Test... fuel cooler & fuel rail heat insulating wrap. test done on a bone stock 2001 VW jetta 1.8t (turbo'd).

Goal, to find out if there is anything to my butt dyno telling me there is more low end torque in 3/4 times that I've done this mod (the 4th was in the 2nd gen ram I had... too heavy to feel anything but gained 6.5% better hiway mileage)


Back to back runs, no cooler with fuel rail wrap



Back to back runs, with cooler with fuel rail wrap



All data compiled onto a spread sheet... copied into jpg for display purposes.






back to back runs... strapped it down, added the fuel temp sensor in line with the return line, fired it up... ran it for about 2 minutes in 3rd under load then did 2 back to back sweeps for the 1st setup. fuel rail wrap only.

then inserted the fuel cooler in line and checked for leaks... found one, fixed one (after a gas shower forgot to relieve the pressure), fired it back up and ran if for about 2 minutes in 3rd under load, then did 2 more back to back sweeps, setup = fuel cooler + wrap that was already installed.

the 3rd test which I was unable to get to as I was already approaching $200 bux in dyno time was to remove the fuel cooler & wrap and do 2 more runs.

Also, I left the J out in the sun all day to get the tank as hot as I could before going in. This proved to be a mistake as I could only get approx 10* out of the fuel. You could feel the cold side of the cooler getting cool but the rail never got down to the "cold to the touch" I experienced before I wrapped the rail (was cold to the touch after about 75 miles of mostly freeway driving in 95* weather)



Where's Hank?

 

ya want me to analyze all those graph lines for free?

please send a US Postal Money order for $1000

 

Steve,can you show me a link to the wrap and cooler that you used? thanks

its nice when you can see real numbers. great post.

 

well,
it does look like the air to fuel ratio line gets leaner
with the fuel line cooler in use,
even though the lines for back to back runs
are not 'spot on top of' each other
... agreed?

my first guess is that the slightly cooler liquid fuel
cooled the air more that it was sprayed into
and that this denser air
leaned the AFR
and brought it closer to the
12.8 to 13.2 AFR where horsepower usually peaks
but where the danger of detonation lurks

if you decide to go back to the dyno and spend more money,
some back to back runs
where you spray 50% water, 50% methyl alcohol mixture (windshield washer fluid)
into the air going thru the intercooler
might show the same HP gains
for the same reason as the fuel cooler

for safety sake
to protect your piston crowns
from detonation and instant holes in them
run all dyno tests
with the highest octane fuel you can buy locally
like Sunoco 95 octane

links you might find worth reading

http://www.snowperformance.net/

http://www.musclemustangfastfords.co...ons/index.html

http://autospeed.com/cms/A_110213/article.html

http://www.aquamist.co.uk/

 

http://store.summitracing.com/partde...5&autoview=sku

5/16" fuel injection line @ $4~5/ft

 

I think I'm confusing myself here,

I think I understand this concept on a carbed engine, but how does that work on a FI engine where the charge is essentially mixed in the chamber, giving very little time to condense the air charge? Are we just dealing with a smaller total charge, or more air to fuel in the ratio?

 

well when I 1st did this mod on a '93 bmw 325 the goal was to stop the pinging I had when using a 93 octane performance program in the pcm... I only get 91 octane here. it worked perfectly. so well that I also added it to the M3 when I switched to that. had a perf. program installed and once the cooler & wrap were added the low/mid bump was felt. I couldnt ever tell if there was an upper end bump. My thoughts at the time were to change the densitiy of the fuel, however slight it might be, in an effort to bump the afr some.