Aluminium back plates for AJP 4.5

Aluminium back plates for AJP 4.5

Author
Discussion

viperbluecerb

Original Poster:

69 posts

130 months

Monday 3rd June 2013
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The fibreglass back plates on my air boxes have collapsed quite badly. After trying to source some replacements, I decided that it would perhaps be better if I had a set made up from aluminium. Couple of pics below. They still need cutting to fit, will post some more pics once I'm done. Would be good to know if anyone else would be interested in replacing theirs.


ridds

8,191 posts

243 months

Monday 3rd June 2013
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You NEED trumpets on the inside. wink

Supateg

724 posts

141 months

Monday 3rd June 2013
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I was thinking of doing the same and getting Bryan Pendleton from the states to manufacture some Velocity Stacks to insert into a swaged collar to achieve an upgrade to the originals.

If you notice the original backplates go some way towards this end by the half velocity stack they incorporate.




Random24234

101 posts

147 months

Monday 3rd June 2013
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I would be quite interested in these assuming they don't weigh much more then the fiber glass versions. However they do need a velocity stack, here's a interesting guide on the design of them.

http://www.profblairandassociates.com/pdfs/Bellmou...

and a basic wiki summary, with said link above as a source.

http://en.wikipedia.org/wiki/Velocity_stack

Cerbieherts

1,651 posts

140 months

Tuesday 4th June 2013
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Yes i've already been looking into producing a batch of these myself, as a kit. The cheapest I could find the correct diameter and head-size trumpets for was £21 each, making them an extremely expensive prospect to produce. I have a local engineering place that says he can produce them but I'm still waiting on price. They will also need adequate heatshielding over the front, because heat transfer into the induction system through a big chunk of Alluminium sheeting and the trumpets will effect power.

viperbluecerb

Original Poster:

69 posts

130 months

Saturday 13th July 2013
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Progress has been a bit slow, but I managed to source some aluminium trumpets, although they needed a bit of modding, and will now have them welded up to the back plates I already made.


Supateg

724 posts

141 months

Saturday 13th July 2013
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Looking very good, hopefully torque and throttle response improvements with good mapping to be had.

Keep up the good work

Toby Tram

415 posts

164 months

Sunday 21st July 2013
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Very nice to see my old car being looked after!

Cheers

Adi

viperbluecerb

Original Poster:

69 posts

130 months

Saturday 27th July 2013
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Hi Adi! I know that you were the owner of the car prior to the guy I bought it off of. She was in really good condition and you can be safe in the knowledge that I will continue to make sure she wants for nothing and is kept driven :-) Use her as much as I can, just a sheer pleasure to be out in her!

Cracking on with the air boxes this weekend, should get them welded up on Monday and refitted. Picture below.

I was wondering if you have any further information on the history of the car during/prior to your ownership? I had a coil pack fail on me a couple of months back and replaced it myself, in true Cerb style it was a complete mission as the riv nut mounting plate was fecked to bits. However, in doing so, I had the ECU open to connect my diagnostics, and noticed an Austec racing sticker on top of the EEPROM, so I am guessing has been remapped at some point (my regular mechanic and another TVR nut who inspected the car before I bought it said that it is one of the strongest pulling 4.5s they have driven). Would be great to have any more info on work like this that is not documented.

Hope all is well with you,

Cheers,

Leigh

viperbluecerb

Original Poster:

69 posts

130 months

Thursday 15th August 2013
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Airboxes finished and installed in car. Couple of pics for those who are interested smile




ridds

8,191 posts

243 months

Thursday 15th August 2013
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Very nicely made.

anonymous-user

53 months

Thursday 15th August 2013
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Agreed they are very well made and I love owners coming up with workable solutions to TVR's shortcomings........

Can someone please enlighten me though.

The ACT carbon backpplates seem to have some form of trumpet due to the shaping of the intake, is there any benefit to having a trumpet proud of the backplate itself? I'm no CFD or AJP expert at all...trust me!!!! But as I'm looking at buying the ACT backplates, I'd like to know the best option.

chrisroe89

212 posts

130 months

Friday 16th August 2013
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viperbluecerb said:
Airboxes finished and installed in car. Couple of pics for those who are interested smile



Great finish mate, they look factory made (more Audi than TVR lol).

Jhonno

5,762 posts

140 months

Friday 16th August 2013
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djstevec said:
Agreed they are very well made and I love owners coming up with workable solutions to TVR's shortcomings........

Can someone please enlighten me though.

The ACT carbon backpplates seem to have some form of trumpet due to the shaping of the intake, is there any benefit to having a trumpet proud of the backplate itself? I'm no CFD or AJP expert at all...trust me!!!! But as I'm looking at buying the ACT backplates, I'd like to know the best option.
Simple terms.. Yes lots.

chrisroe89

212 posts

130 months

Friday 16th August 2013
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viperbluecerb said:
Airboxes finished and installed in car. Couple of pics for those who are interested smile



Great finish mate, they look factory made (more Audi than TVR lol).

NilsP

389 posts

116 months

Wednesday 23rd July 2014
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Hi Viperbluecerb,

I'm in the process in making my own backplates as well.
I was just wondering where you sourced the aluminum trumpets.

Thank you!

Kind regards,

NilsP

Mr Cerbera

5,031 posts

229 months

Wednesday 23rd July 2014
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Hi Viperbluecerb wavey,

Absolutely Cerberb thread thumbup

Well done, congrats and Best o' Luck.

Quick question: Did you make any calculations/measurements for rampipe length/radius ?

Ta !

Gerradi

1,522 posts

119 months

Thursday 24th July 2014
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They look fantastic ,would it be possible to spray them with a heating resistant paint as I think they may get quite hot & add a bit too much hot air into the TB ?

viperbluecerb

Original Poster:

69 posts

130 months

Thursday 24th July 2014
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Hi guys,

Thanks for the comments, highly appreciated :-)

I bought the trumpets of eBay... here is the link for the ones I purchased: http://tinyurl.com/pygvmqh

Cost around £100 for all eight. They will need modifying as they are too wide to sit together with the port arrangement, so I shaved around 1/4 - 1/2 inch off of opposite sides and welded them together in a row. The trumpets are OK quality but not perfect, but they worked well for me.

I didn't do any fancy calculations at all. I worked on the engineering principle that if it looks right, it probably is right. It certainly is a lot better than is was before and there has been no noticeable drivability change (I have not had the car remapped at all). I am sure flow is a little different to what it was before and the dynamics have changed, but not enough for me to really notice anything. The main reason for doing it was that the old ones had completely collapsed, rather than looking for a performance improvement. That said, I will for sure look at having the car mapped at some point in the future when time and funds allow.

As for transferring more heat into the intake air charge, I am not really convinced the impact is anything other than negligible, certainly no effect that has made itself felt through drivability or behavior. I am sure that if we get down to individual horses, AFR decimal points at different transient loads, etc., there is a change. But then instead of counting individual horses, I am just our driving her hard when situations permit and happy in the knowledge that no unwanted material is making it into the cylinders due to crazy large cracks between the original fiberglass back plates and intake hoses :-)




julian64

14,317 posts

253 months

Friday 25th July 2014
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To actually get power gains from that I would have thought you needed the parabola opposite each trumpet.