FSAEracer03

Interesting... I believe it. Throwing a cone on there isn't going to help. But I'm basically advocating the same principle he used. Force air into your pipes from a cold location. He chose to do it with the airbox in place and a dryer duct hose. I'm saying get the airbox away from the engine so that the respriction point is away from the engine by routing a conical filter up front. Shove that cold air down it's throat by boxing it off with a heat shield and seal it to the body clading. Same idea... different approach. Unless someone can show me that the stock box poses less restriction than a conical filter, let me know... but I've seen the top end power increase a good amount ($$ comparatively, of course) when a correct conical filter setup is used. Ever wonder why all the intake upgrades in Performance Products utilize funky shrouding around a cone filter? Less restriction, sufficient heat shielding and a design that seals the intake when the trunk/bonnet (what do you call that on a 911?? lol) is closed.

Predator... you seem to be the most experienced here with modding a '44. Just our of curiousity, do you think the mods I listed above would yield 170+ horses, or no?

Geo

Well, I'm not Predator, but I can say your hp increases are a pipe dream.

Talk with the 944Cup and Spec 944 guys. They have done actual dyno testing with various components. No bloody way is a chip going to get you 10-20hp on an 8v NA (at least none that are available commercially). Those guys have tested them. Headers (at least MSDS and Bursch) don't make a whole lot either. They've tested them. Supposedly the Stahl headers make a bigger difference but I cannot get dyno confirmation of this.

Dave

OK, sounds like a lot of guys here are thinking with their catalogs and not with their brains. Sorry to inform you of this but you are not going to get an honest 20 HP with a chip, a cone and exhaust mods, at best you might come close to this number at peak but with some losses someplace else on the dyno sheet. Real HP gains for an NA don't come cheap but if you look at it logically there are gains to be had.

Cones, flat K&N, CAI:Mostly snake oil, the stock filter can flow more air than the engine can ever use. The flat K&N can flow a lot more and a cone can flow a hair more than that but you don't get any HP from having a filter that can let in more air than you could ever want. IIRC, colder air makes more power at the rate of 1 HP for every 10 degrees, move north and pick up a few ponies! Cold air is better, but as ERAU pointed out, our cars came with a decent CAI from the factory. Yes the hose could be bigger, but it really isn't a limiting factor for stock cars. Placement is hard to improve upon, the stock system is located in a spot that has fairly still air so turbulence doesn't limit flow and it's also protected from sucking in large quantites of rain.
Chips:There's a few HP to be had here, the first 2-3 are almost free (just the price of premium fuel), a couple more are found at the top of the tach by upping the rev limit (or in my case by doing away with it entirely). Any chip that really does add more than 5-6 peak HP is just moving it from someplace else in the rev range, that's great if you can keep the rpm up but it sucks when you get stuck in traffic. Autocrossers OTOH, know the real benefit of a chip is in the high rev limit, a couple MPH more in second is faster than shifting to third (and then having to downshift) most of the time.
Exhaust:Again, Porsche designed a complete system and a pretty good one. Modifications here will mostly just move the torque curve up and down relitive to RPM. You might pick up a couple HP but just like the chips, Porsche didn't leave a whole lot of power on the table.

All these mods and what have you got? If your lucky, you've added 10 HP, that's assuming that your chip and your chosen exhaust work well together (I've seen losses from a chip that did not complement other mods). OK, now you've spent ~$500 anf your 150 hp 944 can make as much power as a 1988 (158 hp) what's next?
Two things I heard years ago that help me, 1) An engine is like an air pump, more air in and more air out equals more hp. 2) Just like a garden hose, your engines ability to flow air is limited by it's narrowest spot. What do these mean? It means your cone filter is making some cool intake noise but since the air filter was the fattest part of the hose to begin with, you won't see much HP from it. To make HP you have to find the restrictions and remove them.
I hate to say this (because I dislike 9xauto), but one of the biggest restrictions in the intake tract of a 944 is the AFM, so the ad is fairly truthful in that respect. Now that I've gotten that out of the way, their MAF kit is a bottom of the line unit and their price is a little more than some of the better systems. I'd want to see dyno sheets to back up that claim of 14 hp, it sounds a little optomistic, I'd guess half that much.

