Steve,

I really think if you could get a MAF to market for 1k or less it will be a big seller.

Are you working on one?

That would be nice.

Has anyone dyno'd mufflers like M&K, GHL, etc?

This is really a bad news. All I have is a turbo muffler and a drop in K&N and I already set off many car alarms when going into the parking structure. If I cut off my air box cover and get rid of my cat, I might set off the building's alarm. :D

Steve, have you ever test between stock cat and euro pre-muffler?

I'm not sure I'm getting it right, but this doesn't seem like a straight comparison of "stock" engines.

That test would be to take a stock Carerra, test with stock airbox cover, then test with no airbox cover.

But from what I could see, you altered the chip tuning for the tests.

So it's not really a comparison between "stock" engines. To me, "stock" means unaltered, including unaltered chip tuning.

Did you run any straight tests? I.e., stock engine, stock chip, with airbox cover, and stock engine, stock chip without cover?

I am not speaking for Steve, but I think it is a little cost prohibitive for Steve's client to remove their OEM cats. You see, the shop charges for the time on Dyno and Waiting for the client to make adjustments or swapping components, especially removing their CAT trouble free ( rusted bolts/nuts) and install may take too much valuable Dyno time.

From my understanding, his clients just want the final HP results.

I have been there when he had a couple of problematic cars that was not in top shape, half the time was trying to fix the issues, i.e. rubbing tires :eek: or leaking vacuum hose. The shop use to not charge but they changed their policy due to some customers taking advantage of shops time making repairs at their facility even borrowing his tools ( now come on ) when it should be done before the Dyno.

If Steve wants me to be the Guinee Pig, I am willing to do a OEM (Brown Wire On/Off?) to Present Chipped, Pre-Muff and Cut Air Box, Wink Wink :D

Jim

A while back I had put on a MSDS type intake with a cone filter along with Steve's chip, a cat delete and Fabspeed muffler. Steve had advised me to removed some of the material inside the flange of the MSDS connector that bolts to where the air box use to be making a larger more direct path for the air flow. No dyno was done but the car sounds awesome and better pedal response. Placebo! maybe but I like it.

Excellent study and I'm sold. Obviously we see the improved difference and the proof but I'm curious of how fresh the 89 test car is to get those results.

It would be interesting to see another stock indentical model year with similar mileage could do. As for dyno results tests on bikes, one could take a pampered stock superbike with say 4-5K miles on it and its a dog compared to some with 15,000 beaten and whipped on miles.

I might be an oddball for my curiousity, but back in those days I sold and drove many new 911's. That gave me a feeling of the slight differences in the naturally aspirated cars. I'm sure after break in it's a different story.

What are the dangers of water ingestion (without carrera tail) from rain w/ little to no cover on the air filter?

Agreed McLovin. But I think we're all in agreement that the 100% *STOCK* setup is a difference of night-and-day alone when switching to just the baseline chip Steve offers. This is like going from "good" to "awesome".

Steve's test as shown is much more accurate than the test you suggest as the AFR's were corrected with each setup. This eliminates the power changes because of incorrect mixture and is the only way to properly quantify a component's impact.

Steve's test clearly and accurately shows the power loss created by the stock muffler and airbox regardless of the total numbers.

A lot of people cut open their airbox and leave the chip stock.

Steve's test doesn't show if doing that increases HP, does it?

Nope, and i doubt that was his intent.

What you suggest is very easy to do, why don't you go to the dyno and post the results?

Some of you dudes can never be pleased...........

He did an apples to apples comparison by correcting AFR's........

Well, hat we really need is a double blind test of all possible combinations published in a peer reviewed article in a nationally recognized science journal.

I'll happily contribute $1.00 if anyone cares to take up the task.

hi Steve, interesting thread. do you have any contacts on the east coast who could dyno tune a car with one of your chips?

ill put 50p in

Well, I was there when I witnessed an increase of 5 HPs by simply removing the air box cover and leaving the OEM filter, we were surprised :eek:

Mine has just SSI and muffler Dansk , Magnecor ignition wire , and when i cutted the airbox cover , i noticed a little difference : better sound evidently , but also a better throttle response , and perhaps a bit more power.

My ECU is stock.

My AFR is correct , a bit too rich.



I can hear a sort of whistle since this modification of the air cover box , like a turbo , due i suppose to the air admission.

http://i36.servimg.com/u/f36/13/86/10/18/30_05_10.jpg

Whistling is a bi-product of an open air box. Just think of it as an almost Turbo :D

It could be also coming from your Idle Adjusment, the o-ring may have shrunk a bit due to heat and age. Check by lifting the engine lid and blipping the throttle, I bet if you put your finger on it and if it wiggles you can change the sound it emits.

Jim

OK ..I didnt see where the question of combining the two tests (remove stock box cover and stock muffler) were addressed...would you expect a combined HP gain?

someone asked early one and someone else said it was addressed but I couldnt see that either

BTW I am pulling off my cover today and driving around with a bungee cord!!!

(help for the blind reader here :p)