Going To Play With Inlet Tract Length

[smckeown 1]

I have read a lot tonight about inlet tract length. Unfortunateloy most of the posts are about mi16's which have a head port inlet length of 80mm, does anyone know the length for the 8v ?

 

I'm going to follow TT205's proven example here

 

http://forum.205gtidrivers.com/index.php?a...post&id=910

 

He found this to be the best for max torque on his 8v

 

So I have ordered the filters from ebay (4 for £38 new..bargain). Next up is the ali tubing. Anyone know where I can get this from ? I'd assume I need 45mm in diameter ?

 

cheers

sean

[Sandy 191]

Alloy scaffold bar can be machined to size.

[smckeown 1]

Does anyone know the head inlet tract length for an 8v ?

[smckeown 1]

any idea where i can order that sandy ? I was thinking maybe some old exhaust pipe also ?

 

merlinmotorsport sell 45mm O/D but not I/D tube Wierd as it says it's for induction systems ? I assume i MUST have 45mm I/D ?

 

 

I plan on making a thegth say 120mm fix to my TBs, then use hose and clips to join different lengths. The only issue I see with this type of extension is the bell mouth is not open. I read on the jenvey site this was important, but abviously TT205's experience showd it was not so.

 

Anyone else used this method successfully of tuning inlet tract width ?

 

cheers

sean

[Sandy 191]

Go to a scaffolders yard and ask if they have any scrap alloy poles, they'll think you're a pikey though.

[sonofsam 5]

http://www.smithmetal.com/products/catalogue.asp

[nick 3]

This looks useful,

 

ally/stainless tubing on ebay

 

Nick

[sonofsam 5]

This looks useful,

 

ally/stainless tubing on ebay

 

Nick

 

Yep can recommend that guy also, supplied me with some boost pipes:D

[smckeown 1]

This looks useful,

 

ally/stainless tubing on ebay

 

Nick

 

Nice one nick, have emailed him to see if he can make me some custim trumpets.

 

I'm thinking I should get them make with say a 30-30deg bend downwards to aim towards the middle of the grill. As looking at tt205's version at the top, i'm concerned the top of the filter will be restricted by the bonnet, especially as these filters draw air from the sides. What do people think ? Alternatively I could experiment with some sock filters that draw from the front also, but i've heard bad things about sock filters. As an alternative to getting the inlet tract made with a bend, I could cut the bonnet and fit a small scoop ?

 

thoughts ?

 

cheers

sean

[chunkymonkey 0]

why not try to get carbon tubes on your quest to saving more weight.just a thought

gaz

[smckeown 1]

why not try to get carbon tubes on your quest to saving more weight.just a thought

gaz

 

i'll keen an eye out cheers

 

I've seen these hose joiners for £11 delivered 45mm and ~20cm long. Hopefully I can find cheaper than that.

 

If all extenders were wrapped in cool-it materian, other than weight, what would be the difference in materials used, i'm thinking hose is good to experiment with lengh wise, before comitting to get some custom made with proper fixing for TBs and profile ends

[chunkymonkey 0]

try here for the carbon tubes............http://carbonfibretubes.co.uk/

[nick 3]

Sean, have a look at the thread I have just started "Custom machining online" it could be very useful to someone such as yourself.

 

Nick

[TT205 42]

Start with exhaust pipe, find the optimum length for you THEN have them made of Ali or you are unecessarily wasting £££

[smckeown 1]

yeah went around the back of my local exhaust place on sunday but didnt find anything useful Must try and think more like a pikey.....hmm maybe eye up my neighbours cars

 

I'm confident I can make the adapers to fit to my TBs, just need to secure some cheap pipe for experimenting first....any ideas lads....

[TT205 42]

How about go into an exhaust place and offer to buy 4' of straight pipe

[sonofsam 5]

The real fun begins when you try and cut it in a straight line with nought but a hacksaw.

If you know anyone with a compound cutting chop saw or bandsaw, nows the time to make 'em your mate:D

[smckeown 1]

How about go into an exhaust place and offer to buy 4' of straight pipe

 

I work away mon to fri, i never get the chance to do stuff like that, hence replying on the web or the wife to source my bits

 

The real fun begins when you try and cut it in a straight line with nought but a hacksaw.

If you know anyone with a compound cutting chop saw or bandsaw, nows the time to make 'em your mate:D

 

I'll mock some up myself to prove the length and ensure there is enough space available etc., then i'll get the end result made up professionally

[smckeown 1]

I'm in discussions with that guy from ebay in supplying cheap 45mm I/D tube to get me started with the experimentation.

 

I've been using the Intake Runner Length Computation by Bowling and Grippo and from what I can tell my current inlet tract is only benefiting from the 4th harmonic. If I add 4cm more I should also benefit from the 3rd harmonic (This is the inlet length TT205 is running i estimate).

 

To benefit from the 2nd harmonic, i'd need to add something like 31cms more than my existing length (i.e. a hell of a lot). So the only way I can think of getting an inlet tract that long is to bend the tune downwards 90 degrees, raise the rad back to it's usual height, and get the air flowing to the bottom of the splitter to feed the end of the inlet. Do people thing this is completely silly ?

 

It's certainly an education this area....thanks to all that have posted links (both here and previously on the forum regarding pule tuning)

[rich_w 0]

To benefit from the 2nd harmonic, i'd need to add something like 31cms more than my existing length (i.e. a hell of a lot).

 

Would a airbox and ducting like Jon has, work?

[petert 585]

Why not use 50mm pvc tubing? The ID won't be quite 45mm but you can alter the lengths easliy on the dyno.

[smckeown 1]

I had a look in our local B&Q last weekend and they didn'thave anything suitable. I thought the resonance properties of platsic and ali were different, so if you found the optimum using OVC, it may not be right in ali ? Have you successfully used this approach peter ?

[petert 585]

No, but the dyno dude around the corner does.

[tom_m 0]

try here for the carbon tubes............http://carbonfibretubes.co.uk/

 

fwoar, bet they're not cheap!

 

i wonder what kind of internal pressure they can stand up to... carbon fibre boost pipe anyone???

[smckeown 1]

i'll set the wife another 'Challenge Aneka' then.... Sounds ideal I'll cut up some existing trumpets so I have somehting to attach the PVC pipe to, then start off long and test various lengths cutting off a few CMs at a time..

 

I assume a test like performing 50-70 runs in 4th, 3 times in a row and taking the average over same piece of road would be a suitable way to test the effects on power ?