Equal length inlet tracts rv8 twin turbo

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Twinturbotr7
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Equal length inlet tracts rv8 twin turbo

Post by Twinturbotr7 »

Is having truly equal length inlet tracts any use on a forced induction rv8 , I came across an article on USA forum where a chap has cc'd his inlet manifold and trumpet base and Has found that the standard trumpet lengths are far from being correct , I've currently got my trumpets pulled out of the plenum base and it wouldn't take much to correct this and would be totally free , I'm only running a low boost setup so any extra free Bhp I can pick up I will gladly take , this chaps work looks spot on and well thought out but he's not running FI

http://forum.britishv8.org/read.php?6,33428,page=3

Anyway have a read and let me know what you lot think , hope I've not broken any rules putting a link to another forum
Thanks Nick



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Re: Equal length inlet tracts rv8 twin turbo

Post by DaveEFI »

Not sure inlet track resonance is as important with forced induction?
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stevieturbo
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Re: Equal length inlet tracts rv8 twin turbo

Post by stevieturbo »

If it improves things n/a then generally it will also improve boosted.


But is it really worth the time/hassle for what will probably be miniscule gains ? That's up to you.
9.85 @ 144.75mph
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http://www.youtube.com/watch?v=XgWRCDtiTQ0

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Re: Equal length inlet tracts rv8 twin turbo

Post by DaveEFI »

My reasoning - not knowing anything about turbos - was that you'd set you'd design your boost to give the figure you wanted more or less across the torque band, and not rely on resonance to peak it up over a narrow band?
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Re: Equal length inlet tracts rv8 twin turbo

Post by Twinturbotr7 »

Thanks for the replies ,ok so Having equal intake runners is not important on a n/a motor,

The plenum I'm modifying now has a forward facing Thor throttle body , the standard trumpet height and arrangement in my opinion is masking my throttle opening for it to flow from my throttle opening into the trumpets ,
I did consider having a blended base but I've milled aprox 30mm from the bottom of my trumpet base and and a further 10mm from my inlet manifold this will have shortened my all my inlet tracts by 40mm for this reason I was planing on installing some trumpets , seeing as the individual lengths are unimportant can I just set all my trumpets level at say maybee 40mm heigh , Heres my plenum ImageImage
If you look at this picture with the standard trumpet arrangement you will see there very close to the opening and and as a consequence I think will flow poorly,Image if you look at the next picture you will see it with cut down trumpets in , do you lot think this is a better arrangement? I think with the lower trumpets and all at one height it should flow much better ?? Image and here's a picture of my proposed trumpet heightsImage it's just a mock up nothing glued in , I've got loads of spare trumpets kicking around and have done just to see what looked like and so you lit could see what I'm doing , I've
Found somewher I can get some cheap spun alloy trumpets with bigger flairs on and was going to get them welded in save using the steel ones

Thanks Nick

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Re: Equal length inlet tracts rv8 twin turbo

Post by stevieturbo »

Trumpet to lid clearance....I'd certainly go for the lower height trumpet.

You could go to the trouble of staggering the trumpet heights as per OEM intakes, but I wouldnt get too worked up about it.
9.85 @ 144.75mph
202mph standing mile
http://www.youtube.com/watch?v=XgWRCDtiTQ0

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Re: Equal length inlet tracts rv8 twin turbo

Post by ChrisJC »

For me, I would remove the trumpets entirely. Normally, the air enters the plenum from the side at the top, i.e. above the trumpets. With your mods, it will have a heck of a convoluted path to get into them. I wonder about how the airflow will vary from cylinder to cylinder with that setup.

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Twinturbotr7
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Re: Equal length inlet tracts rv8 twin turbo

Post by Twinturbotr7 »

I'm a bit worried about removing the trumpets compleatly as I've milled 10mm out my inlet manifold and 28mm off the bottom of the trumpet base so my inlet tracts are 38 mm shorter than probably anyone else ,we know a normal height plenum with a blended base works but if I had blended base with my 38mm less inlet tract to start with I'm not sure how it would behave never heard of anyone with blend base on milled out manifold ?? so what I'm thinking of doing is having very short 38mm height trumpets ,that should make up for what I've milled out and have them set all same height so the air should flow over them all quite well ,hopefully this should work as well as a blended base , I've bought some aluminium trumpets with a slightly bigger inside diameter of 40mm and a bigger flare on the top I plan on filling these
nick

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Re: Equal length inlet tracts rv8 twin turbo

Post by Ian Anderson »

http://www.mez.co.uk/ms12-new.html

What about a blended base as shown here?

