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Unzipped R34 Time Attack Build


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Hey guys,

 

As I mentioned in my thread in the Newbie Intro section, I'm back on the forum with a new account and username. Used to spend a lot of time on here years ago as Hanaldo, so some of you may remember me and my car. The old build thread is here:

 


That thread essentially covers everything I did to the car while it was my daily for 12 years. In September last year I got yellow stickered, and that was the end of that! I want to write this build thread to cover it's new life as a motorsport development car for my business (I will try to do that without breaking any forum rules). It is unfortunately going to be a slow build I think, I don't have a lot of time to work on the car these days, nor a significant budget for it. But hopefully once the Covid restrictions are lifted and we can get back out on the track, I can start to post some results and do some development. 

 

Power-wise, the last time it was on a dyno the car made 419rwhp @22psi on E85. There was plenty more in it, but it was suffering badly from ignition break-down at higher boost levels, and was just about on the limit that the clutch could handle. I bought an R35 GTR coil kit from Platinum Racing Products to take care of the ignition, and while upgrading the clutch to an NPC cushion button I also discovered that every single nut on the exhaust manifold was hand-tight and the gasket was blown - had probably been that way for months if not years. So we replaced that, along with the studs and nuts. While that was all underway, I decided I'd had enough of the old Link G4 plug-in, and decided to go all out with a G4+ Thunder and an MXS Strada dash. Unfortunately since wiring in the Thunder, we haven't had an opportunity to get the car back on the dyno for a tune, so that is about where things stand currently, but I am hoping to be up around the 480rwhp mark if not maybe sneak into the 500's. We will see, it is a factory bottom-end at the end of the day so I don't want to push it too far, and I'll be happy with where it ends up for a bit. I don't plan to build the motor anytime soon unless it breaks with a bit of track use, but it's always nice to know what it can do.

 

Ultimately the car will be aimed at Time Attack, built to compete in Tuner Class in WA Time Attack (the same regulations as Clubsprint in WTAC). I decided to build it for this category, as I am actually already sponsoring a car being built for Racer (Open) Class and investing heavily in that, so I wanted to do something different with my car and not be in direct competition with something I certainly can't compete with! Tuner Class also appeals to me for the challenge of developing the aero to perform in what is really a non-aero class. It is quite 'easy' to develop aero components for cars competing in Open Class as the regulations allow so much more, but in Clubsprint the regulations on aero are quite restrictive and will require a bit of ingenuity to get the performance out of it. I will be doing the CAD and CFD in-house, but my intention is to use the Thunder to get creative with data logging, so hopefully I can back up any lap-time progress/regress with data to show what is working and what isn't. CFD is nice, but real-world data is king!

 

That's about it for now, I will upload a few pictures soon and start taking more photos of anything that goes into the car so hopefully I'm not just posting walls of text! 

 

 

Edited by Unzipped Composites
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  • 2 weeks later...

Little bit of progress over the weekend, the interior has now been stripped out, just need to find the time to take care of the sound deadening (shudder) and gut the unnecessary stuff from the dash/doors/etc.

 

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Don't let anyone tell you otherwise, race cars pay for themselves

 

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All of the aircon gear has also been deleted, which was initially a bit hard to stomach for me... 

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ABS is also gone

 

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Still need to get rid of the heater box from under the dash, but will wait to drain the coolant first. It's amazing how much room just the aircon and ABS takes up in the engine bay, it's already significantly neater in there. 

I also decided I wasn't going to mess around with the OEM wiring harness anymore, and it's time for a full motorsport spec harness for the car. OEM engine harness is out

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Absolute reliability is my goal, as I've seen enough motorsport to know that electrical issues can be one of the most expensive parts of having a race car. Making my own harness has been a long-term dream of mine, so I'm looking forward to the challenge. I also need the wiring to be capable of evolving with the setup as I develop the car; because I plan on using it to develop performance aero products I want to be able to log as much data as I can in relation to those products. I am already developing some laser ride height sensors in order to log downforce, and in the future I would like to be able to run additional sensors for things like pre-radiator temps for oil/water/air etc in order to work out how well my ducting is performing. 

 

While I'm at it, I've decided to convert to DBW throttle as well, to save having to modify that part of the harness later.

