1990hondacrx

this should help u get 118mpg lmao
http://ecomodder.com/blog/20-yearold...l-economy-run/

DPSJosh

How can he run that lean without detonation? E85 and no timing? Supercooling the combustion chamber? :-D

OneBadTurboCRV

Honestly, I have no clue... I will search for his thread and post it up when I find it. Either way if you look in the forced induction forum he talks about it in his Sig. I am pretty sure it is a huge secret. Actually I know for a fact he posted in the "What wideband is best" thread (not actual name of thread but close). He was trying to find a wideband that went leaner than 20:1 (as you know most go from 10-20:1). Regardless, I am sure his manifold glows red LMFAO...

EDIT: What I didn't know is what type of fuel or how much timing he is running.

0ne-Cam

N3va3vaSatisfi3d ... I been reading your comments since you corrected me about the aftermarket FPR, but were on the right page on this one, you stated correctly that good MPG is all about the tune. What about adding aftermarket (non power-adder) parts and having it tuned for good mpg?

OneBadTurboCRV

Yes, that could easliy be ascertained. Adding parts will help, to an extent, but as talked about before there would be no real gains recieved with out a tune. The reason being the motor would be trying to compensate for the non-stock part. Some changes may not even make the ECU to need to make corrections. If you tune a motor lean but make it more efficient mechanicaly, then detonation could be avoided with the same fuel.

What power adders did you have in mind? You had a good idea with the FPR, but that would not be a good way to go about putting less fuel to the cylinders. You have to remeber as well... the motor is not always going to be at 20:1 AFR. The key phrase was "crusing speed". This is where you see mileage, not when you are flooring it at WOT.

0ne-Cam

The power adders im talking about are bigger intake manifold (i.e ITB's?) for more air to enter the cylinders and burn off all the fuel, causing the o2 sensor to lower fuel consumtion, o2 sensor is on the exhaust so a different catback/header for the exhaust flow. As for the engine internals, make it a ALL MOTOR (non boosted) high compression, close to 13:1?. doing all this to a small engine, like a D series, would be the best with a tune. just my .02

DPSJosh

I got the solution....

E85, 10 degrees base timing locked out with no advance, 35:1 AFR, 7.5:1 compression, running liquid nitrogen in the radiator. 120mpg!!!!


Edit: I have an AEM on my trans am, it's digital but I have no idea what the AFR goes to, lol. If I see it go much past 13, I get pretty scared.

~sp33~

ITB's have got to be some of the most inefficient ways of measuring fuel into a combustion chamber.

DPSJosh

Nah, just throw 4 MAFs on the stacks!

OneBadTurboCRV

Hmm... My stock LS is mid to low 15:1 at cruising speeds. 13:1 is pretty rich to never go any leaner. I would hate to see what WOT is... 10:1 or something rich as hell?

4drEF

Stock exhaust manifold is heavy and very restrictive compared to even a cheap eBay header. If this car is going to be on long freeway trips rather than street driving with stop-and-go's then the header would be a benefit. Otherwise, as posted before, the O2 doesn't heat up properly for MPG.

Best compromise would be an OEM D16Y8 manifold. Much better design for flow than the HF 'log'.
Maybe send out your injectors to have them cleaned and balanced... but I'm not sure it's worth the money. It will pay off in the long run... long long long run maybe if they aren't in that bad of condition to start with.

Everything else I'm thinking of requires you to tear the motor down - like balancing internals and port matching. Really not looking cost effective, but again... long long long run.

How about a complete proper tune up... and then drive like a grandma and stay off the gas pedal?

OneBadTurboCRV

Then how are they supposed to hit "VtAk"? Thats what I thought... Hmmm, I just thought about something...

Nobody has ever hit VTEC in 5th gear and lived to tell about it.

P.S. Yes, I know HFs do not have VTEC...

0ne-Cam

But why would you want to hit vtec when OP stated that this would be a daily driven car? I have a built b18a1 high comp pistons, cams, valves, valve springs, etc.. i get about 44 mpg normal driving but if i invested into a d series, than mpg would be alot different, i believe? someone agree with me?

OneBadTurboCRV

It was just a joke, LOL... He said drive like a Grandma and I said how are they supposed to hit VTEC. It is commonly accepted that old people drive slow.

If you are getting that high MPG then stick with it. That is good and you still have, well for what it is, power.

4drEF