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GTiR Plenum backplate in billet
jeffw - 1/2/17 at 10:45 AM

My new billet plenum backplate has arrived. Think it looks rather nice





[Edited on 1/2/17 by jeffw]


Dick - 1/2/17 at 12:02 PM

Looks very nice if I must say so myself


jeffw - 1/2/17 at 12:11 PM



Thanks to Dick


bi22le - 1/2/17 at 12:49 PM

Is this going to have trumpets going through as the inlet mouths are not turned.

I can see that you have rubber o rings to seal it so I cant work out how your are going to smooth the air flow into the ITBs.


jeffw - 1/2/17 at 12:55 PM

19mm trumpets as before with the other backing plate


jeffw - 1/2/17 at 01:15 PM

although you don't actually need them with forced induction. A number of big power cars don't use trumpets in their plenums


Dick - 1/2/17 at 03:38 PM

The o ring are to seal the back plate to the throttle bodies as jeff and I both think we need to ensure that no boost pressure is lost, the bore of the plate is an exact fit to the throttle bodied so no step is present so its just like the throttle bodies are a bit longer, the trumpets are also and exact fit so its the trumpet length plus the plate thickness onto the original itb's. If you run your finger over the joints you can feel the joint but cant detect any step


CNHSS1 - 1/2/17 at 03:51 PM

*cough* big tart Jeff *cough*

Craig


richardm6994 - 1/2/17 at 04:36 PM

Very nice indeed jeff!
May I ask what depth you've gone for on the internal step to increase volume plenum?.

I think you've already seen my efforts on here and facebook (the blue charger on the silvertop zetec) and I went for a 16mm depth, but yet to see what the rolling road results are like.

I'm currently planning another one now for an ST170 engine in a GBS zero. This time however I'll be machining with bell mouthed / trumpet shaped inlet holes.


jeffw - 1/2/17 at 04:42 PM

quote:
Originally posted by CNHSS1
*cough* big tart Jeff *cough*

Craig


I'll be having words later ...


jeffw - 1/2/17 at 04:44 PM

quote:
Originally posted by richardm6994
Very nice indeed jeff!
May I ask what depth you've gone for on the internal step to increase volume plenum?.

I think you've already seen my efforts on here and facebook (the blue charger on the silvertop zetec) and I went for a 16mm depth, but yet to see what the rolling road results are like.

I'm currently planning another one now for an ST170 engine in a GBS zero. This time however I'll be machining with bell mouthed / trumpet shaped inlet holes.


Your efforts are always interesting and well done. The step is 10mm from memory but could be much larger but at the expense of machining a very large billet to get the increase depth.


richardm6994 - 1/2/17 at 05:02 PM

Thanks Jeff,
The billet isn't too expensive, I think the piece I used on the blue charger was about £20 and the thicker one (to allow for the bell mouths) I'll be using for the ST engine will be about £30........only downside to these is loads of bl00dy swarf everywhere!!

They polish up nice though!


CNHSS1 - 1/2/17 at 05:55 PM

Anything billet is worth 10 pit-pose points and .2s on the track for sure


jeffw - 1/2/17 at 06:22 PM

lol


SPYDER - 1/2/17 at 07:44 PM

Nice work. I'd have put pockets in between the holes on the back for lightening. And even more bling! I might even have tried machining integral bellmouths!
I did 20 years in CNC machining but haven't done any for a while. Its highly satisfying turning a blank into something like your plenum. I've even considered buying a small machine for the garage.
Now where are those roller barrel throttle sketches...?


richardm6994 - 1/2/17 at 08:18 PM

CNC = LOL 😀
The trick is machining stuff the old fashion way and people thinking it's been done by CNC.

