Patrick's Twin Turbo 350 Build Thread

A lot of work there!
Looks good

 

How do you plan to shield the master cylinder from the turbo/downpipe heat? Ceramic-fill blankets? Steel heat shields?

 

As mentioned at the end of that post, I am going to use a turbo blanket on the turbine, wrap the downpipes in header wrap, and build a steel or aluminum heat shield. A trifecto!

 

Sounds like you're going thru a lot of extra crap because you boxed the frame? Why?

 

I did it for handling benefits as I want to drive this car on a road course, though it was also a "while I'm in there" thing!

 

BTW....Nice looking welds!!

 

Hey all, some small updates! My official deadline to get the car on the road in naturally aspirated form is October. My girlfriend and I want to take a road trip down to LA to visit some friends and family and also go to the Last of Us haunted house at Universal Studios!

Here’s my long list of stuff I’m going to try and do before then

As you can see, I’ve made some small progress. It’s definitely overwhelming but I’m just taking it one thing at a time. I’m sure there’s 100 other things I’m forgetting too! The things in parentheses are "nice to haves" but not required to drive:

-Mount radiator *DONE*
-Fab fan shroud *DONE*
-Buy radiator hoses/fittings *DONE*
-Install radiator hoses
-Buy rear CAs/sway bar *DONE*
-Install rear CAs/sway bar
-Set pinion angle (extend uppers)
-Get U-joints replaced, shorten driveshaft if needed
-Install rear shocks
-Attach brake pedal rod
-Bend front brake lines to meet new MC location *DONE*
-Secure brake lines to frame *DONE*
-Measure for trans cooler soft lines/determine trans cooler mounting *DONE*
-Buy/install trans cooler lines *IN PROGRESS*
-(Build 2nd fuel line)
-Install heater lines
-(Touch up engine bay paint)
-Patch in new pass side exhaust *DONE*
-Reinstall engine wiring harness/ignition/battery and hold down
-Buy repop front bumper
-(Paint hood latch) *DONE*
-Install grille/headlight bezels/bumper
-Weld seat brackets/install seats
-(Fix floor rust)
-(Install new rearview mirror)
-(Install new window regulators)
-(Install new carpet)
-Re-clock steering wheel
-Install temp rubber fuel lines
-Install steering components
-Grease all bushings/torque all suspension fasteners
-(Install glass hood)
-(Redo tail light wiring)
-Install tail light lenses
-Install smaller rear tires or further clearance pass side wheel arch
-Install throttle cable
-Set TV cable
-Install power steering *IN PROGRESS*
-Fully install trans pan/fill trans with fluid
-Fill/bleed brakes
-Fill/bleed cooling system
-Fill/bleed power steering
-(Diff fluid change?)
-Prelube, fire engine, double check for leaks
-Check trans pressures
-Rough alignment
-Test drive, verify trans operation/brakes/NSS
-Check trans pan spacer for signs of heat damage
-Install gauges (use engine stand gauges if short on time)
-Verify no drive line vibrations
-Verify no overheating
-Pro alignment
-(Fab oil pan guard)
-(Buy/install Killduff Shifter)
-(Radio/Kick Panels w/speakers)


Radiator Mounts:

The radiator I’m using is an AFCO unit which has a 16AN inlet and 1 3/4” angled up outlet. I know it’s strange, but it was the cheapest double pass unit I could find at the time that wasn’t made overseas and has good tube sizes. Being double pass means that the inlet and outlet are now both on the passenger side, since the water has to flow back and forth. I know that I’ll be mounting an intercooler at some point, so I experimented with different placement. Ultimately I used the Summit Racing Fan Shroud Kit I bought to determine that spacing so I didn’t have to do any more cutting than necessary. It just so happens that this mounting location allows 6” of space for an intercooler up front, which should be plenty. I spent some time test fitting the radiator/shroud in various locations, trying to keep it square to the fan:





Hood clearance is tight!



I read that it’s optimal to keep the fan 1/2 to 2/3 inside the shroud, so I shot for half. This is what I came up with for lower mounts. I decided to make some small cuts in the lower core support to allow my mounts to sit flush and move the radiator back into the correct location:





The lower mounts use rubber isolators front and back that I found on McMaster. My system ties into the mounts that came pre drilled in the radiator. Here they are painted after fully welding:







I also for some reason decided that I need to practice my aluminum welding skills, so I decided to try and make the upper mounts out of 6061-T6:





Yup aluminum welding is still as hard as I remember! At least it’s good practice. Upper mounts use the same isolators.