 

All of this means that I am running out of AVI's on the ECU quite quickly. If I wired everything direct to the ECU, I would already have used all 16 AVI's with just the current sensors, 4 laser ride height sensors, and the DBW. The MXS Strada dash has 8 AVI inputs that I can make use of, but unfortunately doesn't have logging capabilities, and it is a bit hard to stomach the $1700 for the logging kit from AIM at the moment. So as an interim, I have setup the ECU and the dash on the bench, and am trying to workout how I can wire the non-critical sensors like ride height into the dash, and then stream that data to the Thunder via CAN in order to log it.

 

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Seems like such a simple idea, both units are able to transmit and receive CAN data, and the CAN channel is a loggable channel in the ECU. In practice, it's quite a lot of dicking around. AIM haven't made this dash very user friendly, so it isn't quite as straight forward as "receive this, transmit that". I may end up having to write a custom CAN protocol in order to get it to work the way I want, but the initial results seem to indicate that it can be done. This will free up a few AVI's on the ECU for future expansion.

 

Next up, I've decided to pull the motor out. It's been 8 years since the motor was last out, and I'm looking forward to sorting out the things I did wrong back then, as well as cleaning up the engine bay again, probably weld up some unnecessary holes in the firewall, and making it a lot easier to route the new harness when it's done.

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So you'r doing all new electronics in your car?  I'm doing same with my car. ? I'm personaly using PDM-box for all lights etc (I get rid of fuses and relays) and stand alone ECU. Maybe fuel tech, becouse there is ECU, dash display and data logger at the same. Those PDM (CAN stuff) are so easy to do wiring and programm and prices are low enough for normanl builder to buy things at these days. So I personally don't see any reason to do wiring with old relays and fuses anymore. 

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Yeh full rewire.

 

I'm not going to PDM though, just going to simplify and reorganise the fuses and relays. PDM's are great, but just not quite a priority yet. One day when I've had enough of fuses and relays, I'll redo it with a PDM. Gotta leave myself something to do in the future :P

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I rewired by 32 and put a smartwire PDM in (only fuses remaining are main ones near the battery under bonnet and only relays are the Ignition and ECCS ones), made it massively easier. You would not believe how many fuses and relays there are in these cars.

BTW thanks for the thread and I;m enjoying the fibreglass chat elsewhere that I don't understand a word of :)

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Yeh most of the cars I work with are PDM, they're very good. I just can't quite stretch the budget there yet, this is already turning into one of those 'oh shit I got a bit excited' parts of the cars life ?

 

And hopefully I'll have a bit more composites chat coming soon! As much as I enjoy talking turbos and 'Milspec' wiring - composites are my field and what will set this build apart! 

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  • 4 weeks later...

Spent a bit more time going backwards over the weekend:

 

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Couple hours later, engine was stripped down and the bare block, head and crank are flying around the back of the Territory.

 

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Turned out to be not a terrible idea to pull the running motor apart - bit of scoring on the mains and big ends showed she didn't have a lot of time left in her. Didn't have too much of a look at the pistons, they looked ok but no doubt have some cracked ring lands. Bores aren't bad, not as good as the last time I saw them when the head came off 8 years ago. But, everything came apart quite easily, nothing major going on so makes life easy from here.

 

To take my mind off questioning my life choices, the Alpha Omega Racing adapters I ordered awhile back rocked up last week, so I gave the old Evo 9 Brembo's I've had sitting on the shelf for awhile a thorough refurbishing. Disassembled the calipers and spent the time taking off the 4 or 5 old paint jobs with paint stripper rather than sandblasting, etch primed, then mixed up a custom paint colour using pearlescent powders:

 

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Wasn't what I had in mind when I started, but I don't hate how they've turned out. The photo's make them look a bit brown, but they are actually a metallic dark purple/maroon sort of colour. Wanted something different but not too wild, so I think they turned out alright. Just need to put the Brembo rebuild kit through the calipers, get the hardware nickle plated, and then reassemble and I can throw them on the car.

 

To go along with those, I also got a BM57 master cylinder from HFM DOT parts.

 

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Have read about the issues people have had with these, but having spoken to HFM I'm confident it will work well.

