F7R TB setup

Affiliate Joined: 28 Jan 2005 Posts: 360

Chris, Ben, Craig or anyone else:

As you know our 19 is running the F7R-710 lump. I've just ordered a set of tapered 48-45 TB's but i'm unsure about trumpet lengths. As I understand it the longer the trumpet the better but... and here's where things differ slightly... we're not going to be running a foam "dome" filter setup and instead are opting for a sealed box setup which will be filtered at the induction source behind the front bumper will we be ok running a 45mm trumpet in conjunction with this setup over a +50mm or will it have an adverse effect on power?

Cheers

Mick

Retroholic Joined: 23 Dec 2005 Posts: 3315

longer the trumpets the more top end power right?

and shorter is more low down grunt?

i dont have a great understanding of it on cars but this is the theroy on race bikes

Affiliate Joined: 28 Jan 2005 Posts: 360

Well my thinking is similar... longer inlet track with shorter trumpets = balancing out good all round power but I just wanted the feedback form the experts Wink

Retroholic Joined: 23 Dec 2005 Posts: 3315

sorry i aint in that group lol but i no that on a bike they put two shortones on the 2 cylinders that fire first for the low down grunt at low revs then longer on the others for when its singing at high revs,

your looking for a happy median right between power and torque? soz im learning

plus i dont no if on a ar they need to be all the same lenght its prob a trail and error thing

Affiliate Joined: 28 Jan 2005 Posts: 360

Well the bodies themselves will be the same length but i'm thinking about fitting 45mm trumpets. The only problem is that i'm not paying for PACE to make me a 3 core rad for +Â£500 and fitting a foam filter behind the rad will syphen off power so i'm shielding the inlet with a box and increasing the inlet track to compensate... I'm also learning so don't worry too much mate. I'm sure Chris will be here to call me a twat soon Razz

Retroholic Joined: 23 Dec 2005 Posts: 3315

dont use foam

Affiliate Joined: 28 Jan 2005 Posts: 360

Pics a little on the small side mate Wink

Retroholic Joined: 23 Dec 2005 Posts: 3315

sorry i cant make that one bigger but it spat back a flame and caught fire

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

As long as the airbox is a good desing and free flowing then theres no reason that the box will be any hindrance at all.

Your idea sounds about right.

As long as the cams are not to wild etc then a shorter inlet tract will not be an issue. The meganes is slightly shorter than the 19's anyway btw.

Affiliate Joined: 28 Jan 2005 Posts: 360

Well we opted to run a 270 profile cam to keep it pretty driveable everyday but I was just worried about spending all this Â£Â£Â£ and then finding out that the combination of box filter and trumpet size was actually making it worse. I think the box will also cut down the TB Induction roar a little aswell.

Thanks Chris & BBR - I'll post some pics when everything arrives and starts to go on but I can't get her mapped until the 7th of April so she won't be running again until Donny.

Retroholic Joined: 23 Dec 2005 Posts: 3315

pics please i got some in a file of the last 1's of your 19 i'de love some more Smile

Level 5 User Joined: 18 Jun 2004 Posts: 114

bbracer16valver";p="83739 wrote:

sorry i cant make that one bigger but it spat back a flame and caught fire

I only use ITG, their foam is non flammable, and you will only catch a filter on fire from a spitback if standoff has saturated the filter itself in fuel.

Level 5 User Joined: 18 Jun 2004 Posts: 114

Mick, you wont be running excessive rpm, so behind the std rad i cant see you actually getting enough induction length, go for as long as you can initially.

And are you running 45mm ID trumpets into a 48mm taper body?

Why dont you just run the taper trumpets?

Oh, and in my custom rad cases, the trumpet and filter extends infront of the rad over the top, so there are no problems with induction temps at all.

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

he meanss 45mm in length, hes goign into an airbox with a long snorkel so that makes up induction length as well benny boy

Level 5 User Joined: 18 Jun 2004 Posts: 114

I know, but chambered harmonics are a totally different thing, all my plenhams are designed to cancel secondary reflected waves outside of the original refraction.

I'd run long trumpets, or spend alot of time playing with your filter hose length and airbox volume.

Retroholic Joined: 12 Feb 2004 Posts: 5685

BenR";p="83844 wrote:

cancel secondary reflected waves outside of the original refraction.

[fade:667dc31624]WHOOSH[/fade:667dc31624] Laughing

Site Subscriber Joined: 28 Jan 2005 Posts: 3547

BenR";p="83844 wrote:

I'd spend alot of time playing with your hose length

Ooerr missus

Embarassed

sorry!

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

Well I assumed he was gonna use a big airbox anyway thus the short 45mm trumpets on the TB's to allow for room between the bellmouths and the front wall to prevent ill timed reflected waves.

if its to close I can see it running very rich at low rpms!

ben lets be honest if we were doing it we'd do it properly!

Level 5 User Joined: 18 Jun 2004 Posts: 114

nah, if i were doing it i'd throw some socks over some silicone hose and run it on the std ECU with an adj pressure reg.

Retroholic Joined: 12 Feb 2004 Posts: 5685

In violation of my patent i might add!

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

best one I remember was a volvo 740 or whatever it was auto, carb off, fuel pipe stuck into the inlet manfiold. carb was being rebuilt.

In forgot about lack of carb and the fact it would start in drive, started it, woohoo! lots of air and lots of fuel!

About half a mile per gallon!