Story Time - Plus DIY TD04 Upgrade

[Shailer Andrew]

As I mentioned, there were a few areas where clearance was an issue due to the turbo sitting further forward.

- Compressor housing to radiator support
- Downpipe to hood lock/ radiator support
- Intake to radiator support
- Compressor outlet/intercooler pipe to radiator fan shroud

The first two were remedied by removing the hood lock and cutting out the back side of the radiator support. It is a two piece crossmember spot welded together, so the front section stays mostly intact. Without the hood lock there, and the outboard locations of the upper rad pins, very little load goes through this crossmember anyways. As for the intake clearance, there were two large bulges near the mount for the front crash sensor. These were pushing in on my fenderwell intake elbow. Rather than cut them and worry about creating edges, I heated them up and smashed them in. Not pretty, but it left me about 10-15mm of clearance in the end.



To address the last clearance item, I took to the ribbing structure on the back of the radiator fan shroud. I had already taken some material off with my 1752 in order to work with my DIY intercooler piping, but now I entirely cleared a path for the intercooler elbow to avoid being rubbed through.



Now for preventing the hood from flying open. i decided to go with Aerocatch hood pins (120-4000 model is $65). I had seen Eddie also use these with his TD05 swap, and despite not finding any picture, I was able to make a good assumption as to where he mounted them. The adjustable hood stoppers sit near the headlight mount on the radiator support. They are positioned nicely at the corners of the hood. Conveniently. the stoppers also left marks on the radiator support. This would be by starting point for drilling to mount the pins.

I then cut rough holes in the hood frame to allow the pins to reach the hood skin, where I then marked for my pilot holes.



The rest is standard template stuff explained in the Aerocatch kit. I decided to mount the latches rotated 90deg from what some would consider 'normal' or 'more common', but this was because of the curvature of the front of the hood. I know Eddie did not mount his this way, but I found that going across the hood allowed the latch to lay flat more naturally. Anyways, I was able to make the top edge of the latch parallel to the bottom of the hood vent to at least provide some visual flow. I brushed some touch-up paint onto all the raw edges and final assembled the following day.



Once my dad finished welding the downpipe for me, I ground out the inside to smooth any rough spots near welds and then we wrapped it. He was an awesome wire tie tool made by Clevite that we used to secure the wrap with stainless wire rather than the stainless steel ties or hose clamps. These things clamp extremely tight and provide a subtle touch. The final step last night was to get the downpipe installed and the midpipe connected. Tonight is final assembly and then she'll drive. (Don't worry about the wet exhaust manifold, it's just WD40. No leaks)

[Shailer Andrew]

Got her all buttoned up last week. Really it was just a matter of throwing the radiator, intercooler and bumper beam on. I had started the car briefly before without the downpipe (LOUD) but this was the first time it got up to temp and had coolant in it. A little smoke from WD40 and exhaust wrap, but other than that no leaks so I'm in good shape.



I took the car out for a test drive on my existing tune, and it's amazing how much better throttle response is when your compressor wheel isn't dragging on the housing. I let it rip and noticed a super raspy sound/only hitting 10-12psi on the boost gauge (wastegate blowing wide open). I was keeping a close eye on this and the AFR gauge because obviously the tune wasn't adjust for the turbo. I came back, cranked up the wastegate actuator preload and then saw 15psi. Again, cranking it to an unreasonable amount, saw about 18psi. The wastegate port on this exhaust housing is much more parallel to the exhaust flow, and also much larger. Compare this to the 90deg turn that exhaust air needs to make on the OEM housing, and much smaller diameter. With these differences, the new turbo is bound to flow more exhaust through the wastegate for a given duty cycle. I confirmed that the solenoid is working with 12v applied, and also confirmed that the turbo is working fine by disconnecting the line that goes the the actuator. This forces the wastegate to stay closed (all the boost) so I only stayed in it until I saw the boost build to a normal value, then lifted.

These things will be resolved through tuning, I just wanted to make sure all hardware is good to go so we aren't chasing our tails with the tune.

For the final piece of the puzzle, I picked up a set of 550cc injectors. I noticed on the datalogs from my drag strip runs that my injector duty cycle is climbing over 90-95%. These things are completely tapped out, and then I have a 375cc/min meth nozzle on top of that. My AFRs hovered in the low 11's but I wanted to run the injectors at a safer duty cycle. After getting input from John, he told me to make sure I get the long tip injectors. Most other options, ATP drop-in or EVO X injectors both have short nozzles. He said this can cause pooling and poor spray pattern in the intake manifold.



