4.0 SOHC Performance Motor Build

[jah81592]

Jake that is the trims I had on my truck.LOL! Also stay away from a manual shift conversion, I vote for the auto. I agree with 2000streetrod, keep on track with your objectives and don't worry about what the forum members say. I have measured for the 4.6L dohc and I don't believe it would fit (if it would it would be really tight) in your engine bay. A 5.4L is even bigger!

 

[mr.p]

is a wastegate a must? I read all three articles and am wondering why it is necessary if the BOV is controlling the boost?

 

[mr.p]

never mind answered my own question


the turbo would just spin massive rpms when the bov opens, as the gas would still be spinning it on the exhaust side.

 

[Jakee]

Jake that is the trims I had on my truck.LOL! Also stay away from a manual shift conversion, I vote for the auto. I agree with 2000streetrod, keep on track with your objectives and don't worry about what the forum members say. I have measured for the 4.6L dohc and I don't believe it would fit (if it would it would be really tight) in your engine bay. A 5.4L is even bigger!

I guess I overlooked this?

Yes, I came to my senses.

I think a manual shift conversion would have its downfalls as well as a few benefits. I've always liked driving manuals and I like the freed up HP you get. Also, I love the 2-step sound at the starting line.

But, I'll keep what I have until it breaks.

 

[Jakee]

never mind answered my own question


the turbo would just spin massive rpms when the bov opens, as the gas would still be spinning it on the exhaust side.

Yeah, you'll overboost without a wastegate. The wastegate regulates the boost your engine see's.

A BOV is only really needed when the boost goes above a certain level (most say 8-10 lbs) and is there to vent the air when the throttle blade shuts. So if you're running 10 pounds of boost, without a BOV, and snap the throttle shut, there will be a major spike for a second, which can result in blowing couplers and stuff off. Most of all, the pressure will back-up on the compressor side of the turbo.

Compressor surge - Such a "locked-in" or self-reproducing stall is particularly dangerous, with very high levels of vibration causing accelerated engine wear and possible damage, even the total destruction of the engine

 

[mr.p]

I realize that now that i have read up on it more. It would be nice to see some dyno curves of your setup.

Did you start with a baseline tune from james or did you do all the tuning yourself?

 

[Jakee]

The baseline was done by Don LaSota and James helped tie up the loose ends.

I rewrote the entire tune from scratch for learning purposes and that's the one I'm running now. It takes awhile to learn.

 

[mr.p]

what size injectors and maf are you running? im sure its been covered before, but what about the fuel pump? also what have you changed in the transmission tune? im starting to get a flare 1 out of 10 times shifting from 2nd to 3rd about 90mph

 

[Limited02]

what size injectors and maf are you running? im sure its been covered before, but what about the fuel pump? also what have you changed in the transmission tune? im starting to get a flare 1 out of 10 times shifting from 2nd to 3rd about 90mph

What gears are you running? I didnt' know Sports could do nearly 90 in second?

 

[CDW6212R]

That must be a 3rd/4th gear shift, at 90mph. If so that's not the typical place for a flare. I think the intermediate band is engaged for that gear, and one of the clutches is grabbing to make the 4th gear. If that's what's going on, then I'd guess you may have an issue with the main pressure or the band is slipping at that point. I'd drive it easy until confirming what is causing it. Bands don't last long if they keep slipping.

You can do something about the PCM tuning of the pressure, and adjusting the bands is a wise thing to do as maintenance. I need to do that on mine as well, I've put around 45k miles on mine since going through my VB and solenoids, bands.

 

[mr.p]

the explorer shifts from 1st to "2nd" at 67+ mph the 2nd to 3rd shift occurs right around 89-90mph.

it has done it twice, fluid looks clean and with the sct it showed trans temprature to stay between 160-165 even when sustaining high speeds.

note i also have 32.5" actual diameter tires and 3:73 gears.

 

[mr.p]

sorry to thread jack but thought jakee might have some tips on what he did to the transmission to make it survive

 

[CDW6212R]

I hate to have to tell you this, but you are missing the 1st/2nd gear shift. The first gear is short, maybe 40MPH or so tops(a little higher with your 3.73's and 32.5" tires). Check it again, I hope your tires and gears aren't getting you up that high in first.

 

[Limited02]

Sorry to stray off topic, but Mr. P could be hitting 63mph in first if he has a 5R55E/3.73's and 32.5" tires. Second would top out at 84mph.

http://www.charlietranny.com/5R55E.htm
http://www.f-body.org/gears/

Back on topic- Jakee, get the damn thing running!!!

 

[Jakee]

MAF = BA2600 SCT
Injectors = 42 lbs
Fuel pump = walbro gs something or other; can't remember but it's here somewhere

With the tranny, I've increased the line pressure, set the torque reduction between shifts, changed the MPH for shifts, corrected the NV, changed from shifting with RPM's to shifting with MPH and more.

I would be driving it now but I've managed to of lost 3 bolts. 1 for connecting the turbo (the 4 bolt flange) and 1 for the wastegate.

The weather is cool enough for some good times here!

 

[mr.p]

im pretty sure jakee has the same transmission/gearing as me, if so ive figured out maybe a 4.88 gear swap would knock a second or two off your tracktimes

 

[Limited02]

im pretty sure jakee has the same transmission/gearing as me, if so ive figured out maybe a 4.88 gear swap would knock a second or two off your tracktimes

While 4.88's would be fun for a NA car, it wouldn't be best for a Turbo car

 

[mr.p]

im sure higher gears will help in any setup, due to the fact that i never get to see the last 2 gears WOT over 100mph in 3rd with 2 more gears to go seems like a waste of a 5 speed.

 

[CDW6212R]

im sure higher gears will help in any setup, due to the fact that i never get to see the last 2 gears WOT over 100mph in 3rd with 2 more gears to go seems like a waste of a 5 speed.

You need a lot more gear with your tall tires. Jake is probably about right with his as they are. I've got 4.10's in my 99 SOHC, with 29.5" tires, and I'd rather have 3.73's for my normal road use.

 

[htrdlncn]

The weather is cool enough for some good times here!

Send me a message if you go to track this winter, would really like to see
your Explorer run.
Frank