that you are replacing a DIRTY and USED filter with a brand-spanking new K&N filter. Replacing any worn-out part will increase performance; for example, I replaced my ratty old plug wires with some high-quality Jacobs blues, and the difference was actually noticable.

"Overall, the most reasonable upgrade I have seen..."

Is making the car lighter and improving the braking and suspension.

[RIchard944]

Originally posted by CJFusco
"One user here, FRWilk, makes a custom chip for the 944 - Heard lots of good feedback, but I do not have first hand experience with them (Hint Hint FR!) "

Do they work on early cars?

Yes, I have had one in my 84 for about 2 years now. The difference is night and day. You will need to add one of his boards first. Richard

[CJFusco]

interesting. How much for the board and chip, and how difficult is installation?

[Roger Hall]

Originally posted by CJFusco
interesting. How much for the board and chip, and how difficult is installation?

I think the chip is $200 but check here. I have no experience but FR Wilk is a fellow board member and verry knowledgeable. I would not hesitate to purchase his chip. Problem is it wont do much siting in the glove box of my 924.


http://frwilk.com/944dme/

[todwic]

Originally posted by RIchard944
Yes, I have had one in my 84 for about 2 years now. The difference is night and day. You will need to add one of his boards first. Richard

aye! You can see my unsolicited testimonial on his site. I posted it here, just to say "hey guys, this is the shizit!" and F.R. asked me if he could post it on his site. I'm am about to take 0 - 20, 0 - 60, 0 - 100, and top speed times/speed with my stock chip and then with the power prom chip. I might po$t the re$ult$ here, if $omething motivate$ me.

[Porsche944]

So you want more power, huh? Well, who doesn't?

It has been stated previously that there doesn't seem to be much that can be done for the NA engines without spending a boat load of cash, and for the most part that is true.

However, there are some things that can be done to improve the vehicle's performance.

First you need to consider the mechanical condition of the engine. Dropping $200.00 on a chip for a "tired" engine is a waste of money, so make sure the engine is healty. IMHO, this is where the biggest gains will be realized.

Second you need to consider your local emission standards, taking into account any restirctions those standards impose.

Once you have those two items taken care of you can start with the "upgrades." Forget cone filters and test pipes.

Cone filters are designed to pass more air, and to do that the size of the passages in the filter media are significantly larger than the passages in a stock paper filter. From a purely air flow stand-point this is OK, but you have to take into account that larger passages in the filter media means that larger particles of dust and dirt are allowed to enter the intake tract.

To compensate for this fact the filter manufacturers recommend spraying the filter with an oil based product that is supposed to trap the dust and dirt. Horse pucky. Once you start the engine any excess oil that has not soaked into the filter media is immediately drawn into the intake tract. Since the purpose of the oil is to help the filter media trap dust and dirt, the oil in the intake tract is wasted. IMHO the "performance gain" isn't worth either the risk or the increased maintenance required.

Test pipes are another waste of money. The big problem here is the engine was designed to operate with a certain amount of exhaust back pressure. By installing a test pipe you remove some of that back pressure which causes a noticeable drop in low end torque.

Replacing the chip in the DME is perhaps the most cost effective modification, and there are several vendors that make chips for the late model DMEs, as well as Mr. Wilk who offers a chip and adapter for the early model DME.

Although I have not tested one of Mr. Wilk's production run performance chips in my '84 (I beta tested one of his chips for a late model), I have modified the DME and installed one of his adapter boards with a "944 Shudder" chip. IMHO, this "upgrade" is not meant for the average DIY mechanic because you need to have very good soldering skills and good quality tools.

I am fortunate in this regard because I have a complete soldering/desolderiing station in my work shop, and during my career in the US Navy I was a Miniature/Microminature Repair Instructor/Certification Inspector. Even then I ran into a couple of problems performing this upgrade.

However, there is another alternative for the early model ('83 to '85.0) engines: Replace the DME and AFM with parts from an '85.5 or '86. This is a "Plug-and-Play" upgrade. You do not need to modify the harness, or make any other changes to the engine, and you can install a performance chip. You need to replace both parts because the early and late model parts are not electrically compatible with each other.

I have done this to my '84, and the improvement was dramatic to say the least. Before doing this upgrade my '84 had this annoying habit of stumbling during hard acceleration, particularly if the electrical system was loaded (head lights, fog lights, A/C, and/or rear window defroster running).

With the '86 parts installed the '84's engine purrs like a kitten, has plenty of power, starts every time, and never misses a beat.

[Frank B]

tilting your seat back adds a ton of Horsies, and so does putting duct tape with holes cut in it over your brake lights. Oh and listening to really bad music adds extra Horsies too. also revving your engine at old ladies in malibu's and Falcons adds a few HP if you scare them enough. Also driving like a complete ********* adds alot of Hp to anycar......

[Moneyguy1]

Cliff: What is an AFM? I am pretty familiar with the earlier models and (forgive me, it's late and I ain't thinking straight) but are you referring to the Air Flow Sensor switch? When I go to Pick A Part I want to make sure I am stealing the parts I need!!!

[overkill]

You can tell AF loves what he does Well done.

[Porsche944]

AFM= Air Flow Meter. Sits between the air box and the intake boot. Sorry for the confusion.

[Roastin944]

Everyones had good experiences with FR WILK but all i have to say is watch out! Mine didnt work at all so i sent it back and he says the post office lost it, the post office never loses something!!!! Beware!

[todwic]

Originally posted by Roastin944
Everyones had good experiences with FR WILK but all i have to say is watch out! Mine didnt work at all so i sent it back and he says the post office lost it, the post office never loses something!!!! Beware!

The post office never loses something? You are an idiot. Worse than that, your a 16 year old idiot that doesn't insure things when he mails them so that he can blame someone else. You should learn to follow instructions and life will be a lot less troublesome for you.

[schnellfahrer]

I have dealt with Mr. Wilk. His customer service is excellent. Shipping is really quick and the chip does excactly what he claims.
I would not hesitate to recommend his products to anyone.

[COLDBASS]

Originally posted by Roastin944
Everyones had good experiences with FR WILK but all i have to say is watch out! Mine didnt work at all so i sent it back and he says the post office lost it, the post office never loses something!!!! Beware!

John,

This is so uncool...FR's products work for the ROW, I have not seen any complaints, other than yours, posted regarding his products and services...

Its a free Country, and you are certainly entitled to your opinion as Todwic and I , however, FR is well-respected here and with Folks on Rennlist. His products are solid...

Peace

FR,

If you ever decide to sell Power Prom2 T-Shirts, I take 2...

[Frank B]

Hey roastin944.
I don't believe your "story for a second"
reason #1. The post office does lose things... on a daily/hourly basis. I have a friend who is a U.S. Postal service employee.
#2. Umm.. why didn't you have the item that you paid alot of money for "insured" as to guarantee that you wouldn't lose any money just in case, it wound up in China for some unknown reason.
#3. I think you ruined the chip because you don't know how to follow instructions very well because your one of those guys that reads the instructions after he fails to just get it done.
#4. You're now out $100.00 + dollars and you're pissed off because you've fried your new chip and you're pissed off. So, act like a man and be honest.
#5 None of what you're claiming smells right. You made a mistake, handle it.

Frank B