Here is a video with the wastegate actuator disconnected. Hopefully this link works. I was watching the boost gauge to know when to lift, but I think the turbo will be full tilt around 4000rpm. This was 3rd gear around 45-50mph for some context on the spool. I'll report back with video of how this thing runs when it's actually tuned.

https://vimeo.com/451937398

[Mr.felop]

damn buddy and I thought my car was so loud with the atp I got from you

[Shailer Andrew]

Well, I'm an idiot. Ignore all of my justifications for why I wasn't hitting boost levels. Despite checking the WGA solenoid plumbing against internet references, I still messed it up. I think I was losing it after some of the longer nights working on this thing.

So ignore the previous post, the car runs just fine and boosts properly on the existing tune I had (same wastegate settings etc.), but there is a catch. On the top end, using my old tune, I'm getting on-throttle compressor surge. Most people know compressor surge as the fluttering that occurs when someone runs without a BOV, or too small of a BOV and air pushes back through the compressor. On-throttle compressor surge is the same phenomenon of air pushing back out through the compressor, but now it happens under load. This can be much more damaging because the exhaust side is trying to spin the assembly one direction while the air pushing out is trying to slow it down in the opposite direction. Off-throttle surge is less concerning because the rotating assembly can slow down while the air pushes out. The scenario I experience can be identified by the surge line on a compressor map. Basically, the turbo is moving more air than the engine can ingest, so it has nowhere to go except back out the turbo.



This makes sense, because the tune is setup to squeeze power out of the smaller 1752 on the top end where efficiency is degrading. With the new turbo, the boost will likely need to be tapered down more on the top end (the typical scenario of a larger turbo making the same power on lower boost).

Regardless of this, I was in the process of getting a tune sorted out, but earlier in the summer my friend set up a private track day at New York Safety Track. I have been there a few times, and this time I had friends trekking with me from OH, so I decided I would run the car as is and short shift before the surge happens (somewhere around 5500 or 6000rpm depending on the load scenario. My dad also reminded me of the beauty of this turbo, 50 bucks and i can slap new bearings in it if the surging did in fact do any damage.

We ended up getting a bit of rain in the morning, and my first experience on R888R in the wet was a blast. The afternoon dried up and we got to put the hammer down. Everyone's cars did great and I had a blast tangoing with my friends. Having to shift early did suck, because the boost threshold is so high, so I had a tiny little powerband to work with. As I got heated with friends, I rung it out a little further and said it is what it is, I'm gunna have fun.





At the end of the day, I heard a horrible exhaust leak coming from the front of the car. After some inspection, I was able to see that the thin Volvo turbo gasket (on the top side of the adapter plate) was partially missing. I suspected that this was due to the fact that I didn't torque the allen bolts (between the adapter plate and turbo) because I was nervous that the head would strip out. These bolts are needed because of the blind holes into the turbo. The turbo was able to gap from the adapter plate and blow the gasket out in a combination of fluttering + heat. As I later realized, these were grade 10.9 and could handle plenty of torque.



Unfortunately, this meant tearing the entire car down again, i prefer to pull the entire manifold to be able to get a torque wrench on all of the turbo to manifold fasteners. Having done it enough, and the fact that everything has already been apart, it took 2 hours from pulling on the ramps to having the nose of the car off and the turbo/manifold disassembled, not bad. The turbo feels and looks fine, so the track day wasn't catastrophic even with the surging. Here was the gasket failure.



All in all, it was a good first run and I'm excited to actually get the thing tuned. Hopefully everything stays tight now that it's actually torqued, but I can access the fasteners between the adapter plate and turbo while it's on the car, so I plan to check those periodically until it proves itself. Oh, and if anyone has hood pins that are mounted to the radiator support, and you want to keep them perfectly aligned to the hood, here is a trick. I just drilled small 1/8 inch holes that way I could stick drill bits/pins through the mating parts and get everything aligned because the bolt holes are oversize.



Next time I post, it'll be to report on my tune.

