A few guys warned that the Rear Diffuser would act like a parachute, other advised that the fuel tank would deflect the air under the diffuser.

I found out the answer the hard way I've been doing alot of motorway work recently and it seems the high speed and increased road spray had taken it's toll. The diffuser had split where the larger section joins together.







This post is not meant as a 'dig' against HT Autos, just a bit of info on my part.

Next question is where to go from here

 

im sure they will sort something out mate .

 

I would definitely speak to HT Autos as i'm sure they will sort for you.

Regardless it would be good to know if this was Carbon Fiber or Fiberglass?

 

Mock carbon like mine....

Which has also managed to shake a couple of nuts/bolts loose over the year.

dunx

 

i was going to buy one of these but didnt like the joining so i bought the apr one which is a full piece item.

 

It was was a mock carbon one. With this and me losing the top diffuser (see below) I'm tempted to leave it all off and spend cash on suspension and power mods. There nothing like to sound of your hard earned flying off the car

 

Leave it all off i would say, unless you go full carbon and if your going carbon make sure you double check that Epoxy Resin was used to layer/build it.

 

This is the reason i did not buy one because i though i might catch the air. The cusco ones are smaller and have alot more of a brace to support them, i think have a look... bummer all the same.

Charlie

 

Gutted for you! Did they cause any other damage to the car when they flew off?

 

The top diffuser hit the rear wing on its departure, causing a slight scratch. There's no damage to the bumper as far as I can tell, I'll take a closer look when I remove the bottom diffuser.

The other damage was to my wallet. Never mind, lesson learnt

 

Gutted for you mate, Red's got both of these and his are still on for the moment!! Think he used super duper glue on his vortex generator!!

 

O dear. I was going to order both this month!

I was concerned about airflow with the diffuse, if it affects downforce at all at high speeds?

I guess this looks like a bad idea now!

Any reported issues on the classics? Are they the same fitment as on the classics?

 

Cheers. Red's got different diffusers as his spikes are thinner, which I was tempted to buy. I think I'll leave the stick on bits for now though and start on some other mods.

 

The upper diffuser did reduce the amount of vibration in the rear wing. I don't think the lower one added anything apart from looks.

 

I did consider sourcing some "mud-flap" like material to force the air under mine, but as it's limited to 155 mph it hasn't been a problem,

dunx

 

what a mess!

I've had mine on for a good few years and its never budged! Get another one (cheaper than getting your roof painted) and Tiger seal is your friend!

 

Bloody hell, still haven’t fitted my rear diffuser yet, will look into adding so strength when i do, any ideas ?

 

A strip of Alu along the leading edge should help. The weekness seems to be in the join of the larger sheet.

(it's taken me 4 attempts to post this reply )

 

Very poor, That is not good at all. I think if you have one of these fitted now is the time to go and check it out for any cracks or damage.

 

Not so much concerened of increasing performance but not decreasing it... Any tests performed when these things are designed?

 

They come as std on hawkeye cars and I've not heard of one disintegrating yet.
Summat to do with the HT design itself has caused this.

 

The hawkeye one is only in the centre of car, not all the way across.

Where the diffuser fixes to the wheel well is solid, it was the join that split and failed. If you have one fitted it'll be worth keeping an eye on it, especially with all the wet weather right now.

 

When they first ran the group buy they were tested on a few cars at motorway speeds without any issues but not long term tests,
Could they be made with some sort of vent on them to help let the pressure out,
To the OP did you hear it loose at all/any noises etc ?

 

Nope, no noises. The first I knew about it was when a driver behind me started flashing his lights!

There is a vent above the number plate but probably not large enough to cope with the larger build up of pressure.

 

This was the question I asked when Mark at HT first posted up the Group Buy back in June/july. He had sad it had been tested up to 100 mph but did say if you were doing track day that you should use extra fittings.

I stuck with the original one on my 07 STi in the end.

Hope you get it sorted, I'm sure Mark will sort something out.

 

Are Ht autos aware of this failure...??????

Surely a reply to this thread from them would be a sign that the problem is being addressed.....and that they know about it.

 

Mine has survived a trackday fine, but if you lose a couple of bolts.....

Mine is still on, (just), but obviously would result in the same end result.

IMHO

dunx

P.S. I'd like to be able to afford an APR carbon diffuser