doug,
I would be happy to 1/4 mile drive your mini! :smile: :smile: :smile:

 

>>Casey,
>>
>>Very interestiing, but I have a few questions as well....
>>
>>1. I notice that you are running the larger, more efficient water/air intercooler on that car. What about running the 19% pulley on a car with the stock intercooler, can the stock intercooler keep uo with the extra heat load?
>>
>>2. Are you running colder spark plugs with the 19% pulley, and if so how many heat ranges colder? I would think you would have to in order to keep detonation under control.

We have not used any colder spark plugs on any of the cars yet and have had no need to. Yes with the 19% pulley it will generate more heat...we are also testing this pulley on a bone stock car with intake only...but we want to wait a bit longer before posting the results of that..so far no problems..but we want to wait to see over a longer period of time first. I'll keep you updated.

 

Casey,

Props to you for actually putting a product through its paces before making announcements and/or putting it up for sale. Keep us informed of what's in the works in the future.

Cheers!

 

Casey,
Glad to hear you are testing it on a car smiliar to mine. I have stock exhuast and I am running a K%N typhoon intake and stock plugs. Glad to hear plenty of research is being done. Testing new stuff is fun :smile:

So far the 17% pulley has shown me first gear accelration is very powerful. With temps in the mid 50's (Intake air temps in the high 60's) the car pulls very strong and wants to break the tires loose as the revs rise. While roling at 3k in first gear and mashing my foot to the floor the tires will break loose. I checked 2nd gear accelration buy coming onto a highway at 1000 rpm and the car gets up and goes nicely. 5th and 6th gear acceration from 3k rpms is nice it has a little more power than with the 15% pulley.

TheChandler
If anyone wants to join me I will be at Englishtown on Friday night to see what she runs.

 

>>
>>TheChandler
>> If anyone wants to join me I will be at Englishtown on Friday night to see what she runs.

Be sure to post your results

 

Casey,

Thanks for the reply....but it wouldn't be me if I didn't ask a few more questions .....

1. What are you doing to help with the extra heat load on the stock MCS, Red Line Water Wetter in the coolant or something?

2. Why do you think colder plugs are not required? I ask since another reputable tuner I have used on my M3, Turner Motorsport, sells a kit with colder spark plugs (albeit with a 15% pulley).

3. What octane gas are you using? I am assuming that since ProMini is located in TX you are using 93. It does not really matter to me since I have access to 93 octane, but I am sure the boys in Cali would be very interested.

4. I know your 19% pully is still in the testing phases on the stock MCS, but how many miles do you have on it and what type of miles (i.e. daily driver miles, track miles, etc..)

 

>>Casey,
>>
>>Thanks for the reply....but it wouldn't be me if I didn't ask a few more questions :smile:

>>
>>4. I know your 19% pully is still in the testing phases on the stock MCS, but how many miles do you have on it and what type of miles (i.e. daily driver miles, track miles, etc..)

on the stock car all street (though we all drive like we stole it so I wouldn't say they are really daily driver miles - more like very aggresive street miles)...no track...on blue thunder both track and street.

 

Casey, I bet I have you beat for blower speeds - I've seen 7691 engine RPM at the dragstrip (special chip) with my 15% pulley for a calculated 18,639 blower RPM. Here's an interesting chart showing air pressure versus blower speed:

 

andy@ross-tech.com,

Tthanks for posting that graph. It looks like the boost just continues to build - I would have expected it to start dropping, but I guess the supercharger is more efficient than I thought. I wonder what kind of power was being made as a result of the likely increased intake temps....

 

darnit, if i had more notice, i would actually ditch work and drive to PA for that, in my book totally worth it!.

I have been able to get my 60' times consistantly 2.30-2.39 now. good burn out(turn the wheel when spinning the tire to evenly heat up everything) and dump the clutch at 2.5k or so and i have been hooking up like wild fire... yoko es 100's. Having to shift to 4th really hurts the times though (but trap speeds are through the roof :smile

 

Well I am running real crappy 60ft times 2.7 or 2.8. I will be drag racing in Englishtown NJ on friday as long as the weather is nice. I want to see what this pulley does for me at the track even if my Drag skills are not that good.

 

How much boost are you runnin?

 

I'd love to be there but I'll be trick or treating!

 

I can not really tell since i do not have a boost guage. It should be between 16 and 17psi from what it did in another car. I am waiting for my guage mount and I will get a gage hooked up when I do

 

Casey,

I must say that I am impressed. My MCS is barely 2 weeks old and I have been looking into pulley upgrades. Your 19% pulley looks very prommising, I just hope all of your testing goes well.

The colder plugs was not for extra power, but rather to help out with detonation that can occur with increasing boost. I would imagine the colder plugs would be recommended for the guys in Cali since the best they can do is 91 octane.

But alas, 2 more questions.....

1. I know stock max boost is around 10.5 psi at 6900 rpm (based on what I have read since I do not have a boost gauge in the car) and that a 15% pulley will get up to around 15 psi or so. Where is the 19% getting to?