Fan Shroud:

As mentioned, I was using one of Summit’s kits to build a nice custom fan shroud, needed since I’m changing mounting locations. I also think the stock plastic shrouds on most cars are kinda ugly. I was building the radiator mounts and shroud in tandem since the radiator location was determined by the shroud thickness. The kit comes with a welded tub and rolled strip of 3” wide sheet. Everything is ~1/16” thick. First I determined a good mounting location for the tub where it doesn’t interfere with the steering box or frame. I decided it made sense to use the same holes as the radiator mounts. It luckily is just tall enough to fit, though the bottom holes became slots as there were very close to the edge. I clamped the tub to the radiator and marked/drilled my mounting holes. I then measured to make sure that the fan was in the should halfway and the radiator wasn’t hitting anything on either side. Once the radiator mounts were built I bolted everything back together and used a sharpie zip tied/clamped to the fan to mark where the strip would be placed. My original idea was to make the bottom of the strip removable for easy removal of the radiator/shroud as a unit, but I realized after cutting the strips in half that I was able to easily slide both in with the fan still mounted



Oh well, once I had my fan marking I simply laid the strip out 1” larger in diameter and proceeded to tack weld into place. I ended up welding the 2 halves of the strip back together and then put fillet welds every 8” or so around the outside. My fan actually was slightly larger than the tub, sticking up over the top about 1/4” and under the bottom about 2”. I cut small plates out of more 1/16” aluminum to make fillers, and welded these in as well. I think the whole thing turned out pretty nice, I just wish my welds were prettier!





Upper filler panel:





Lower filler panel:





Mounted!





Lastly (and painfully) I cut out the hole for the fan. I used a combination of an air powered reciprocating saw (slow and annoying) and a cutoff wheel (fast and rough). Here’s what it looked like after I finished the cut:



Then I ground down the rough cut edge flush with the inside of the strip, and mounted it all back together! The whole thing probably took me two 5-hour days.



Misc:

Also decided to paint my hood latch and support, they looked ugly being mismatched with the rest of the engine bay:





Lastly, I am in the process of the GM Type II Power Steering conversion!

 

DAMN that’s a lot of work there, good job!!
Thank you for the updates too!

 

Cool fab work looks good how soon till the maiden voyage? That fan shroud won't break lol

 

The steering wheel should be aligned to the column shaft. The shaft and the wheel should each be marked for alignment by GM. If someone moved the wheel on the steering column shaft, you can bet that something farther down the steering system is screwed up. Likely candidates are the rag joint, and the tie rod end adjustment, although those are not the only possibilities.

The steering wheel should be right-side-up, and level when the steering gear is on it's "high point", exactly centered. Counting turns lock-to-lock and dividing by two MIGHT get you to the high-point...or maybe not. Best to verify at the steering gear itself.

I really hate seeing rubber hose on the pressure side of a fuel pump. Be careful. Consider using the usual double-wall seamless-steel tubing these vehicles were made with. Short sections of quality rubber hose only where needed to account for engine shake, and even then hopefully on the suction side rather than the pressure side. Sometimes hose on the pressure side is unavoidable (fuel pump in the tank, for example) and then you REALLY need quality hose. In that case, I use the Teflon (PTFE) liner hose covered in steel braid, rather than rubber hose.

I'd have said 1/2 in, 1/2 out, 1/3 in, 2/3 out preferred.

Those cuts to the core support will weaken it. Might want to weld-in some reinforcement.

I would have used some rubber material UNDER the rad, rather than supporting it from the side. I've seen those sort of mounts tear from repeated stress, then the radiator is bouncing off of the metal below.

You have 1/2" of clearance between the tips of the fan blades and the shroud ring? Looks like more clearance than that--2+ inches of diameter, ~1" to the fan tips. "Tighter is better"...until the engine lifts under torque, or the body twists and the fan blades hit the shroud. If you really do have 1/2" to the fan tips, be sure your motor mounts and body mounts are in good condition. Chassis flex is NOT your friend in this case.

If that works, great. If you have heating issues, consider cutting the shroud ring some, so that the fan is farther out/less-deep in the shroud. Automotive fans blow air "rearward", but they also throw a lot of air out to the side. When that sideways flow is restricted because the fan is too deep in the shroud, the fan becomes less efficient.

 

Hoping to fire it up and drive it around to test the trans sometime in September!

So I pretty much built it all from scratch, new steering box, rag joint, tie rods basically everything except the column. The steering wheel is from a T-Type. It's definitely possible I messed something up somewhere! I was going to try the lock to lock method of centering it. I think the wheel is only off by a spline or 2. I did notice that you could only mount the steering wheel on a specific range of splines and still have the horn wire hole line up correctly. The tie rods aren't even connected right now so that's out of the equation. I can feel where the steering box has a tight spot and the pitman arm is centered, so I'm assuming that's perfect middle?

Totally agree, the rubber fuel line is not my first choice. This is mainly for the long lines from the tank to pump (return and send). I could definitely build a new hardline for the pump to carb, would that be safest?