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Predator

I think hedders, a good exhaust (no cat) and a good chip will give 20+ hp on a good motor. Jet Hot coating will help somewhat by keeping more heat inside the pipe vs. radiating it into in engine compartment. Cooler air from outside is also better than under hood air. Any ram air help would be at speed, then a marginal amount. Most gains are from camshaft change, and then, you'd need head and intake manifold work to realize its potential. Superchargers are a great thing, and I came very close to getting the Huntley setup. Now that they're gone, I'm glad I didn't. SFR... don't know much about them, except you loose A/C on their setup. They were 're-designing' their supercharger two years ago to include A/C, but think its still 'in development'. Sadly, it all costs $$$.... how fast do you want to go? I appreciate all the purists and will probably get into a 951 soon. But $ for $, the cheapest way to super car performance with usuable hp for the street is thru the V-8 conversion. I read alot of high hp claims from the turbo guys, but 400 hp and 200 fp of torque will not cut it on the street.

dgz924s

My car has the stock box and snorkel. Half way down the snorkel is where the 2 pieces connect. Removed the snorkel to the fender and use it for brakes. SMOOTH interior tubing from the box end of snorkel to the front airdam. No way you can beat this set up.

Drier vent hose is not good as the ribbing causes turbulance.
And I don't know about all of you but it seems all the chipped cars end up on jacks more often than stock NA's Dal

schlag

Stahl headers, have not heard of those. Tell me more?

Geo

Again, given testing done by the 944 Cup guys, I have a very hard time believing this. According to a good friend of mine who is an engineer for an OEM and also an aftermarket performance parts consultat, the cam overlap (negative according to him) would tend to limit the response of the engine to a header. Dyno tests say the MSDS and Bursch don't do much. Jon Milledge specs a custom header with very specific tube diameter and length. Don't know how much better it would be, but the word is the commercially available 944 headers are not very good.

Again, I've yet to see someone put a car on a dyno to test a chip and make more than a few hp.

Don't know about the cat. Could be the factory cat sucks. I know a good aftermarket cat will have zero reduction in hp. This is from documented controlled dyno testing.

I'd rather doubt the Jet Hot coating would gain you much if anything, but Swain's White Lightning coating is a true thermal barrier coating. My turbo G20 had lower underhood temps with a Swain coated manifold, turbine housing, and J pipe that it had when NA with a header with a Jet Hot coating. That stuff (White Lightning) really works.

Cold air helps. But, instrumented testing (on other cars, but I see no reason it wouldn't hold with the 944) shows that under hood temps at speed are near ambient. This was from three different people using two different cars placing thermocouples under the hood. There wasn't enough temperature difference to create measurable hp difference.

As I've written before, the way a CAI makes power is only marginally from cold air. The main source of power is the resonance tuning of the length of the pipe. AEM determines the length of their CAIs by going to a dyno and they keep cutting 1/2" off the pipe and retesting. They use the length that makes the most hp.

People through ram air around a lot, but until you are putting positive pressure at the intake, you're not really doing anything. It's a marketing tool.

I am surprised so few people have messed with cams in the 944. They are not that awful expensive and they would almost certainly provide the biggest bang for your buck for NA power. Sadly, in the class I will be racing, I must retain the stock cam.

Geo

http://www.stahlheaders.com/Frame%20New%20RR.htm

I wish I could tell you more. I've read here that they are supposed to make noticeably more hp. But I cannot find dyno documentation to back it up. Butt dynos are notoriously inaccurate so I'd just like to find some documentation.

Matt H

My butt dyno is off by about 200HP or if you sat in the car now it is reading 0HP, about 400 short of the goal!
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schlag

Thanks for the info.

My exhaust system is in shambles. I'm still debating whether to just patch it up, or instead to work it up.

M758

Yep... Not much power out there from the current comonly avalible bolt on mods. Stahl and Milledge may produce more hp, but I have not seen it.