For the intergrated bell mouths I'm doing on this latest gtir back plate, I'm machining a bespoke cutter to make sure the bells are all the same shape and size. This in itself is hours of work but a lot more satisfying than g-code (which I have to do from time to time at work) or catia.


jeffw - 1/2/17 at 08:38 PM

Much as I enjoy a bit of CNC billet it is about going faster and not really about looking good, although the new body kit will do that (and shocks/wheels !)


jambojeef - 1/2/17 at 09:40 PM

http://www.profblairandassociates.com/pdfs/RET_Bellmouth_Sept.pdf


nick205 - 2/2/17 at 11:04 AM

quote:
Originally posted by richardm6994
........only downside to these is loads of bl00dy swarf everywhere!!



True - clearing up the swarf can be hard work!


SPYDER - 2/2/17 at 04:09 PM

quote:
Originally posted by nick205

True - clearing up the swarf can be hard work!


In my last job we machined some "swing wing" hinge prototypes from the largest ally billets I have ever encountered.
The largest was about five feet by three feet by about 18 inches. We had to modify the bed with indexing pins so that we could move the billet along.
Ninety five percent of it was reduced to swarf. This was on an open machine too.


jeffw - 4/2/17 at 12:18 PM



On the car...


gaz_gaz - 4/2/17 at 01:53 PM

Very nice..

Did you build the car from scratch Jeff or did you buy and modify modify modify?


jeffw - 4/2/17 at 03:02 PM

Bought it about 10 years ago with a Silver Top on carbs....changed a bit since then


richardm6994 - 13/4/17 at 09:44 AM

Here is my home made effort now it's finished. Started out as a 30mm thick ali plate.

The bell mouths have turned out alright as well.




jeffw - 13/4/17 at 09:54 AM

That's cool as well. Nice job.


Sam_68 - 13/4/17 at 11:44 AM

Here's ours - this one is for a supercharged Duratec:





jeffw - 13/4/17 at 11:53 AM

http://www.alitechprecision.co.uk/carbon-fiber-plenum


Sam_68 - 13/4/17 at 12:47 PM

quote:
Originally posted by jeffw
http://www.alitechprecision.co.uk/carbon-fiber-plenum


Yep, we commissioned it. They've done a billet combined engine/supercharger mounting bracket for us, as well.


richardm6994 - 13/4/17 at 01:46 PM

For a second then I thought you'd machined that yourself by hand and was deeply impressed......

[Edited on 13/4/17 by richardm6994]

[Edited on 13/4/17 by richardm6994]


Sam_68 - 13/4/17 at 02:00 PM

Hell no!

Alitech share their building with a company called Express Composite Solutions - between the two of them they have an impressive capability for turning out CNC machined aluminium and composite moulding work. Nothing like as expensive as you might guess, either.

The chap who did our plenum has a very impressive Sylva Striker, I believe; I've a feeling he's a member on here, so he might pop in to say hello!


jeffw - 13/4/17 at 02:04 PM

The main man at Alitech did all the brackets for my TTS kit and then all the fab work on the intercooler/rad setup.


Sam_68 - 13/4/17 at 03:57 PM

Yes, he was Ex-TTS before he set up on his own, as I understand it, and they still use him for their CAD work?

Again, TTS are on the same industrial estate, just around the corner.


ETA...which reminds me, indirectly: do you have any sort of top brace or steady-bar on your engine, Jeff, or do you just rely on the usual engine mounting positions?

[Edited on 13/4/17 by Sam_68]


jeffw - 13/4/17 at 05:01 PM

Just the engine mounts as per normal. Darren (at Alitech) is a good guy, worked at Omex as well.


Sam_68 - 13/4/17 at 05:10 PM

Omex is how we found him, IIRC: we got our engine from them, and Richard recommended him.

Reason it reminded me was that Darren has (or had?) a quite powerful supercharged Striker.

He suggested that a top brace was essential for our car (circa 320bhp supercharged). I wasn't totally convinced, as I've always regarded the rear tyres as a 'fusible link': you can only transmit as much torque to the chassis as your tyres can transmit to the road. Still... I came up with a design that increases the torsional stiffness of the front end, and looks quite sexy to boot, so we're fitting one, but if you're managing without one it's obviously not an issue!