7875 + 5.9 + E85 + Megasquirt

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I took the car to the track last week and have a new challenge. I made three runs total, all shitty. First two were 7.70s at about 95mph and slow short times. I pegged the shift light the entire run and the log showed I was hovering around 6300 rpm the whole pass. This was at about 12 lbs psi. So on the last pass I turned off boost control and just ran off wastegate spring which was around 7 lbs psi. I went slightly faster, 7.60 but dropped about 1mph and only hit 6000rpm. I’m either blowing thru the converter or the trans is slipping. I changed fluid and filter, adjusted the bands and it’s about the same on the street just running off the waste gate. Next step is to probably drop the trans and rebuild and send off the converter or get a new one.
 
That sucks! How did the fluid look? If it’s happening in every gear I would think the rear clutches might be toast. I’d be interested to hear if it’s the converter as I don’t really know the symptoms of that type of failure…
What have you done to build the trans, and what valve body?

Any improvements in blowby?
 
turbovan said:
That sucks! How did the fluid look? If it’s happening in every gear I would think the rear clutches might be toast. I’d be interested to hear if it’s the converter as I don’t really know the symptoms of that type of failure…
What have you done to build the trans, and what valve body?

Any improvements in blowby?
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The fluid looked great, smelled fine. It was practically brand new anyway.
The pan had a little bit of junk in it but nothing crazy. It still shifts firm going through the gears but IDK. If I’m going to pull it to service the converter I think I might as well pull it apart and inspect everything and replace clutches, etc. I bought it already built by somebody else. It has a RMVB in it. An old TCI I think and its been a great trans so far.
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I’m with 85glht. When you take power out and pick up .3 and only lose 1mph that screams converter is too loose. I’d rather it be too tight and just try to smack it in the *** on the 2step to overcome it trying to drag the motor down that way you’ll have good slip numbers in high gear.
 
turbovan said:
Any improvements in blowby?
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Yes the oil catch can coming off the pan seems to have done the trick. It’s also a great heat vent from the engine. There’s some serious hot air venting out of the engine through it.
 
Sounds exactly like you’re blowing through the converter. What fluid was in the trans? You could try hygard and see if it tightens up the converter if you just had atf in it.
 
New converter installed. Got this from a buddy who had it as a spare. It’s a Circle-D supposedly and was built for an oddball — LS turbo mated to a 727 in a Dakota. It’s a little tighter than my PTC and has much better street manners and flashes to about 3200rpm. Now that I’m able to couple the HP to the trans and back to the rear tires, the difference is incredible. Feels like I was slipping 100hp in the old converter. Oh, I've been using Hygard (Lucas equivalent) @TT5.9mag for a while now on my trans. I love it. Just add enough ATF to give it a watermelon juice color so you can read it on the dipstick.
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This was earlier today. 3rd gear, rolling into boost on the street. The old converter was blowing right past this and hitting as high as 6300rpm. This one is holding steady. Can't wait for next track day. :)
Also my new Ford Contour dual electric fan and PWM controller is working like a champ. It's a hot and humid 96F today in S. Florida and cruising temp stayed below 180 and creeped up as high as 190 at stops.
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subcom said:
This was earlier today. 3rd gear, rolling into boost on the street. The old converter was blowing right past this and hitting as high as 6300rpm. This one is holding steady. Can't wait for next track day. :)
Also my new Ford Contour dual electric fan and PWM controller is working like a champ. It's a hot and humid 96F today in S. Florida and cruising temp stayed below 180 and creeped up as high as 190 at stops.
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Excellent!!
 
Awesome news!
9.5 converter? Is it flashing to 3200 under boost, or is that stalling it on the brakes? I’m curious because my 9.5 is supposedly setup as tight as possible; brake stalls to around 3200 and flashes to around 4800 at full boost.

I, again, know very little about converters. Is this something that wore out slowly over time as opposed to breaking all at once? I’ve been wondering what’s holding your new build back as I believe the old motor/turbo went 109 in the 1/8th?
 
The electric fan win is great too! I was a bit confused why my car was staying cooler than yours in similar temperatures(minus humidity) even though my block is half filled.

What are you using for a pwm controller or how is that set up?
 
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turbovan said:
Awesome news!
9.5 converter? Is it flashing to 3200 under boost, or is that stalling it on the brakes? I’m curious because my 9.5 is supposedly setup as tight as possible; brake stalls to around 3200 and flashes to around 4800 at full boost.

I, again, know very little about converters. Is this something that wore out slowly over time as opposed to breaking all at once? I’ve been wondering what’s holding your new build back as I believe the old motor/turbo went 109 in the 1/8th?
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This is all early days in the testing but I’m judging the flash based on where it starts to build boost in 3rd. It might be even tighter on the brake but I haven’t tested. No expert on converters either but it’s possible my old PTC is just overdue for a rework. I’ll send it back to them and find out. It was a great converter behind two different motors, NA and boosted.
 
turbovan said:
The electric fan win is great too! I was a bit confused why my car was staying cooler than yours in similar temperatures(minus humidity) even though my block is half filled.

