Lessons Learned

[ttrainxl]

I put an 8” tube with an inlet and outlet between the brake booster and intake manifold. I notice no difference in power at all, but I haven’t gotten into the higher rpm range. If it gives me more power up there, it doesn’t seem worth it to me because I want the fuel mileage aspect of it and I don’t rev the engine that high. I was hoping for the low end torque that you experienced but I just didn’t get it.

I’m leaving the tube on for now to see how it affects my fuel mileage for this tank, but I’m also testing my grill block off at the same time, so it’s not a fair test. Maybe I should remove the tube, refuel, reset the trip meter (again, no fuel mileage instrumentation), and just drive several days or around 150 miles and see what the results are when I refuel and do the math.

Gotta install my MPGuino! But don’t have a good mount for it. The mount it came with doesn’t work well.

[steve05ram360]

So you have the tube inline with the brake booster? Mine is off a T to the booster so the line to the booster is close to the same length. I have a hard time believing it would make a difference, inline vs a t. Maybe experiment with different lengths... I did find that length matters on the 4.7 v8 i have. What car/engine is yours?

Today i added the 2.5" exhaust valve to the airbox and got what i expected, valve opens way to quick and the response is similar to having the snorkel off, shift in power. Have to come up with away to slow the actuator down, the power shift was identical to what i experienced on the ram, valve opened too quick giving the performance of the open air box. I added a bleed valve to slow boost to the actuator. Not sure how to get that done with vacuum.

I will report back the jeeps results when its done. (3.8l v6)

[steve05ram360]

I installed the 2.5" vacuum controlled exhaust dump valve on the air box yesterday and got just what I expected... bottom end torque dropped off. The valve starts to open at something like 15 inHg, I need to find a way to change this so it opens at ~10 inHg.

I am open to suggestions...

While I did not do any datalogging, one thing stood out on the drive into work today was the vacuum signal off the MAP seemed to be higher on the flats near the port... (nothing is flat around here except that area). I expect a drop in mpg's doing 60 on the work commute. What I am shooting for is a shift in torque up the rpms under heavier loads at higher speeds.

Will see how the mpg's pan out as is 1st though (prior to trying to adjust the control of the valve)

[ttrainxl]

I am trying this on a ‘95 Honda Civic with an economy 1.6L vtec engine making 125hp and about 106lb/ft torque. I might try different vacuum tube lengths since the end caps aren’t glued in yet. I can’t seem to post a pic of my setup. My phone isn’t acting right when I try the attachment. I’ll try in another post.

How are you measuring all this data? Vacuum and torque shifts and whatnot? I’m not sure why having a reserve of vacuum in these tubes would shift torque lower and/or make more torque. I think I should understand the principle before I start spending money on something. This didn’t work for me and I can play with it and see if I can get better results since I’ve already spent money on the supplies to do it, but adding more vacuum tubes would require me to buy more end caps and I don’t want to do that without seeing results or understanding why this works.

I think I’m not completely clear on your exhaust valve mod on your air box. And what part are you referring to as the snorkel? Are you piping hot exhaust gas into your intake? If so, where are you pulling this from? Don’t you have EGR that pipes it into the intake manifold or something? It seems going into the air box would put gases and unburned fuel all over your map or maf sensor and cause problems.

I think you’re a little ahead of me in understanding the relationship between all these things.

[ttrainxl]

Oh, there’s the pic at the bottom. Not sure if you can see it well. Clicking it on my phone is useless. It shows up way off center on the screen and touching the screen at all closes the box, so I can never see it.

[steve05ram360]

Using Torque to monitor the engine... I think what is going on is the ECM is advancing timing based on manifold vacuum. This engine does not have a MAF sensor which may be holding you back if yours has one. Since you felt now power difference and it is not giving you reduced power I'd leave it for a few tanks and see how mpg's pan out.