I'm building nicopp 1/2" hardlines but those are more for when it goes EFI, for now I was going to run rubber in the interim (for this road trip) since it'll all be thrown out soon, if I did PTFE it'd be a waste of fittings and hose! I am however using PTFE hose and AN fittings for the power steering pressure line and trans cooler lines.

I can definitely do some reinforcing to the belly, but I was hoping that since my top mounts are providing more support than that OEM "clamping" method, it would be ok? Dang I should have researched more, I thought fan 1/2 in was perfect Cutting the shroud is always an option I suppose. We'll see how it cools!

Clearance is 1" greater on each side than the diameter of the fan, so roughly a 20" circle for my 18" fan. Sorry my wording was confusing! It actually turned out to be a little tighter on top and looser on the bottom due to marking error, hopefully that's still ok. Looks pretty centered side to side.

 

The rad support is more than fine

 

Alright guys . . . . IT RUNS!!!

All I have right now is this short cell phone video, I'll get something better soon:



Since I'm supposed to be driving to LA in it in like 4 days, I'm scrambling around trying to do everything else to make it road worthy! I promise I'll post actual pictures and updates soon but it's been a mad dash for sure.

Yes I know there's an exhaust leak at one of the manifolds, and the wiring is all exposed right now!

 

Good job!
Keep ‘er going

 

It not only runs, but now it DRIVES!! Here are some pictures of last night when I for pulled out of the garage for the first time in 6 years, and a little video of me driving it to work this morning.















I actually felt a little high driving it around last night I think the fact that I was actually in this car driving it was so overwhelming that my brain couldn't handle it. It still hasn't really sunk in actually!

There is still a long list of things to do before we leave on Saturday, as I write this it's on the alignment rack. Mostly it's small stuff but I still have to do some more test driving. The biggest thing is I don't think my lockup is working, I'll have to troubleshoot the Bowler module to see what's up. The shifts feel pretty firm, I might play with the TV cable a little but the pressures did look good and it hasn't fried after 11 miles so I'm hoping everything is okay!

The good news (maybe) is that I haven't been able to get the coolant temp past 160 yet, though I haven't tried super hot heavy traffic either. But I think my custom shroud and big ass radiator are working well!

The car feels pretty damn stiff in front, it definitely needs better shocks with the 2" BMR drop springs all around. It also sits way low which I like but it puts the trans pan and oil pan very close to the asphalt so I have to be really careful on bumps etc. I actually had to make a janky wood ramp to even get it out of my garage and onto the street! I think the front drop is closer to 2.5" since I also have half inch taller lower ball joints. Might end up welding some sort of skid plate up to protect everything under there. At least I don't have to worry about long tube headers!

All in all I'm just so happy that the damn thing is on the road finally, and I'd like to thank all of you for your support during this whole process. This build is far from over, this is only stage 1 (NA and drivable). Stage 2 is the EFI conversion, and stage 3 is the twin turbos finally!

 

Nice work.

 

That's awesome. What linkage are you using for 2004r?

 

Reminds me of my HO Racing suspension set up, heavy springs, big sway bars, boxed lower control arms in rear with big sway bar, Camaro front spindles with disc brakes, car is lowered and can take turns like a Vette.!

 

I think that 350 will make enough torque and horsepower that you will forget all about doing a 455 in the future. Not having to worry about puking the crank out the bottom is definitely a plus.

 

I'm using a cheap Lokar style adjustable column shift linkage knock-off that I found on Amazon for about $30. I've used the real thing and honestly I can't really tell the difference, but it did make the spacing between gears really short even maxed out to the longest swing if that makes sense. I had to cut and bend the rod to get it clear of the firewall (same as the Lokar).

I'm planning on doing a floor shift conversion very soon so I didn't mind using something cheap for now!

Sounds like a champ! The problem I'm having right now is being too low in front . . . I keep scraping my deep trans pan, and a tiny bit of the SRE oil pan if I hit a bump. Luckily no big damage so far, but I overnight ordered a set of spring spacers that should raise the front up by 1.125". Going to put them in Friday and leave for LA Saturday! It's sad because I like how it looks slammed but it's just not practical or fun to drive like a grandma and scrape up my nice parts.

So far though I'm loving driving it, it sounds great. I finally floored it last night for the first time from a roll (after checking my timing, total is 35 degrees). Maybe it's just because I've been driving sub 100hp Toyotas for so long, but that 350 screamed and threw me back in the seat, put a huge smile on my face!

I tried flooring it from a stop this morning on the way to work, and the carb backfired and the engine died! It started right up again, but it looks like I have some tuning to do. I'm guessing I need a more aggressive accelerator pump shot? Any advice on where to start?