What are you using for a pwm controller or how is that set up?
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So it’s the Ford Contour dual fans which are inexpensive, compact and move a lot of air. The PWM is from a Mitsubishi dual fan application and the latest MS3 firmware provides granular control of the fans. So fans are off until 170 and then I add 40% duty cycle and it ramps up to 100% at 180. I also have it set to cut the fans at 40% TPS so I’m not taxing the electrical system during a run. So far, so good.
 
Got it to the track tonight and made three runs, last one is a new personal best. 6.82 @ 106.5MPH at 13psi and no two step, just foot brake and no boost at launch.

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This was my first pass. The 2-step was acting stupid and didn’t even turn off until I was well out of the hole killing my 60’ but MPH was strong. This new converter is tight and didn’t allow me to build boost on the line so need to adjust the 2-step to match the converter. This was 9 PSI.
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2nd pass. Turned up the boost to 10psi and disabled the 2-step. Would have been faster but I let off short of the stripe cause my shift light came on and I panicked and let off the gas like an idiot.
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Awesome mph! What rpm are you seeing for brake stall and how much boost?
What’s your 2 step strategy?
 
turbovan said:
Awesome mph! What rpm are you seeing for brake stall and how much boost?
What’s your 2 step strategy?
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Without the 2 step I just brought the RPMs up to about 2700-2780 before launching. That wasn’t enough to build any boost. The 2-step when it worked with the old converter is programmed to cut timing to 1 degree and add fuel starting at around 2500 RPM. This usually would allow me to build about 3-4psi on the line.
 
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subcom said:
Without the 2 step I just brought the RPMs up to about 2700-2780 before launching. That wasn’t enough to build any boost. The 2-step when it worked with the old converter is programmed to cut timing to 1 degree and add fuel starting at around 2500 RPM. This usually would allow me to build about 3-4psi on the line.
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Nice! I WANT to play with mine more. I “watered down” the hy-guard in my transmission with atf+4 to gain about 200 stall rpm bringing me to ~3200. I’ve gone into the negative degrees, but still hit the hard limiter which I don’t believe is desirable? I’ve not messed with hysteresis enough. It just builds so much under hood heat so quickly, and the limiter feels borderline violent. It’s fun, and I’d love to mess with it for hours, but it just doesn’t “feel” healthy for the setup. Plus I can’t put that power down from a dig(street) anyways; 2nd gear rolling 2step hits are a blast though!

Any idea if testing the 2 step is as rough on the build as it seems? Or does it just feel that way?
 
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It’s been really great to see your build progress with test results from the track. You’ve conducted a massive amount of R&D for our community and I’m extremely grateful. I haven’t gathered the balls to run mine at the track yet for fear of breaking something, but I’m dying to see what it will do. Someday…

I don’t know if you’ve ever covered this, but do you have a specific goal for the car? Certain ET or trap speed?
 
Let's try this. I did a video capture of the log from the 6.8 pass. Sorry, no vroom, vroom sound effects. I was pleasantly surprised to see it went straight to about 10psi in about 1 second. AFR was a little rich also but that was expected. I left it on the richer side since I've never fine tuned it this high into boost before.
 
turbovan said:
It’s been really great to see your build progress with test results from the track. You’ve conducted a massive amount of R&D for our community and I’m extremely grateful. I haven’t gathered the balls to run mine at the track yet for fear of breaking something, but I’m dying to see what it will do. Someday…

I don’t know if you’ve ever covered this, but do you have a specific goal for the car? Certain ET or trap speed?
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Take it to the track! Safest place to test. Just don’t try to be a hero or break any records and take it slow at first. Prepare to be disappointed, or maybe not. Take lots of notes, log everything, review, make changes, test….rinse, repeat. I’m an engineer by day so that routine is pretty much in my DNA.

As far as goals for this build, when I set out I just kind of guesstimated that this combo should go 6.50-6.70 and be somewhat streetable/reliable. I think that’s about an honest 600hp at the flywheel at 3200lbs. I’m close.
 
turbovan said:
Nice! I WANT to play with mine more. I “watered down” the hy-guard in my transmission with atf+4 to gain about 200 stall rpm bringing me to ~3200. I’ve gone into the negative degrees, but still hit the hard limiter which I don’t believe is desirable? I’ve not messed with hysteresis enough. It just builds so much under hood heat so quickly, and the limiter feels borderline violent. It’s fun, and I’d love to mess with it for hours, but it just doesn’t “feel” healthy for the setup. Plus I can’t put that power down from a dig(street) anyways; 2nd gear rolling 2step hits are a blast though!

Any idea if testing the 2 step is as rough on the build as it seems? Or does it just feel that way?
Click to expand...
You definitely want to get it on the chip. Thats how you really start to build boost. I typically don’t pull any timing until I’m on the 2step, if the converter is tight and the motor doesn’t have any nuts it’s sometimes hard to get it to the chip initially with a bunch of timing yanked out of it whereas once you’re already there it’s harder to get it to “fall off” the 2step unless you get really aggressive with retarding it. You can also throw fuel at it too while on the 2step go help with spool. The goal is to get exhaust energy at the turbine. So firing late or getting fuel to ignite in the exhaust is how you accomplish it.
 
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