What's the ideal fuel/air ratio in a TDI?

mojogoes

Top Post Dawg
Joined
May 1, 2003
Location
england
TDI
mk3 tdi golf
I don't know if i have said this before on this thread but the type of fuel you burn in a compression engine can make a lot of difference in how much performance the engine makes along with the amount of smoke output proportionally ..................We've only hit the tip of the iceberg to where we can achieve greater power and mileage to what we are using at present.

Manufacturing processes and Compounds that still keep a very high fuel density but while also highly oxygenate the fuel have already been produced some years ago! way beyond that of the regular and some exotic bio fuels!!

The truth is , is that these super diesel fuels will probably never see the light of day as it would be un-fortuitous for the manufactures to do so..............Somewhat like creating the perfect light-bulb......................Which we all know??
 
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hajes

Active member
Joined
Jan 16, 2017
Location
Earth
TDI
Skoda "Hilda" Octavia HR I
The best AFR is what you can keep it cool !!!

DETAILS THERE >>> https://www.hajes-racing.com/en/afr-air-to-fuel-ratio-for-tdi/

A typical eExpert, tuner wants wants anything below 18:1...they do dyno runs, masturbate by fancy graphs. But those guys can't drive and never experienced motorsport fever, heat soaking and they have no idea what full load means.

Pros and racing guys use 19-22:1 because even with "perfect" design you struggle to keep your engine cool at full load.

One of the eExperts who taught me engine calibration used 15.8:1...guess what I killed turbo in about 20k km (less than a year) :-D Of course if you are typical Johny McShopping, by all means use theoretical stoichiometric 14.5:1 because you never drive your car at full load for extended periods of time

It always impresses me that amateurs say "smoke-free" at anything below 18:1...I wonder why they have completely black back of their cars...unsure whether they are blind or just retarded. I'm smoke free too because I have DPF but it regenerates every 50km with poor calibration below 18:1

I can't keep cool 18:1...over summer 19:1...it looks great on paper but by the end of high-g fun, you have no torque thus power ;-) EGT limiter kicks in so eExperts change EGT limiter because they somehow believe 750C is bollocks and manufacturers are idiots.

internet is full of myths and misunderstanding. I never understand why Johny McGarage thinks he can do it better in garage without any equipment and knowledge ;-)
 
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m1ketdi

Veteran Member
Joined
May 18, 2009
Location
Leam
TDI
Leon BKD
The best AFR is what you can keep it cool !!!

DETAILS THERE >>> https://www.hajes-racing.com/en/afr-air-to-fuel-ratio-for-tdi/

A typical eExpert, tuner wants wants anything below 18:1...they do dyno runs, masturbate by fancy graphs. But those guys can't drive and never experienced motorsport fever, heat soaking and they have no idea what full load means.

Pros and racing guys use 19-22:1 because even with "perfect" design you struggle to keep your engine cool at full load.

One of the eExperts who taught me engine calibration used 15.8:1...guess what I killed turbo in about 20k km (less than a year) :-D Of course if you are typical Johny McShopping, by all means use theoretical stoichiometric 14.5:1 because you never drive your car at full load for extended periods of time

It always impresses me that amateurs say "smoke-free" at anything below 18:1...I wonder why they have completely black back of their cars...unsure whether they are blind or just retarded. I'm smoke free too because I have DPF but it regenerates every 50km with poor calibration below 18:1

I can't keep cool 18:1...over summer 19:1...it looks great on paper but by the end of high-g fun, you have no torque thus power ;-) EGT limiter kicks in so eExperts change EGT limiter because they somehow believe 750C is bollocks and manufacturers are idiots.

internet is full of myths and misunderstanding. I never understand why Johny McGarage thinks he can do it better in garage without any equipment and knowledge ;-)
750c is bollocks :eek::eek:
 

Macradiators.com

Veteran Member
Joined
Nov 2, 2015
Location
Romania
TDI
2.0 CR 360hp
I wanna see you make huge power at 800 egt ..impossible.
It's all LIES , or sh:t power.
I've heard a good one 2.9 boost @5200rpm with 790c egt on 2.0 CR LOL
 
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Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
I wanna see you make huge power at 800 egt ..impossible.
It's all LIES , or sh:t power.
I've heard a good one 2.9 boost @5200rpm with 790c egt on 2.0 CR LOL
Who said that? i didnt keep up on this thread, yea there full of it lol, i dont make decent power until 1300 at the lowest, full power is at 1400 ish, but thats with a 2 stage water injection system too. Planning on using NOS to get it lower with more power!
 

IndigoBlueWagon

TDIClub Enthusiast, Principal IDParts, Vendor , w/
Joined
Aug 16, 2004
Location
South of Boston
TDI
'97 Passat, '99.5 Golf, '02 Jetta Wagon, '15 GSW
I think the only thing significant about this thread is that I'm still driving the same car as I was when I originally posted 10 years ago.
 
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[486]

Top Post Dawg
Joined
Mar 1, 2014
Location
MN
TDI
02 golf ALH
fun fact, leaner isn't always more efficient

long ago nordberg made stationary diesel radial engines, naturally aspirated, enormous things run by guys raised during the great depression. Sized for full load, instead of turbocharged for full load, meaning at low load you're moving a lot more air than is needed.

If your building had a stack it was expected to have a haze coming from it. When you run a boiler you throttle the air so there's just the slightest hint of brown smoke coming out the flue, this tells you that you aren't wasting extra heat moving unneeded air up the stack wasting heat. Any air that passes through the flue is carrying with it some amount of the heat, so you only want to provide enough air to burn the fuel and no more.

anyways back to nordberg, they came up with a very early form of variable valve timing for throttling the intake air
If they used a throttle plate, they would be running the engine against an intake vacuum, negating some or all of the fuel savings from the reduced waste heat.
Instead they would hang the intake valve open a little longer and have it push some of the air back out the intake valve.

The result? Some increase in the emissions when measured in PPM, but less wasted heat pumped out the exhaust.

What you can take away is that yeah, you do get your best fuel efficiency right up near stoich. There will be some wasted air away from the injector if you calculate it out with modern instrumentation like your MAF and calibrated fuel system, but going by exhaust smoke, best BSFC is found with the slightest of smoke.
 

sam-

Veteran Member
Joined
Oct 1, 2008
Location
Belgium
TDI
Golf mk3 tdi AFN
He probably mean the possibility for members to like a post, a bit like those Thanks button on some sharing forum.
 
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