Miata scroll supercharger (homemade setup) - Page 5 - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


Supercharger Discussion For all you misguided souls.
Sponsored by:
Sponsored by:

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 06-08-2012, 04:16 AM   #81
Junior Member
Thread Starter
 
Join Date: Aug 2011
Location: France
Posts: 62
Total Cats: 0
Default

Do you suggest me to rescale the AFR table to 100kpa 135 170 200 like before ?

I'm located at 550meters or 1804 feet above sea level.

Here's the spark table, it's the original table gave by megasquirt, I didn't touch it yet. I prefer to finish the VE table first.



Nice, I will keep in mind your timing table and I will adapt it to my boost curve later.

Today it's rainning and the car is tricky on the road with the new big torque^^
Attached Thumbnails
Miata scroll supercharger (homemade setup)-image_10.jpg  
phenixmt is offline   Reply With Quote
Old 06-08-2012, 05:56 AM   #82
Junior Member
Thread Starter
 
Join Date: Aug 2011
Location: France
Posts: 62
Total Cats: 0
Default

I found this comment on msextra forum:

"i understand in a supercharger the elevetion has effect on the boost out put because it doesnt have a boost regulator (like a wastegate) a supercharger will give an engine less boost into an engine because now its trying to push thinner air.. but boost is boost it shouldnt remove fuel or have baro correction while on boost.."

I not sure to understand but I don't need to set 92kpa in my target table because MS is already correcting the barometric difference? So I put back 100kpa?
phenixmt is offline   Reply With Quote
Old 06-08-2012, 10:33 AM   #83
Senior Member
 
Join Date: Aug 2008
Location: Baton Rouge
Posts: 700
Total Cats: 17
Default

Quote:
Originally Posted by phenixmt View Post
I found this comment on msextra forum:

"i understand in a supercharger the elevetion has effect on the boost out put because it doesnt have a boost regulator (like a wastegate) a supercharger will give an engine less boost into an engine because now its trying to push thinner air.. but boost is boost it shouldnt remove fuel or have baro correction while on boost.."

I not sure to understand but I don't need to set 92kpa in my target table because MS is already correcting the barometric difference? So I put back 100kpa?
A superchager will pump a (roughly) fixed volume of air for every revolution. Its output is linked to the crank speed, so if the air is thinner it pumps less of it. A turbo, not being married to crank speed, will pump more air at higher elevations.

You dont need set your cell to local baro pressure IMHO. MS uses interpolation for lookup in the ve and spark table. This means that even if the read value is in between your cells it will calculate a value in between them.
golftdibrad is offline   Reply With Quote
Old 06-08-2012, 04:50 PM   #84
Moderator
iTrader: (11)
 
sixshooter's Avatar
 
Join Date: Nov 2008
Location: Tampa, Florida
Posts: 15,633
Total Cats: 1,559
Default

^Yes what he said. If your engine is working halfway between two cells the computer will use halfway between the two values in the boxes. This makes it smooth. There is no reason to change the kpa numbers.

The spark table is good and safe which is what you want right now since the last engine blew up. It could make a little more power with more spark but it is more important to be safe right now. It is good not to need to be worried about it and just enjoy driving the car.
sixshooter is offline   Reply With Quote
Old 06-11-2012, 05:52 AM   #85
Junior Member
Thread Starter
 
Join Date: Aug 2011
Location: France
Posts: 62
Total Cats: 0
Default

Ok thanks for your comment. It was what I needed to know.

Do you have some chrono on 0-60mph of your supercharged miatas?

1.6 Stock N/A is around 9.7 second from what I know.

I also notice my duty cycle is kind of high, at 5000rpm, I got 70%

Fuel pressure is only 30psi, I will raise it to 36psi and go further in rpm.

Last edited by phenixmt; 06-11-2012 at 06:37 AM.
phenixmt is offline   Reply With Quote
Old 06-11-2012, 10:03 AM   #86
Moderator
iTrader: (11)
 
sixshooter's Avatar
 
Join Date: Nov 2008
Location: Tampa, Florida
Posts: 15,633
Total Cats: 1,559
Default

Does your fuel pressure rise with boost? It should.
sixshooter is offline   Reply With Quote
Old 06-11-2012, 10:12 AM   #87
Junior Member
Thread Starter
 
Join Date: Aug 2011
Location: France
Posts: 62
Total Cats: 0
Default

Quote:
Originally Posted by sixshooter View Post
Does your fuel pressure rise with boost? It should.
oh yes of course. I wanted to say, my FPR is set at 30psi.
phenixmt is offline   Reply With Quote
Old 06-11-2012, 05:37 PM   #88
Moderator
iTrader: (11)
 
sixshooter's Avatar
 
Join Date: Nov 2008
Location: Tampa, Florida
Posts: 15,633
Total Cats: 1,559
Default