2. So far, I like the Turner Motorsport kit the best since it allows me, the consumer, to program the car (i.e. I do not have to mail in my ECU). More importantly, if the dealer inadvertently flashes the computer during a service call, you can easily flash it back. Will you be able to provide something like this or will the ECU always have to be sent to you?

 

>>andy@ross-tech.com,
>>
>>Tthanks for posting that graph. It looks like the boost just continues to build - I would have expected it to start dropping, but I guess the supercharger is more efficient than I thought. I wonder what kind of power was being made as a result of the likely increased intake temps....

Well, the supercharger will keep making boost as it is spun faster, but the issue becomes heat. Some of the boost is due to increased air temperature rather than a greater number of air molecules. At WOT, from 2k to 7k rpm, intake air temperature can easily go from, say, 90 F to 160 F. Since PV=nRT, the absolute change in temperature will be proportional to the absolute change in pressure, if all other things are kept constant.

For temperatures in Fahrenheit, you need to add 460 to get temperatures in Rankine.

So, look at a change from 550 to 620 Rankine, it is an increase of about 13%. So a large amount of that boost especially at high rpm is really due to heat, not additional air molecules.

 

>>So, look at a change from 550 to 620 Rankine, it is an increase of about 13%. So a large amount of that boost especially at high rpm is really due to heat, not additional air molecules.

Ahhh, that's what I figured. So you really do start to see diminishing returns at those levels of boost.

As mentioned earlier by others, it appears the real benefit of the 19% pulley would be to shift the powerband to lower rpm's, not to really increase the top end. It would be cool to see some dyno charts...

 

Hey Doug,

Sounds terrific.
Enjoy it...as I know u will :smile:
I'd like to drive your..... newly pulleeeeed MCS..... and compare it to my ride.

BTW.... b4 I forget... next time I cya ..please give a broken piece of the black fender flair ...or any piece that you can spare...as I have someone who wants to paint it as a "test"

Cya soon


Peace,
D
>>Well I spent the day down in Philly, I went to Geno's and had a cheese steak and the headed over here for some desert

>>This was the desert tray :smile: Yummy :smile:

>>Now since I have already tasted the first 2 (stock & 15%) for 24k miles I thought the third one (17%) was the way to go
>>Thanks again ERIC.
>>
>>I will leave a full update after it stops raining and I can test out the new found power. The car ran excellent on the three hour rain soaked drive home.
>>
>>Am I the first to run 17%?????
>>
>>_________________
>>Doug
>>
>>
>>When in doubt, Choose the burrito

 

Parallel conversation.

 

From the parallel conversation - a new belt of course is used...but that is a minor item. Additionally it isn't totally about more boost - it is about moving the boost to more usable rpm ranges. We have been testing this for months, including track time and have had zero problems with water pump. About the supercharger redline - zero problems so far as well. But again the the rev limit could be set slightly lower and the usable power range would be better and it would still would not pass the redline that the 15% gives, but you would have a better powerband. Have you actually tested a 19% pulley? We have been for months, we didn't just talk with others about it, we installed it and beat the crap out of it. We do not sell parts that are unsafe...every part we sell is throughly tested. The heat issue also falls into the same as above, if you want to run a slightly lower rev limit the boost will be the same, the heat will be very close, and the power band will be better. We are not talking about running 20psi of boost, we are talking about boost available at a wider range...if you want 20psi of boost we have a turbo for that :smile: We have also had zero problems with the gearbox and the added torque.

 

Casey,
I love all the info about this. I think allot of people are worried about over reving the charger But I do not spend allot of time at redline when I am cruising around town or on the Highways. I spend most of my time at 3k rpm's.

_________________
Doug


When in doubt, Choose the burrito

 

What is "CHT"?

 

>>What is "CHT"?

Cylinder Head Temperature

 

Ah, makes sense. I see EGT measured more often.

 

We have been looking closely at the effects of a 17 and 19% pulley for quite some time, and I'll add these comments to what has already been volunteered.

The waterpump issue has been much discussed in conjuction with reduced-sized pulleys. The opinion is that there is a risk of inducing cavitation from impeller vacuums. In the considerable time that I have worked with impeller and PD pumps, I have never seen any evidence of this happening with the kind of speed increases that we are talking about. Take for example a typical SCCA GT5 rabbit. the motors are routinely built to reline at 2200 over stock. They utilize the stock water pump to no ill effects.

With a 19% pulley, we are seeing boost pressures around 17.5 pounds on a dyno run up to 6500 rpm. We have seen no unsusual EGTs or wierd wide band O2 readings. We also monitor the ECU with a OBD2 scan tool looking for unusual numbers. So far, everything looks good. Ultimately, our goal is to do extensive dyno and road testing. That's why we have put a couple of smaller diameter pulleys out there. Stay tuned for more info, either at http://www.helix13.com or call us (215 739 8800 for our latest propaganda. -Eric