Trumpet Socks: How Bad/good/effective/rubbish Are They...

[Stu 18]

Hi all,

 

I trial fitted the carbs to the Mi yesterday, they're on a eeyore/sandy inlet so a little longer than the usual Longman type, and as a result ive got next to bugger all clearance at the bonnet end to fit proper filters from what i can tell..

 

So, firstly, does anyone else run this manifold with DHLA 45's and if so what filters do you guys use?

 

Im loathed to fit trumpet socks to be honest, but i figure something is better than nothing.

[Spiky 37]

i have TB's but have the same issue, my aifilter is upside down so now it fits

 

so instead of a ITG filter i have a GTI filter

[Sandy 191]

It's tight, but socks absolutely f*** the fuelling and power, seriously not recommended!

[wracing 19]

I never knew that but I guess it kind of makes sense, by placing something directly over the trumpet must almost negate the point of a trumpet right??

[Matt Holley 11]

It's tight, but socks absolutely f*** the fuelling and power, seriously not recommended!

 

Dont hold back Sandy, tell us what you really think of them

 

A pic of the carbs fitted might give a better idea, Ive got an itg domed filter up the correct way on mine with a longmans manifold so up the other way would give a bit more room.

Edited July 8, 2009 by matt holley

[swordfish210 20]

It's tight, but socks absolutely f*** the fuelling and power, seriously not recommended!

 

Second! Socks are good for keeping dirt out, but they also keep the air out, not ideal.

[Paul_13 212 1 Cars]

Tights and cable ties?

[GilesW 41]

Socks funk the pulse tuning of the trumpt/intake length.

 

In real life - mates mk2 escort, all steel engine on carbs. Rolling road tuned - 20bhp lost when socks were on (back to back run's as the socks took all of 20 seconds to fit).

 

Question for people - much research been done on here on what inlet lengths work well for carbs and TB's on the mi16? ie what length for road going revs?

[Sandy 191]

I've found some very good results from around 370-380mm, but it depends on many factors and above all you'll need a special inlet to do that.

[rapidcossie 0]

I have run socks on throttle bodies and have down various power runs on the rollers with wideband connected etc and power and fuel does not alter with or without them.

 

Maybe carbs are different?

[Miles 331 1 Cars]

I have to agree, Sock's are cr*p and on carb's on Bodies normally reduce power a fair amount

[sideways danny 0]

tried a few different things to see how bad socks really are. We found on a ITB equipt clio 172 they lost approx an extra 4bhp over a domed sausage filter, which caused about 4-5bhp loss in itself. So socks are not the best option, but if you really are stuck for space, they're "OK". I wouldn't touch them on anything high compression though, they WILL get sucked in

[Cameron 16]

Yeah those panel filters aren't the best, but at least they kind of act like a small air box. What you need is a dragster-style bonnet scoop.

[jerseypug 1]

i gained 40 bhp on the rolling road by removing the pipercross filter socks from my gti6. i am going to make an airbox and cold air feed. i tried stockings but they only last about 1 week before they get large holes in them.

[Stu 18]

Thanks guys, you've pretty much confirmed my thoughts..

 

Sandy: Out of interest, what have you or colin used in the past air filter wise mate?

 

Ill be final fitting the carbs later so will have a better idea of exactly how close it is, even with the stock trumpets ive had to notch the slam panel, and thats without a filter!

 

Its not this that worries me overly though, its the height issue, im fairly sure the backing plate for the air filter will foul the bonnet.

[sideways danny 0]

i gained 40 bhp on the rolling road by removing the pipercross filter socks from my gti6. i am going to make an airbox and cold air feed. i tried stockings but they only last about 1 week before they get large holes in them.

 

you didn't pull them right down tight over the end of the trumpet did you? They're meant to just go over the end by about an inch. I've pout a lot of cars on the dyno with socks, and none have lost anything like that

[Sandy 191]

Thanks guys, you've pretty much confirmed my thoughts..

 

Sandy: Out of interest, what have you or colin used in the past air filter wise mate?

 

Ill be final fitting the carbs later so will have a better idea of exactly how close it is, even with the stock trumpets ive had to notch the slam panel, and thats without a filter!

 

Its not this that worries me overly though, its the height issue, im fairly sure the backing plate for the air filter will foul the bonnet.