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Re: Equal length inlet tracts rv8 twin turbo

Post by DaveEFI »

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Twinturbotr7
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Re: Equal length inlet tracts rv8 twin turbo

Post by Twinturbotr7 »

Ian Anderson wrote:
Wed Mar 07, 2018 6:27 am
http://www.mez.co.uk/ms12-new.html

What about a blended base as shown here?

Ian
I hadn't thought about one of those 💡,
but looking at it I think because of my throttle body positioning I fear it will Be to close to bottom of my throttle body and would mask a lot of the opening, I might also loose to much penum volume, I've already lost the volume of the big bit on side I've chopped out the side I will post up some pictures of my plenum in the making in a minute when I've found the pictures out and you will see what I mean

Thanks Nick

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Re: Equal length inlet tracts rv8 twin turbo

Post by Twinturbotr7 »

DaveEFI wrote:
Wed Mar 07, 2018 9:08 am
You might find this of use.

http://www.wallaceracing.com/runnertorquecalc.php
Hi Dave Thanks for that👍 not wishing to sound to thick , I fear it might be over my head, I'm great at fabricating stuff etc but don't have a clue as what to put in half the boxes in the algorithm tables ,# of induction wave not clue what that is ??? Intake runner area ?? Don't know iow to work that out ?? The peak torque well the cars not that heavy so don't need loads low down torque but thats about as much as I know on that one ,And also my cam duration I don't actually know what that is to hand ,I had the cam from John eales he said it would be ok for my application i to took his word for it ,he also dialed it on for me ,
I'm great making things and problem solving and enjoy it but the maths behind this kind thing I'm not to good at ,we all have our strengths I suppose
Nick

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Re: Equal length inlet tracts rv8 twin turbo

Post by Twinturbotr7 »

Ok here's a few pictures of my plenum and how I made it it might explain why some solutions might not work
Ok so here a picture of Thor throttle Body in font of a standard plenum as you can see it's far to heighImage
You will see in these next pictures what I did next I used a standard trumpet base turned it upside down and trimmed the plenum so it would fit in it this gave me the extra height for the throttle body's infact i used 2 bases cut up and joined up so I could have the spare ports on both sides ,Image as you can see on this pic ybw throttle body now fits Imagethe problem I had with this now Is my plenum is to high so I got yet another one of my spare trumpet bases ground out the fittings had the bottom bits tig welded and took to my machinist who milled 14mm out the top to compensate for what I welded on to the plenum top , he also milled 20mm of the bottom and a further 10mm off the top of my inlet manifold itself ,Image Image in this photo you will see I cut sides out of spare plenum so I could have some patches that were the correct curve then had all welded up , ImageImagethen had all welded upImage Imagenow the hard part trimming all the rubbish out the way Imagethen I made up a billet wedge shaped adaptor and had this welded to the front of the plenum ImageImageImageand I've been grinding down all the welds to make it look as factory as possible ImageI've sincere had another 8 mm milled out of my trumpet base to aid throttle body to intercooler alingnment here's a picture of it in place I've still got some more grinding down to do but it's getting there,😀Here it is in place in my tr7 Image hope you lot like it ???
all fabrication done by myself the welding was done by rod at tjr reconstruction just outside Lichfield

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Re: Equal length inlet tracts rv8 twin turbo

Post by stevieturbo »

You're worrying over nothing....keep it simple.

The short intake trumpets will work fine.
9.85 @ 144.75mph
202mph standing mile
http://www.youtube.com/watch?v=XgWRCDtiTQ0

Twinturbotr7
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Re: Equal length inlet tracts rv8 twin turbo

Post by Twinturbotr7 »

stevieturbo wrote:
Wed Mar 07, 2018 10:33 pm
You're worrying over nothing....keep it simple.

The short intake trumpets will work fine.
Thanks I just like to do things right first time
Hence all my stupid questions I've been asking on here

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