Story Time - Plus DIY TD04 Upgrade

[doverosx]

Had some fun with the Dragy last night. Found another person who did 30-55mph (2nd gear) and 50-75mph (3rd gear) just as a way to compare without considering launching or gear shifts. Also, I did a 40-110mph. I plan to do a 62-124mph (100-200km/h) mostly because I'll be able to hit that speed in 4th with a raised limiter. Based on calculations with my current 15in wheel/tire combo, I would need 5th for a 60-130mph.

Unfortunately it seems like very few in the Fiat community have Dragy or any care to compare data, too scared to face the realities. Others prefer to live in a world where their car 'makes 300' and they can race with their keyboard.

Raised limiter and meth soon, nearing the end of tune revisions.

30-55mph (2nd Gear)



50-75mph (3rd Gear)



40-110mph (2,3,4)

Lmao, that’s for sure. They’ve been told to run away from dynos too!

Looks like I’ll be picking up a draggy.

[BigDaddySRT]

Where's your 8 point roll cage?

[Shailer Andrew]

The other day I also decided to change my meth controller from Snow Performance to AEM. The Snow Performance Stage 2 does allow for ramp-in of spray, but the upper boost limit for max pump output was only 20psi. Additionally, the controller was mounted in the engine bay and required a small screwdriver to adjust.




On the other hand, the AEM 30-3304 controller is a nicely packaged unit that has knobs, and most importantly the upper boost limit is 35psi. This will allow me to fine tune my meth spray (AFR) based on environmental factors if needed, without changing the nozzle. As a random example... lets say during the summer I set my nozzle size and upper boost limit so the pump is at full speed when I'm at max boost (20psi), yielding desirable AFRs. As the weather starts to cool down, maybe I notice the AFRs going rich. I can turn the upper boost limit knob to something higher than my max boost (let's say 25psi). This means that the pump will never reach full speed when I'm at 20psi max boost, and it will reduce the amount of meth spraying. This graph helps to explain.



Even outside of weather changes, this is useful for getting the AFRs exactly right. If the tuner pulls out X amount of fuel, I can start on the conservative side with a lot of meth, then dial it back with the adjustable upper boost limit (reducing the max pump speed). If I find I'm making significant adjustment, then I will downsize the nozzle and start over. I believe there is some argument about atomization of the meth at lower pump speed. I haven't done any testing to observe this on my own, but I don't plan to be running it overly slow. Similarly, adjustment can be made with pump pressure. My Snow pump says not to adjust the pressure, but I think that's just to cover them from replacing pumps due to early failure from operating at higher pressure.

The AEM controller also has some nice built-in features for pump failure, test spray mode, low-fluid warning, and boost cut if meth runs low. I won't be using all of these, but the ones I am are nice to have. I already have a button that controls a relay to manually spray meth, but I had to change it to a grounding relay to jive with the AEM controller. Unlike the Snow controller which only has a 12V wire to the pump, the AEM connects 12V and ground to the controller (that's how it can detect open/short in the pump). With the AEM the pump is always receiving voltage, AEM claims it helps response, so you will hear it buzzing even when not spraying. The controller varies the ground to make the pump spray.

[Shailer Andrew]

A few iterations later, car is running great. I got a chance to run a 1/4 mile on Dragy. It was about 30deg out on plain streets, so RE71R were rendered just about useless, and the launch sucked. This was knocking on the door of my previous fastest pass (timeslip posted previously), despite the slower 60ft time. Trap speed was also the highest it's been. This iteration had a 6800rpm limiter. This 13.9 was way easier to achieve, and the car runs flawlessly without misfire or hiccup.



I just got what will likely be the final iteration, with 7200rpm limiter and launch control added. Once I send a log off and get the OK, I'll be taking it to the dyno. I have all next week off from work, so assuming dyno availability, it will be very soon. I plan to take it to a dyno where a 500T dyno'd stock, EC P0,1&2, along with a 1446+ Abarth and EC P3. Results have been published for all of those runs. I figure this will give me a reference point since I've never had this car on a dyno in stock or other form. I plan to run two tunes, one is gas only & 6500rpm limiter and the other is +meth injection & 7200rpm.

[doverosx]

Awesome!