[Shailer Andrew]

Been waiting for a little while now, but I got the handheld from Multiair Tuning & Development and they sent me a base map last week. It's nice to finally be able to drive the car without compressor surge and pull it till limiter. The tune feels extremely smooth, and I'm really impressed with their part throttle boost control. Right now it's only running 20psi, but I should have a revision coming within the next day or so. If things go well, this Friday is the season ender at the local strip. If the tune revision looks good then I'll definitely stop by.



I wasn't aware of long tip 390cc injectors, and that's why I got the 550cc. MTD informed me that long tip 390cc injectors are available, and this is typically what they use for 93 applications. They've been kind enough to work with me on these. I was told idle tuning would be a little more difficult particularly on our Magneti Marelli ECUs, but in general this is common with larger injectors. For now they are ironing things out with 93 only, and then we will add the meth and pull fuel.

I also attached an image of a log on Multiecuscan. You can see boost reaches full tilt right around 4000rpm. It's been incrementally increasing over the years with my different setups, so it doesn't feel obnoxious to me. I'm sure if I drove a stock car it would be much more apparent. Next year I'll also do some roll racing with my buddy's stock car just to see how the powerbands compare. Obviously a dyno will tell more about the true torque curve rather than just the boost curve below, but that probably won't happen till next year. I'm basically going to get the tune dialed in and then park the car for the winter.

[Shailer Andrew]

Well, unfortunately the weather didn't permit for the drag strip being open and now the season has come to an end.

Still iterating on the tune, but similar to my previous statement, I was still getting slight compressor surge at WOT above 5500rpm or so. I picked up an anti-surge compressor housing, only about $130 from the same chinese maker of my current housing. This groove sits roughly in the middle of the compressor wheel, and the holes you see around the circumference are drilled through into it. It's usually referred to as a map groove because it changes the compressor map (moving the surge line as I mentioned in a previous post). This is essentially like an intentional boost leak, it also allows air to escape the system under WOT more safely, rather than hammering back through the wheel.

I found a pretty interesting post about how the width of the groove will change the map. These guys had a special housing where they could thread the entire inlet in or out and change the width of the groove for back to back dyno runs.

https://borowskirace.com/blogs/news/...p-groove-width

My housing measures about 3mm for reference.



Unfortunately, but not surprisingly, the holes for the WGA bracket are drilled differently between the two housings, so I just had to slot my bracket and drill and extra hole. It was relatively easy to swap this out with the turbo installed, I just had to remove a snap ring and the housing comes right off after disconnecting the intercooler pipe, WGA, and boost reference line.



With this change, comparing each housing on the same tune, the anti-surge has a slower boost response, and overall boost pressure dropped about 2psi and no surge so far. This will be accomodated in future revisions, but it makes sense that this would happen. It makes some wild hissing sounds at low vacuum/low boost. Most people will be familiar with the typical diverter flutter the Fiats have at low boost levels. Now, rather than that sound happening at the blow-off valve, it actually flutters out of the turbo, because that is the path of less resistance.

On a side note, my AEM Bosch wideband sensor went dead the other day. I was looking for a replacement that I didn't have to order online. The Bosch part number that AEM uses is 17025, which you can order online for a decent price, but to get locally was over $100. I found the Bosch 17212 sensor at Advance Auto, which has the same connecter, but a different sensor tip and shorter lead, otherwise works great. I got this for $52 after coupons, just in case anyone is ever in a pinch.



Also, does anyone else log with MultiECUScan or use Dragy? I'm contemplating picking up a Dragy as a fun tool, but I think it would also be interesting to compare logs of different setups/tunes.

[doverosx]

I definitely use MES ;-).

[Eunospeed]

Just discovering this thread.... love how the roll over (lemons to lemonade) turned the car into a track weapon. I'm debating going down the track-toy path with my '16 Abarth.

I'd love to get up to Columbus next year and check out the car first-hand. Only 200 miles from Lexington, KY.

[Shailer Andrew]

I definitely use MES ;-).

Of course, we will have to discuss once my tune is finished up. Should only be a few more iterations.

Just discovering this thread.... love how the roll over (lemons to lemonade) turned the car into a track weapon. I'm debating going down the track-toy path with my '16 Abarth.

I'd love to get up to Columbus next year and check out the car first-hand. Only 200 miles from Lexington, KY.

It was unfortunate but in general not something I complain about! That would be awesome to meet up. If you want to meet at an autocross or something too, it would be a fun time. I'd be willing to head south and check out something new.

[Shailer Andrew]

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)