Looks like your intake is robbing some of your extra boost, especially at high rpm.

Important note: The above is an apples-to-cheese comparison.

 

>>Important note: The above is an apples-to-cheese comparison.

*snicker*

That's funny right there...

 

Andy,

Do you have temperature measurements for those graphs? It would be really cool to see the temperatures at the various pressures.

Right now everyone is just measuring the elements around the true information which is how much oxygen is getting into the engine.

 

I logged this data long before the pulley was the cool thing to do. This is how IAT varies with RPM. The graph doesnt show the temps, only the change in temps from a baseline, which varied on every run. (i did this during the summer)


The different lines indicate different filter setups.

The stock is uhh stock.
The foam consists of me removing he airbox lid and placing a foam cylinder there, similar to the ALTA but without the shield.
K&N, same deal as foam, but with an oiled cotton filter.



--
Cheese

 

Cheese,

Thanks for the numbers. I was really looking for temps after the supercharger. This would allow a calculation of the amount of air getting into the engine

 

>>Cheese,
>>
>>Thanks for the numbers. I was really looking for temps after the supercharger. This would allow a calculation of the amount of air getting into the engine


I'm pretty sure IAT is measured in the intake manifold.

--
Cheese

 

>>Looks like your intake is robbing some of your extra boost, especially at high rpm.>>

Looks like that pesky hampster problem again.

 

Here's boost and IAT for 3 different runs I did during lunch. All of these are on my car, 15% pulley, intake, exhaust. Ambient air temp was 0 degrees C.

 

What gear were you in? I'd imagine first would generate the highest temps due to the intercooler getting less cooling air at lower speeds.

And what order where they run? I'd guess they'd get hotter succesively, but you have run 1 listed as the hottest.
_________________
'04 MCS IB/W on order with SSR's wrapped in Yoko's ready to go on!

 

All these runs were second gear. Even in the run with the greatest fluctuation in temperature, absolute temp only changed by 4.4% (298K -vs- 311K).

 

Great - thanks for posting this information!

 

WTF, you guy's can get all this information about temps and preasure but no dyno numbers....

 

I've already dyno'ed my car with its current setup. Click on the Dog's Bollocks.
_________________

SHOW ME THE NUMBERS! 1/4 Mile Database

 

>>folks,
>>finally pulled the trigger.
>>i am a new soon-to-be owner of a 04MCS (just placed my order last week).
>>
>>i have been perusing this forum for awhile now and i find the pulley mod to be the most fascinating mod for my upcoming MCS.
>>two questions i have about the pulley change:
>>1) just wondering about the gas economy tradeoffs in going to any of the pulley reduction schemes.
>>2) i have seen threads about changing the ECU chip.
>>any serious downside to not making the change?
>>
>>appreciate any light those of you in the know can shed on this matter.
>>
>>a mod newbie,
>>-spirit16-

Average MPH 63.6

Average MPG 27.6

and i expect MPG to go up after adding ECU.

Earl

 

>>folks,
>>finally pulled the trigger.
>>i am a new soon-to-be owner of a 04MCS (just placed my order last week).
>>
>>i have been perusing this forum for awhile now and i find the pulley mod to be the most fascinating mod for my upcoming MCS.
>>two questions i have about the pulley change:
>>1) just wondering about the gas economy tradeoffs in going to any of the pulley reduction schemes.
>>2) i have seen threads about changing the ECU chip.
>>any serious downside to not making the change?
>>
>>appreciate any light those of you in the know can shed on this matter.
>>
>>a mod newbie,
>>-spirit16-

Average MPH 63.6

Average MPG 27.6

and i expect MPG to go up after adding ECU.

Earl

 

You're results don't necessarily say much b/c there's a big difference in average speed. Although the pulley does increase gas mileage, I find that in the 60mph range my MCS gets the best mileage.

 

Scurves,

were your dyno readings taken at the same dyno & elevation?

 

Thats for 17%.... I left Mr Paperclip in there because hes my other hero (sorry jlm)

--
Cheese

 

Cheese,

What gear were you in & what was the ambient temp?
Thanks!

 

I just did some more logs as well. It looks like Cheese's 17% has just about the same delta T as my 15%:



Ambient temp was 2 C.

 

Andy,

Based on your numbers and cheeses (if they are correct), the maximum boost difference is only .5 psi, and the temperature difference is not to far off. Although when cheese temperature drops in relation to yours, the boost drops as well. Very interesting.

Your sampling rate doesn't look so good, compared with cheese, so it is not so accurate. Looks like you may have only taken 13 or 14 datapoints. Is this correct?

I would still like to see an absolute temperature as well. So it looks like the overall boost doesn't affect much and the extra spin is still not putting out much more heat than the 15%. Also, boost is still climbing at 7,000 rpm indicating that the supercharger still has more to give, although the temperatures are starting to overtake it. Now if we can just get a 19%. I think it will show more midrange boost but will still come near 16 or 17psi boost because of temps.

 

Im not going to mention the apples to oranges comparison again, but does Cheese have an intake, i noticed in your notes, it says just exhaust, just a curious question, and yours does have an intake correct? Are the ambient air the same? I also want to mention since you always attack my findings, i dont think you realize that several factors make my car vary from others, i have done intake modifications, i do use my hood scoops, i do have a moddified head, custom exhaust(header included),diffrent cam(BBR not shrick), different injectors, etc, etc, as you know all these mods play a role in power, as well as the tested variables, simple, better air path can increase the effeciency of the supercharger allowing more boost. I never did say that the boost is what everyone should expect, just that it is what i got......

 

dgszweda1 wrote:
What are you basing that on? Both my data and that of Cheese, have 27-28 datapoints between 2k and 7k rpm. :???:

Absolute temperatures vary based on driving conditions leading up to the runs. I'll post up a spreadsheet with the raw data and a CFM calculation.

 

Caddman,

Feel free to read or re-read the rest of this thread, then comment appropriately. I think you'll find the answers to many of your questions.

 

Caddman,

You may appreciate this:

:evil: