My Turbo Build

[uhtrinity]

Originally Posted by mikemo

Mark,
Just curious, can you tell me what your manifold pressure is when cruising on the highway?
Thanks
Mike M.

Average of maybe 0 to -3. But realistically I see from -9 (closed throttle), to spikes as high a 6 lbs boost under load.

[Willie Williford]

mikemo?

What speed, gear, rpm are you referring to? Also altitude.
All the above will cause a specific change.

Willie

[binder]

14 is very lean under boost. Wide open throttle on naturally aspirated vehicles should be 12.5-13 and forced induction vehicles should be below 12 depending engine compression and octane of fuel.

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[uhtrinity]

Originally Posted by binder

14 is very lean under boost. Wide open throttle on naturally aspirated vehicles should be 12.5-13 and forced induction vehicles should be below 12 depending engine compression and octane of fuel.

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That is what I see with OBCIIC&C, I'm actually skeptical with that reading as the O2 sensor value fluctuates while the primary AF ratio value doesn't. I have yet to see it below 13.8. It is easily locked on 14.2 or ~22 95% of the time. I will try to take some video of it.

[mikemo]

Originally Posted by Willie Williford

mikemo?

What speed, gear, rpm are you referring to? Also altitude.
All the above will cause a specific change.

Willie

Very true. How about constant 70mph, 5th gear, level ground at sea level?

[Willie Williford]

It will probably be around 4 in. vacumn. The next time I get to sea level, I'll check. Most of my driving is around 2500-4000 ft. (I use the old fashion type gauge)

Willie

[uhtrinity]

Originally Posted by mikemo

Very true. How about constant 70mph, 5th gear, level ground at sea level?

Roughly -3 to 0psi at 5000ft.

[uhtrinity]

I thought I would post a long needed update. Everything is still running fine with a few minor glitches and adjustments.

1. I have a slow drip where I installed a tee, but it only drips when cold. Even with the spring weather it has slowed considerably leaving a drop smaller than a dime on warmup. I will tighten the tee as soon as I get the time to pull the air intake manifold off for access. As an alternative I have seen some oil taps that screw on between the oil filter and the engine. If someone could find the right size this would be an easier solution to installing a tee on the oil pressure sensor like I did.

2. I had one coolant line come off at the turbo. Wasn't a big deal to fix and top off, there was no damage as I knew something was wrong as soon as the temps jumped above normal.

3. I'm going to temporarily remove the BOV as it isn't being used. At 5 psi boost it never activates, so the two options are remove it or find one that is more sensitive. I would still recommend one for higher psi, but at 5 psi I believe it is just taking up space.

4. I should finally be installing the Injector controller and 4th injector in the next few weeks. The FMU is working fine, but I would feel better with more control over fuel delivery at boost. The FMU will then be deleted.

5. Summer will be the real test on whether I can continue to run w/o an intercooler. So far it has been fine with peak intake temps at ~150f under boost on warm days.

Winter mileage was in the 60 - 65 range (tank), though I could easily pull 80 mpg or higher on trips. Warmups however killed the high averages. My mileage was comparable to a friend with a stock mima insight. As the weather started to warm I also tried some hypermile runs and could still get into the 90 - 100 mpg range. That is with the turbo, spat cutout, and non stock rims, and stock tires.

In all I have put about 5k miles on the car since install running between 85 and 93 octane fuel. There has been no noticeable difference in either power or mpg performance between the two grades. Btw, almost all fuel here now has 10% alcohol.

[Willie Williford]

Question, ref. number 3;
You aren't mistaking the BOV as the Wastegate are you.?
BOV relieves pressure when going to a closed throttle position after "boost"..
Wastegate, limits the max. pressure the turbo will yield under "boost"..

Willie

[rickoner]

I wouldn't run without a BOV. When I first put my kit together at 5lbs I didn't have one and drove it for a few days. Compressor surge was very loud. Not a very nice thing to do to your turbo. I put a bosch bov/diverter/by-pass valve on it and the "blow off" is very audible. These come stock on vw/audi/porsche and are very cheap and reliable at low boost. One day I'm going to plumb it back into the turbo's intake. What BOV are you running? Maybe the spring in it is too stiff?