R34 GTR Front Diffuser/Guard Liner questions.

[Kinkstaah]

Hello everyone.

I've recently started the research into R34 GTR front bits and running into eye watering prices.
On the plus site it looks like some places make 'replacement' fender liners for these cars. At eye-watering-but-less than stock prices.

I also noticed there's plenty of diffuser options available too.

What I would like to know is if my following assumptions are correct.

1) The OEM guard liners are actually only 'half' the liner. They go together with the OEM brake vents which are a separate item which looks to be quite a large 'panel' that is part of the liner. The GTR bumper has bolt holes along the front. I assume the ones in the vent correspond to the ones the OEM liner does not have (circled?)

 

2) The V-Spec front diffuser supplants the brake ducts in the above item. I am assuming these still work with the guard liners as there's no alternate part that I'm aware of. I don't see how they go together, so I'm making the assumption that they have to, somehow. I know the center splash guard is different on the V-Spec (and is the price of the damn diffuser alone).

How does the liner interact with this?

3) There's alternate front diffusers that do away with it all. Annoyingly, a lot of the clones and CF different ones... have no brake ducts on them. I like the idea of them though. My brakes get hot on the track. These alternate diffusers are a lot cheaper than plastic splash guards.

I'm assuming you don't have to/aren't supposed to remove guard liners to run a diffuser. I suspect that quite a few people actually do not run the guard liner because with a front undertray you're getting a lot of 'splash' guarding anyway, and most people remove liners given they're probably running a pretty aggressive setup with a diffuser at the front.

It would also be nice to know if anyone has ever run the 'reproduction' guard liners and know whether the fitment is OEM quality or "OEM Quality".
Example:

https://www.ebay.com.au/itm/356254671561
https://carbonetics.net/products/nissan-skyline-r34-gtr-plastic-front-wheel-arch-set

Is this knowledge still around?

[Duncan]

I don't know specifically.

I *do* know that it is very likely that historically most/all undertray replacements remove the inner liners and people just run without them. When you are hectic (or serious) enough to really want/need a different undertray, you are probably also running wider, taller or different offset wheels and the guard liners are the first thing that rub (or as I said in the other thread, they blow out at high speeds anyway)

Of course, that is before the pricing went nuts on R34s, nowdays it is much more likely people want/expect to retain the liners to protect their overall investment

[Kinkstaah]

2 hours ago, Duncan said:

I don't know specifically.

I *do* know that it is very likely that historically most/all undertray replacements remove the inner liners and people just run without them. When you are hectic (or serious) enough to really want/need a different undertray, you are probably also running wider, taller or different offset wheels and the guard liners are the first thing that rub (or as I said in the other thread, they blow out at high speeds anyway)

Of course, that is before the pricing went nuts on R34s, nowdays it is much more likely people want/expect to retain the liners to protect their overall investment

This is kind of what I expected given the use case. I took my liners out for track days too....

It makes me consider just getting a diffuser and not bothering with the arch liners themselves. For the most part I would like to avoid water/mud/jank splashing up from under the car onto the bottom of the engine, lines, wiring, etc etc. (but brake ducts are cool too).

Especially given this post on SAU here:

Where it's implied you have to cut them because the actual tub is different? Which is pretty damn worrying because that is where the liners rub in a GTR with wider wheels... I definitely won't want to pay $2000 for plastic then cut them up.

It also means said wider wheels rub on the tub in a GTT? FML. That said, I have found some evidence someone ran a 295/30/18 without scrubbing these liners. (and by extension.. the tub).