[Shailer Andrew]

Well, unfortunately didn't make it to the dyno. I was taking a log for the tuner last weekend and after pulling to limiter, I got a P0016 code. This code indicates some timing misalignment between cam/crank. My initial panic was that timing jumped somehow. First I did a compression test, everything came back spot on. Then I checked out the sensors, no clear signs of failure. I was finally able to check the timing with the alignment tools this weekend, yet again, everything looked perfect.

While checking the timing though, I noticed that that small pin on the crank timing pulley was sheared off. This is used to align both the timing tool and the crank damper pulley (which also has the crank timing teeth for the sensor to read). I wasn't sure how this happened, because last time it was apart it was just fine. Upon further inspection, I could see oblong wear under the washers of the 3 crank damper bolts. It appears that the bolts came slightly loose, enough for the pulley to rotate relative to the crank timing belt pulley due to the oversize holes. This not only sheared off the small alignment pin, but it also caused the car to think the timing was off.

I was able to put the pulley back into its proper position, visually aligning the hole with the sheared off nub. The car fired up and ran perfectly without codes.

I need to get creative for a better solution, because it keeps slipping. The pulley/washer surfaces are slightly polished now due to the previous vibrations so even when torque to spec, plus some, it slips when engine speed changes quickly.

[Eunospeed]

Very cool to see your progress! I live in Lexington, KY and would like to get up to Columbus this spring/summer and check out your build.

[doverosx]

Loctite time?

[Shailer Andrew]

Loctite time?

Loctite was unsuccessful ----- see below

In regards to my loose crank pulley, I first tried to loctite them and up the torque slightly. Again, they came loose after a very short drive (odd). Then, wondering if the alignment pin was critical, I brazed the holes on the crank pulley so they weren't oversized anymore. This successfully prevented the pulley from rotating relative to the crank even if the bolts were loose. This addressed the P0016 timing correlation code, but now I had a P0300 code, which was occurring when the bolts slightly loosened and the pulley vibrated. The crank position sensor could not accurately read the gear.



My final solution (overkill but frustrated at this point) was to use studs and locking fasteners for the crank pulley. This was successful and all of the codes went away.



Driving around a bit more, the car was running weird. It wasn't smooth, it was down on power, and it would stutter (but not misfire) under heavy load. I swapped out spare plugs/coils, checked vacuum plumbing, no luck. Finally I tried changing the tune for a previous revision. I was doing the over-rev sequence when I heard a loud metal rapping noise. It didn't sound deep enough to be a rod though.

At this point, I'm thinking wrist pin or piston skirt. I had been hearing a slight knock recently on after the starter disengaged on start-up, but thought it was somehow related to the timing being off. I mentally prepare myself for some level of engine overhaul.

After pulling the oil pan to assess things, my friend and I find the flywheel loose. Good news, engine looks fine and I now know the vibration source that's been causing crank pulley trouble. Considering we're in the middle of winter, I'm at 93,000 miles, and the car's life won't get any easier, I'm going to refresh it and throw pistons/rods in.




Here you can see the bolts have backed out. One of them was broken. Who knows how long this has been brewing, but I think it was the perfect storm including the raised hard cut limiter on the new tune. The aluminum flywheel has been installed for 40k miles, loctited, new bolts torqued properly. I've read plenty of things about loose aluminum flywheels, and also observed that ours don't have a steel torque plate at the bolting points. I'm going to switch back to a steel single mass flywheel because the center hub on this one is destroyed anyways. On a positive note, the FX350D clutch appears to work beautifully.



In hindsight, this final log I took before everything vibrated loose makes much more sense. You can see the increasing amount of spark reduction moving from Cyl1 to Cyl4. I would be willing to bet that this issue, along with my current performance issues, are related to the excessive vibration and false knock detection.

[Shailer Andrew]

New pistons and rods finally showed up the other day. Still need to order the the flywheel and clean up the aluminum that transferred to the crank from the loose flywheel. Unfortunately the 'grade' stamping on the block was pretty corroded, so I can't use that to determine what tolerance range my block falls in. The service manual has a complex table where you use the tolerance grade of both crank and cam to determine what combination of bearings to use. I'll just have to measure them, along with the crank after polishing.



Here is the table and the crank stampings for those who haven't seen the manual.