George is right. We in spec land have done some testing and found not much out there for bolt on stuff. We are not allowed things like new cams or port/polish stuff. Most cars run 130 to 135 hp. Here is listing a few of the most successful cars in class

944 -Dyno

Note...
The 51, 22, and 94 have all won races and own or had track records.

Bryan

I've never dealt with 9xAuto and am also not a fan of cone filters and other such fashion accessories that don't provide any real world benefits.

But the big win with this particular kit is the replacement of air flow meter with a hot wire air mass meter. Someone already stated this, but I just wanted to elaborate.

On a stock 944, either 8-valve or 16-valve, all the intake air has to squeeze through the air flow meter and hold open a spring loaded door that's trying to close against this flowing stream of air. With an air mass meter, instead of having to force open a spring loaded door, the air just whizzes through what amounts to a section of pipe. There's a smaller piece of pipe inside this larger piece of pipe, and there's a wire about the size of a human hair across it. That's it. There's effectively no restriction with a hot wire air mass meter.

In addition to low restriction, an air mass meter responds a lot faster than a flapper-door air flow meter. So I would think you'd get much crisper throttle response with an air mass meter as well.

As for the price/quality ratio of this particular air mass meter implementation, I'll leave that to folks with hands-on experience with them.

Bryan

FSAEracer03

Dave the air pump analogy is a classic, I've used it myself. The garden hose analogy is irrelevant in out discussion, however. Sure a garden hose is limited by any bottleneck, as is a motor's intake and exhaust. However, seeing as garden hoses don't resrict flow with a filter, you can't use it Think of shoving a wad of tissue in a hose and securing it. That's what an NA's intake and exhaust are like. For the intake, that wad is the filter. Put your lips to a stock paper-based air filter and push air through it. Do the same to a K&N and feel the difference of restriction. For the exhaust side, that resistance is almost all in the cat converter. Replace that tissue wad in your garden hose with a few mesh inserts and see how much more water flows. That mesh you just replaced it with (filter or racing cat) just let a lot more water (air or exhaust gases) flow, huh?

For all you electrical engineers out there; V=IR. The filter acts as the resistor in a circuit does. As resistance goes up and voltage remains the same, current (air flow) must drop. Lower that resistance and more current runs through the circuit.

As for the Spec racers... well I'm not too well versed in them, but I'm assuming to conform to SCCA rules and such that they are restricted to certain modifications... that's kinda how a spec racing series works. I'm assuming street mods could be extended and played with far further.

dgz... yeah, smooth is the answer here too... the factory snorkels in the 924s and 944s were freakin' accordians!

Exhaust coatings definitely help keep energy within the pipes, a proven method of getting an extra hp or 2. I would just assume, however, that it would be cheaper to wrap them for the same effect (unless your engine drools oil... exhaust wrap and oil drips are bad!! I've put out on of those fires before, lol). Speakig of which, I forgot to include the header wrap in my signature... thanks for reminding me

The higher redline is a great benefit, that is not arguable in the least... you just have to love it

I hope someone gets a dyno chart for one of these new Powerchips that just came out... they seem to have waaay high expectations of their chips and like to show dyno charts in their ads (I wonder if they are fabbed or not)

Geo

One great effect of the hot wire MAF is that it allows you to change volumetric efficiency (VE) over a wide range without having to reprogram your maps, unlike a AFM or MAP set-up. By measuring the voltage required to keep the hot wire at the same temp it effectively is directly measuring air mass while an AFM or MAP must use other sensor and they assume no change in VE. This would be good for someone planning on really doing an outstanding NA 944 engine.

Don't get me wrong, I don't think there is nothing to be gained from a 8v 944. Jon Milledge gets 183 bhp from a IT legal (very mild modifications) engine. However, it will take some serious committment to the task and some serious money. Jon Milledge has invested both.

FSAEracer03

very good point George... and it's for reasons like that I wonder why more MAF setups haven't been developed for the 944s and 951s. So many 951 MAP kits but so little MAFs.