Triple Blowthrough Turbo

[Dat73z]

Last month blew by but good progress has been made on the chassis. This next few weeks I'll need to finish stripping a few things off the chassis and get it loaded onto a body cart for transport in May. 

 

Due to the uncertain tariff situation I procured a few parts I was initially planning to order after the car goes out. I decided to eat the costs now as prices could potentially increase 25%-200%+ on the US consumer tax side and who knows how sticky that will be. 

 

For the turbo build refresh I wanted to beef up the chassis and rear end. A few weeks ago I dropped off the Q45 diff for a full rebuild with R34 GT-R 3.54 gears and a OSG Super Lock LSD. My rear end was also already structurally reinforced and plated in, but I decided to take that a step further with a Escort JP single piece rear end. I also received a PTZ rear finned cover, which I will need to perform some machine work to fit. 

 

For additional chassis reinforcement, the OE type competition rollbar should arrive soon. It's more of a historic/obscure part but I'll post some mockup pictures for anyone who's interested. 

[Zetsaz]

15 hours ago, Dat73z said:

Last month blew by but good progress has been made on the chassis. This next few weeks I'll need to finish stripping a few things off the chassis and get it loaded onto a body cart for transport in May. 

 

Due to the uncertain tariff situation I procured a few parts I was initially planning to order after the car goes out. I decided to eat the costs now as prices could potentially increase 25%-200%+ on the US consumer tax side and who knows how sticky that will be. 

 

For the turbo build refresh I wanted to beef up the chassis and rear end. A few weeks ago I dropped off the Q45 diff for a full rebuild with R34 GT-R 3.54 gears and a OSG Super Lock LSD. My rear end was also already structurally reinforced and plated in, but I decided to take that a step further with a Escort JP single piece rear end. I also received a PTZ rear finned cover, which I will need to perform some machine work to fit. 

 

For additional chassis reinforcement, the OE type competition rollbar should arrive soon. It's more of a historic/obscure part but I'll post some mockup pictures for anyone who's interested. 

 

 

Daaaaaaaaaang

 

You had literally the same idea I did. At a minimum I think I'll be ordering an OS Giken LSD to avoid future tariffs. That Escort piece is super nice. Was tempted to get the escort finned R200 cover, but I know realistically I have no use for it. Will be negligible benefit at best compared to my oem finned cover. Better off saving that money for the KW suspension haha.

 

Looking into more stuff that I might need in the future and trying to get an import order done within the next week.

[Dat73z]

@Zetsaz a lot of my friends have been doing the same 😅...not a bad move imo if you're planning to use the parts. My OSG LSD actually came in a month or so ago before this whole mess but as we've seen things can change by the hour lol. 

 

One thing to look out for is some importers have already been upcharging 25%+ for "tariffs" even though they aren't fully in place yet. I was asking around this past few weeks and got similar stories from a lot of 3rd party importers so maybe they were anticipating and charging the 25%+ upfront to be safe, but who knows if they would've pocketed the fees or refunded those extra costs if the tax bill didn'tcome in. I ended up ordering parts direct from JP companies like Escort and they did not charge me the thousands of extra in "tariff" fees, they just let me know if it's stopped in customs I would need to pay the taxes to get it released which has always been my experience prior. 

[Dat73z]

Continuing on chassis reinforcements, the Nissan comp OE type rollbar will be delivered later today. The OE type rollbar bolts to the existing m10 captive nuts above the rear tubs and also to the trunk floor straddling the reinforced u-channel between the rear shock towers and rear suspension/driveline mounting points. For the floors I've started fabricating some 6"x6" 1/8" steel doubler plates which I will weld some captive nuts as they do in the JDM then stitch them in with the tig. 

 

In preparation for this, I bolted in the Escort 1 piece rear end which will stay in place for fabrication. Given the reinforced structure of the rear suspension points, I don't think things will move around but just for peace of mind that everything bolts up properly before and after welding. I've learned my lessons over the years from welding warpage and fixing my mistakes with blocks of wood and BFHs 😂

 

I also decided to mock up the PTZ cover one last time to verify dimensions before machining and I'm not sure how I got this so wrong but everything fits. I was under the impression that the Escort geometry was the same as OEM so maybe the T3 geometry is different. Not a big deal either way, as the front diff mount needs a bit of refabrication for the exhaust and shortening the AL driveshaft is straightforward. I also have some spare Q45 diffs I could blow apart and check for fit, but I'm running out of time and need to do some other welding and misc. chassis work before it goes on a bodycart for transport next week. 

[Dat73z]

Some quick photos of the Nissan comp OE type roll bar test fit to determine the final position of the trunk floor plates. The roll bar is an absolute work of art made by Romas at DCW Classic.

I've definitely learned a lot about the racing history behind the s30 and am grateful to have made many new friends all over the world this past couple of months, exchanging notes with experts in the community such as Romas, Alan T, Kats, Chris, Florian, and many many others. This build definitely would not have been possible without the support of the community. 

I started flattening the trunk floor for welding yesterday but I think I'm going to take a break for a day to fully prepare the welding areas and work through the interior overall which is covered in old sticky adhesive/tar remnants. 

[calZ]

The rollbar looks great. Would you mind taking a picture from below to show how close it is to the roof structure? 

[Dat73z]

@calZ here's some pics and rough measurements. I believe the roll bar is designed to fit around most the interior of the car, with some areas such as the interior quarter panel pieces requiring trimming around the bracketry. Also, to my understanding there were only a few of these roll bars produced and I'm not sure if or when more will be made. 

 

A quick mid-weekend update: I finished fabricating the rear deck plates by welding in captive nuts, weld through primer on all surfaces, then tacked the rear plates in. With the main hoop torqued in the plates are in perfect alignment for the fasteners to thread by finger.

 

To be honest it was a huge pita timesink to straighten the floors where possible for tig prep, but I'm glad that's all done. A friend mentioned that in-period the plates would've probably been mig welded in, perhaps poorly with mig wire sticking out so sanitary tig dimes are probably going to look out of place 😂. 

 

Now I just need a couple of hours to take my time and stitch weld the plates then finish with some self etching primer. 

Edited yesterday at 01:10 AM by Dat73z

[calZ]

Thanks! Looks like they did a really good job of getting it tucked in there. I'm tall, so I've just been assuming I'll have to go custom to get something that isn't within reach of my head. 

[Dat73z]

Yeah the geometry of the s30 is just difficult. I am also tall and every s30 with an off the shelf roll bar or cage (autopower 4 and 6 points come to mind) has put the main hoop at my head or had some combination of factors making the seating position awkward. I would definitely go custom. 

 

Last night I was able to mostly stitch weld everything in. Not my best work but I was getting good penetration so I'm confident it's strong. Every weld was done crazily out of position with the foot pedal on the floorboards or contorted sideways with with a leg out the door 😂. I'm really hoping I can wrap this today as I need to move back to welding in the engine bay. 

[A to Z]

love the custom work.  I installed an AutoPower race 4 point rollbar, and later had to cut out the straight across bar down low.  I just HAD to recline the seat!!  On the diagonal bar I put a piece of rollbar foam on to rest my head.  I made it work.

[Dat73z]

I'm not a fan of the bolt-in s30 Autopower roll bar or cages overall but they have their place and purpose. 

 

Today got busy but I managed to squeeze an hour in check the final fit of the roll bar and prime the floor in, which gives an idea of what things may look like painted. I'm planning to run full interior and custom carpet so it'll all be hidden anyways. The bodyshop also let me know the rotisserie is ready for my chassis.

 

There are probably a dozen other things I could do on this but I'll leave it to the shop as they're going to paint the entire underside, inside and outside.