Mais bien sur, lol.
sixshooter is offline   Reply With Quote
Old 08-01-2012, 11:26 AM   #89
Junior Member
Thread Starter
 
Join Date: Aug 2011
Location: France
Posts: 62
Total Cats: 0
Default

I have no idea of the power and no idea how long my setup will last but, for the first track test, I had so much fun and no trouble with the car.

http://www.youtube.com/watch?v=YCmKK...ature=youtu.be
phenixmt is offline   Reply With Quote
Old 09-24-2012, 12:57 PM   #90
Junior Member
Thread Starter
 
Join Date: Aug 2011
Location: France
Posts: 62
Total Cats: 0
Default

Update:

+
500miles done, 2 track days, no trouble.

-
injectors are out of flow approaching 6000rpm.


So New injectors + high flow fuel pump are comming


Attached Thumbnails
Miata scroll supercharger (homemade setup)-di-h3ud.jpg  
phenixmt is offline   Reply With Quote
Old 09-24-2012, 02:42 PM   #91
Destroyer of Inconel
iTrader: (37)
 
EO2K's Avatar
 
Join Date: Apr 2010
Location: In ur driveway, abusin' ur WPA
Posts: 9,642
Total Cats: 954
Default

Congrats man! How are the IAT's looking now?

For injectors, check out the Bosch EV14 units. They require adapters but they are pretty much superior to everything else on the market with regards to flow and deadtime. They are a bit pricey though. FIC (Fuel Injector Clinic) and ID (Injector Dynamics) are known good suppliers for the bigger EV14s. I would avoid FiveOhMotorsports though, their quality control seems to be a bit hit or miss as of late.

Good used RX8 yellow or blue Denso style injectors can also be good budget choice. They are direct drop-in IIRC, but be aware that there are really cheap chinese knockoffs out there now, especially on eBay.
EO2K is offline   Reply With Quote
Old 09-24-2012, 03:36 PM   #92
Junior Member
Thread Starter
 
Join Date: Aug 2011
Location: France
Posts: 62
Total Cats: 0
Default

Thanks!

My IAT's are around 85 F on road and I never saw more than 120F on a track day with 90F outside temp

About injectors I have already ordered DW 800cc as I would like to avoid the use of adapters.

You have Bosch EV14 or RX8's on your car?


I plan to go E85. I guess 800cc will be enough, right?
phenixmt is offline   Reply With Quote
Old 09-24-2012, 04:23 PM   #93
Elite Member
iTrader: (2)
 
triple88a's Avatar
 
Join Date: Apr 2006
Location: Chicago, IL
Posts: 9,131
Total Cats: 598
Default

Something about your map reading the wrong pressure with the engine off.. essentially this makes no difference as far as your tunning is based on that error. Just make sure you look at the numbers when you take psi into account. For example Map sees -1 psi when its atmo. You hook up your sc to push 10 psi but the map sensor should only show you 9 psi because of that calibration error.

As far as air temp goes, super chargers are fixed to the crank so any cooler intake charge will allow more air to be pushed into the engine because cooler air is more dense. Same thing as higher in altitude. Higher altitude, less pressure, less dense air.

For SC cold air intake makes a bigger difference, for turbo.. not so much. How many psi do you want to run on the 800cc injectors?

At 1800 feet you should be at 95kpa absolute air pressure.
triple88a is offline   Reply With Quote
Old 09-24-2012, 05:04 PM   #94
Junior Member
Thread Starter
 
Join Date: Aug 2011
Location: France
Posts: 62
Total Cats: 0
Default

You are right, I notice that air temp and altitude have a huge effect on the supercharger.

Exemple: on a warm summer track day, i have got 10psi at 5000rpm and last saturday night it was 10psi at 3700rpm (MAT was 77F)

So, I planned to find or make a cold air intake stuff.

I'm a at 92-93kpa engine of.


PS: between 10-12 psi, it will depend how many the G-charger could supply

Last edited by phenixmt; 09-24-2012 at 05:20 PM.
phenixmt is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
3rd Time's a Charm...hopefully. zephyrusaurai Meet and Greet 2 09-28-2015 11:59 PM
Another Alternator thread ihiryu General Miata Chat 9 09-28-2015 11:22 AM
another noob kr307 Meet and Greet 1 09-26-2015 11:33 AM
Koni 1150 Coilover Kit drumman83 Suspension, Brakes, Drivetrain 2 09-25-2015 08:03 PM
starting issue Johnny Tater Engine Performance 3 09-23-2015 07:10 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 02:09 AM.