Bigger turbo means lean mixture?

Discussion of technical issues and ideas (engine, chassis)

Moderators: P3g4sus, Daniel, rat, Draco, Riekert

Guy
0.3 Bar Boost
Posts: 327
Joined: Tue May 13, 2008 8:28 am
Car: S13
Location: Richards Bay/ Durban

Post by Guy »

Gary57 wrote:Exactly, well almost, changing the intercooler will change the mass of air entering the motor and the MAF wont "know" about this.
Not really right. Conservation of mass flow means the same mass going throught the MAF will go into the engine, unless you have a leak somewhere.

All in all a lot of good info and understanding in this thread. I think the main thing that was possibly being missed out and that Gary mentioned is that of temperature.

The chemical reaction of combustion in the engine is all about mass, a certain mass of fuel requires a certian mass of air to burn completely.

Now comparing an engine set to run 0.5 bar with two different turbo setups. The more efficient turbo will heat the air up less than the inefficient turbo. Lower temperature means a greater density and for the same volume being inducted a greater mass. Therefore although both turbo's are making 0.5 bar pressure the more efficient one will have lower charge temperatures, greater mass flow, and make more power than the less efficient turbo, everything else being identical.

I personally like the ide of a MAF directly measuring the mass flow into the engine hence why I will be running the Link G4 ecu with a MAF. It can also run MAP so if MAF doesn't work out I can always switch to MAP or play around with both.
Friends don't let friends drive Honda's
User avatar
Gary57
Club Rep
Posts: 5975
Joined: Thu Oct 12, 2006 12:56 pm
Car: S13
Location: Durban

Post by Gary57 »

Yeah I also like MAF over MAP, thing is MAP is cheaper to use. Where can one get a decent MAF that will take decent power. Doesnt need to be Nissan specific...
DriftZ: "I swear if a CA18 beats my SR im getting a RB!"
User avatar
Pinkfluffybunnys
Over Boosting
Posts: 1693
Joined: Thu May 08, 2008 1:21 pm
Car: Other
Engine: SR
Real Name: Ashley
Location: Pretoria

Post by Pinkfluffybunnys »

Yeah I also like MAF over MAP, thing is MAP is cheaper to use. Where can one get a decent MAF that will take decent power. Doesnt need to be Nissan specific...
Ford Cobra MAF - 700HP Rated (If I remember correctly)
2008 Mazda 6 MPS - Daily Drive
1\4 Mile:
1993 Nissan Sentra 200STI SR20VE – Mild VE
1\4 mile: 14.815 @153km\h @ ODI --- 1KM:195Km\h

Because Race Car
User avatar
Gary57
Club Rep
Posts: 5975
Joined: Thu Oct 12, 2006 12:56 pm
Car: S13
Location: Durban

Post by Gary57 »

Any idea on a price PFB?? Also do you know of any that are more around 400hp, I would like to use the full +5v range...
DriftZ: "I swear if a CA18 beats my SR im getting a RB!"
User avatar
Pinkfluffybunnys
Over Boosting
Posts: 1693
Joined: Thu May 08, 2008 1:21 pm
Car: Other
Engine: SR
Real Name: Ashley
Location: Pretoria

Post by Pinkfluffybunnys »

z32 AFM should be good for 500HP

R1000 most of the time
2008 Mazda 6 MPS - Daily Drive
1\4 Mile:
1993 Nissan Sentra 200STI SR20VE – Mild VE
1\4 mile: 14.815 @153km\h @ ODI --- 1KM:195Km\h

Because Race Car
User avatar
djtreble
Over Boosting
Posts: 1502
Joined: Fri Jan 29, 2010 2:49 pm
Car: S13
Location: Cape Town

Post by djtreble »

Z32 is the best bet but the genuine ones are normally pretty expensive
Image

Distributor for ROTA wheels South Africa

www.rotawheels.co.za
www.kaihatsu.co.za
User avatar
POWDER
Club Rep
Posts: 1204
Joined: Fri May 15, 2009 12:19 pm
Car: S13
Engine: SR
Real Name: Mike
Location: Johannesburg

Post by POWDER »

djtreble wrote:Z32 is the best bet but the genuine ones are normally pretty expensive
Ye, I checked a while back on the SR20DET MAF price before going with the dicktator idean and they already like R1600 new from Nissan. I would not even want to see how much the Z32 MAF costs.....

So now, since u guys all like MAF, does that mean u guys don't mind the overfueling bit when using a vent to atmosphere bov? Talking if u like the dumping sound that is.....

That would drive me mad.....
Carpe Diemotor - Sieze the motor today
Image
- Nissan 200SX S13 92' SR20DET
http://200sx.za.net/phpBB3/garage_vehic ... cle&VID=14
Guy
0.3 Bar Boost
Posts: 327
Joined: Tue May 13, 2008 8:28 am
Car: S13
Location: Richards Bay/ Durban

Post by Guy »

Vent to atmosphere is pointless unless you like a car that sounds like it has a cold. Mine will be done the proper engineering way and recirculated.

Or you could do like Gary has mentioned before and run a blow through maf setup.
Friends don't let friends drive Honda's
Post Reply