Minimally, you should get a roll of exhaust wrap and use it to insulate your fuel rail and intake manifold. If you do it get the white stuff (cheapest), it is easy to work with and it does the job expected. I took a piece of sheet metal and a chunk of this stuff placed on it, used a heat gun to heat up the sheet metal and then looked at it with a thermal cam & the area behind the wrap was definitely cooler than w/o.



Mini Cooper I owned after I wrapped the fuel rail



2.5 valve installed... Need a shield between the air box valve and the engine still...







As I stated earlier, this gave me a reduction in bottom end torque but a bump in the mid range power I want to get that bottom end torque back along with the mid range power so I'm going to add in a bleed valve in-line with the actuator. The goal is to get it to start to open later then what it is now. Power wise it is nice but I am a torque junky with having the Ram and its bottom end torque dialed in. FWIW, the ram also has the turning vane & a 3.5" valve with a velocity stack on the bottom of its air box. (may have shared that pic already)

[ttrainxl]

I’m not very tech savvy but I’m guessing Torque is an app for the phone. I’ll look into it. I don’t get how it would know all these things about the engine without being connected somehow to the ECU or all the sensors.

My Honda doesn’t have a MAF sensor. They all use MAP sensors, so no issues there. I thought MAF sensors were more of a domestic thing, but I guess they don’t all use them. It seems right now I’m getting pretty good fuel economy, despite a couple highway trips and a little city driving (I get worse economy on the highway than I do on local roads). Might be in line for about 45 or 46 mpg on this tank, up from 43-44. Again, I’ve added the grill block off as well, which I think might be most of it since I didn’t get a low end torque bump. I think I’ll get down to a half a tank, refuel and see what economy I got, remove the vacuum tube, and drive another half tank and see what I get then. The half tank is fairly arbitrary…. I just want an average over a couple hundred miles instead of a handful of trips.

[steve05ram360]

I use this bluetooth scantool... not sure who makes one for obd1.

https://www.obdlink.com/products/obdlink-mxp/

There should be data on the grill block for your car here on ecomodder, maybe someone will add in on it. Since your motor is as small as it is, you might not need the tube to be that big. You'd have to experiment with it to understand how it affects your motor.

I forgot to mention (I think...) the whole motivation for adding the tube was to smooth out the vacuum fluctuations in the intake manifold. The 1st attempt got me the big bump in the bottom end torque. Recall this motor is a 4.7L V8, smaller motors may be harder to detect torque changes by the SOTP. I was shocked at how much added torque there was on the bottom end. I already knew that flow thru the air box would give better upper end performance so it makes sense to do the 2.5" valve.

I have 2 aero mods on my plate for this truck, 1st being the 2nd air dam under the radiator. Did this with success on the Ram so it should do well on this truck. Then the 2nd is to make a tailgate spoiler that has the flow separation pointed at an angle back into the vacuum bubble that is there. The goal being to cut it down some to reduce that drag.

[steve05ram360]

bleed valve installed on the control line to the 2.5" air box valve, now have most but not all of that bottom end torque lost with opening up the box for the valve. The valve is closed now to around 10 inHG of vacuum. On the drive into work I had CC set (vacuum controlled on a cable throttle body) and it could not hold speed up one of the ~2 mile 400' grades at the 62 I'd set, looked down and speeds had crept up to 65 mph. I would bet if I'd be willing to go back to the stock TB (current is bored to 70mm, stock is 65 or 68mm iirc) it would have an easier time under greater loads holding speed... but I'm not.

So now I have a good compromise between the closed air box torque and the open air box mid range hp.

The only thing left that I'd do is insulate the remaining vacuum lines and tube ends, otherwise this has run its course.

[steve05ram360]

Just did a 150ish mi road trip for a pickup, zero eco driving with speeds in the 63-73 mph range, 19.497 mpg... Shocked it was that high, was expecting 16.5 or so... Will have to check but i think that might be my 3rd best tank on this truck. If not 3rd, 4th for sure.