We use ITG bar filters usually and when I've tested with and without, it's shown 2-3bhp difference if anything at all. The socks, single or dual, however fitted have produced pretty severe effects on every engine I've tried them on. On carb engines it's worst of all; one 1360 I did revved freely without them, but would not go over 5500rpm on the road with them fitted, it was alarming until I realised what the problem was! Collapsing is what produces the worst effects, but the main issue, as you'll witness if you try them on the flow bench, is that the trumpets flow air principally over the edge, which is where the foam is on the socks.

 

It depends exactly which of our manifolds you have and space or carbs is severely limited. Really the only way to get a decent filter in is:

Run a plastic bonnet with minimal internals (pins fitted through the slam panel bolt hole to reduce bowing)

Cut back or remove the slam panel

Drop the rad.

[engine killer 6]

We use ITG bar filters usually and when I've tested with and without, it's shown 2-3bhp difference if anything at all. The socks, single or dual, however fitted have produced pretty severe effects on every engine I've tried them on. On carb engines it's worst of all; one 1360 I did revved freely without them, but would not go over 5500rpm on the road with them fitted, it was alarming until I realised what the problem was! Collapsing is what produces the worst effects, but the main issue, as you'll witness if you try them on the flow bench, is that the trumpets flow air principally over the edge, which is where the foam is on the socks.

 

It depends exactly which of our manifolds you have and space or carbs is severely limited. Really the only way to get a decent filter in is:

Run a plastic bonnet with minimal internals (pins fitted through the slam panel bolt hole to reduce bowing)

Cut back or remove the slam panel

Drop the rad.

 

I use socks since there isn't enough room for a proper airbox. I understand an airbox can allow pulse tuning but what if the air is force feeded (slightly) instead of by vacuum (intake stroke)? Is an airbox still give a significant difference? Would love to hear you guys comments, thanks.

[Sandy 191]

It's rare to genuinely pick up power by using an airbox with TBs real time. On a rolling road you might well see an apparent improvement because of the lack of air movement in the engine bay, but out on the road you will invariably see better air delivery (reflected in AFR) without a box. One of my friends has been developing airbox designs on the dyno and in the cars for very high spec XE engines in RWD Escorts and although I can't give away any detail, it's been extremely difficult to work a design that will fit and not impede the overall spread of power; let alone bring improvements. You won't generate any force feed to speak of, but a good design can reduce the pressure drop.

[andyjstone 6]

I tried using the sock filters, but they got sucked into the trumpets so I ditched them and got ITG to make a custom bar filter to fit - I just gave them the clearances all round and it turned up with a few mm spare around the edges - not cheap, but it works great.

 

Edited July 10, 2009 by andyjstone

[jonnygoodhand 0]

On carb engines it's worst of all; one 1360 I did revved freely without them, but would not go over 5500rpm on the road with them fitted, it was alarming until I realised what the problem was!

 

Was that mine, Sandy? I seem to remember you mentioning something similar at the time.

 

I'm currently using these: http://cgi.ebay.co.uk/ws/eBayISAPI.dll?Vie...tem=20033051194

Edited July 10, 2009 by jonnygoodhand

[philfingers 5]

I fitted some pipercross trumpets socks to a 1700 XF in a MkI XR2 we used to run on Navigationals in Scotland. It was full BVH, twin 45s etc. when it went to the rollers the guy couldn't get it to run above 3500rpm. He wasn't sure what it was, he thought initially (I wasn't there when it was setup) that there was some programmable limiter setup at 3500, it was like it hit a soft limiter. Anyway he removed the socks and once jetted it made 139bhp at 7k. the socks were f****g useless. not helped by the fact that in that car the trumpets sat about 30mm from the bulkhead (it made some induction noise in the cabin!) but they were useless. In the end we ran it without with no detrimental effect

The socks were brand new and pipercross weren't interested in a refund

[Stu 18]

I tried using the sock filters, but they got sucked into the trumpets so I ditched them and got ITG to make a custom bar filter to fit - I just gave them the clearances all round and it turned up with a few mm spare around the edges - not cheap, but it works great.

 

 

That looks cool mate, problem with mine is im a bit further forward than that..

 

Here's how tight it is...

 

[Spiky 37]

who needs a slam panel

 

[sideways danny 0]

agreed, you've already got bonnet pins, so ditch the slam panel