 

And, a little preview of what else is going on:

 

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Have also finalized the wiring harness documentation and ordered the materials for that. Pretty amazing, I simplified the harness as much as I could without going PDM, but I still need 600 metres of 20 and 22 AWG Tefzel... That's not even including the bigger gauge wiring for the higher current stuff. Lot of wire in a car!

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  • 1 month later...

Well, spent a bit of time working on things over the weekend. Got 10kg of dry ice to get the sound deadening out:

 

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Huge fail. Managed to get the back seat sections out easily, but it didn't touch the rest of it. Melted much faster than I expected it to, despite only being 14 degrees when I did it. So basically paid $100 to remove half a kg of sound deadening from the back seat = not great value. I suspect I just didn't buy enough, so it covered well in the back seat area where it is sort of 'cupped', but it didn't cover very well on the large flat areas and didn't get cold enough. Will get another 20kg at some point and try again, but my motivation for that has gone to 0.

 

Remembered there's a reason I stopped working on my car, so I decided to spend some time doing what I'm good at. I've had a Chinese fibreglass Nur Spec style bonnet and front bumper for a good 7 years that I've always intended to make in carbon and haven't had a chance yet. Or more accurately, I had a chance 3 years ago and spent $300 in bodyfiller getting the bonnet flat, 2 days painting it and wet-sanding/polishing it, $900 in materials and 4 days to make the mould............... Only for the giant globs of HORRIFIC quality Chinese adhesive they used to bond the inner and outer skins together to shrink drastically from the heat of the mould curing (only 60c) and leave me with both a badly dented fibreglass bonnet that looked like it had been in a hail storm, and a destroyed mould.

 

Ready to mould:

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f**ked (these dents are literally all over the bonnet and mould) :

 

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So yes, this project went straight back into storage and deleted from my memory. 

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But, I have always wanted a GTR front bumper and bonnet. So I pulled the bonnet and mould out of storage on the weekend. The bonnet is as f**ked as I remembered it to be. Not even an option to repair it and go again, because it would just happen again. Shit materials don't improve with time. Next option was to buy another bonnet and use that. But do you trust another Chinese bonnet to not do the same? I did not. So the only option for me: make it all myself.

 

Decided to use the f**ked mould to make an outer skin, using decent quality materials. Nice quality fibreglass infused with vinyl ester resin. Not the best of the best, but still better quality than any Chinese bonnet will use, and resin I know will take up to 110c so more than enough to survive the mould making process. Used a 3D PET core to keep it light while making it rigid enough to not need an inner skin. Skipped a gelcoat to keep it cheap, knowing it was going to need a lot of reworking to get it straight again anyway. Out it came, dents and all:

 

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Doesn't look too bad, but with primer on and blocked down you can see the dents a bit better (the greyish spots are the low spots):

 

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4kg of bodyfiller later, and it's sort of getting there:

 

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About ready for another coat of primer now, but before I do that, I decided the car is a race car now and needs a functional NACA duct not just a cosmetic out-of-spec one. The depth to width to length ratio on this one is way off, and the radiused corners cause flow separation, all of which mean it won't function properly and will cause a lot of drag/lift:

 

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So half an hour drawing one up to proper NACA specs with correct aspect ratio, a curved ramp, and most importantly sharp radii; and I sent the CNC to work while I went back to flatting the bonnet down some more:

 

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So now I just need to bang out a new duct off that mould, cut out the old one and integrate this one. Then I can reprime the whole bonnet and see how much more work I've got to do before it is straight again.

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4 minutes ago, robbo_rb180 said:

with dry ice i find around 20-30kg is right, weather dependent but put it in shopping bags so is easy to move around and shape to the tunnel/hard to get areas.

 

Yeh I did a bit of reading before attempting it and pretty much everything I read everyone said they used about 5-6kg to do their whole car. They must all be driving Austin Mini's because there's no way in hell they did anything bigger or newer than that with 5kg ? 

 

It isn't cheap though, that's for sure. Certainly didn't factor in spending the best part of $500 just getting the sound deadening out. I thought about just getting in there with a hammer and chisel, but then the $500 starts to sound more appealing haha. I don't know, I'll leave it for a little bit now and do something else. Engine bay needs a good clean while the engine is out. Have a bonnet to make from scratch. Etc.

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