intake runner lenght with ITBs discussion

[Bean]

Hi,

can anyone with a T3 intake adapter for the 20V ITBs measure the lenght of the runner (face to face)? I'm trying to get my head around some runnerlenght calculations

lenght of the bigport head from valve head to face is ~80mm if anyone else is interested
lenght of the ITBs (AE101) are 75mm
so this is ~154mm + the adapter + stacks for the endresult.

Cheers Bean

[Bean]

just received the info from T3 - the adapter is 75mm

so this is 80 (intake on head) + 75 (adapter) + 75 ITB = 230 + stacks

with the T3 Stacks this will be just over 305mm but I think I'll get the Jubiride 90mm ones to get it up to ~320mm and hope for good VE around the peak torque area

[Bean]

did some calcs with this http://www.exx.se/techinfo/runners/runners.html
and came up with the following results (assuming stock engine and 268° cams at 0.1mm lift - catcams.com 710514:

VE enhancement at the following RPMs

T3 setup (75mm stacks): 5584
Jubiride setup (90mm stacks): 5321
velocity of sound setup 1 (102mm stacks): 5129
velocity of sound setup 2 (120mm stacks): 4863

any oppinions?

[jondee86]

For my ITB install I will be around 340 mm from valve to end of stack.
My manifold is longer than the T3 adapter, and to avoid the stack hitting
the brake booster (RHD car), I have had to make some curved stacks

The engine is not running yet, but I am hoping to achieve a solid bottom
end with a nice flat torque curve. ST ITB's on a 16V smallport. Should
have something to report by the end of the month

Cheers... jondee86

[Bean]

jondee86 Wrote:For my ITB install I will be around 340 mm from valve to end of stack.
My manifold is longer than the T3 adapter, and to avoid the stack hitting
the brake booster (RHD car), I have had to make some curved stacks

The engine is not running yet, but I am hoping to achieve a solid bottom
end with a nice flat torque curve. ST ITB's on a 16V smallport. Should
have something to report by the end of the month

Cheers... jondee86

interesting that'll be an inbetween the two velocity of sound setups - keep us posted

[oldeskewltoy]

So far I'm still running with a single T/B.... but I'm beginning to lean toward multiples....


I've got a friend with another adapter(pre-production piece) and he is setting up for multiples. Take a close look, besides the adapter, there is a 12mm thick piece of birch plywood to use as a temp barrier, as well as space the intake further.....

Quote:I've done some calculations for intake runners, .......................

Here is his thread..... http://dirtydrifters.freeforums.org/work...5-108.html

[Bean]

can't look at the thread as I'm not registered member... but by the looks of it he uses the T3 stacks so 75mm so that'll be a total of 317mm incl. the plywood so similar to my intended setup with the 90mm stacks.

if my calculations are close to the endeffect this should boost peak torque as I'll be expecting peak torque around that area with my future cams...

insulating the runners from the heat of the head sounds like a good idea although I'm not sure if it has a great effect - especially running open stacks... but it's an easy test so I'll keep that in mind especialy as I'll be running an airbox to have a nice fresh air supply (and a bit more length as well)

if all goes well I'll be able to supply more info mid to late summer still trying to source some more money to build a fresh bottomend to go allong with the spare head but that's way into the future especialy if I want to make some progress with my other project too...

[Jimmi The Kid]

Does anyone know if plywood are gasoline prof? I will place my injectors at the end of the stack - oldschool formula 1 trick...

[Jimmi The Kid]

Does anyone know if plywood are gasoline prof? I will place my injectors at the end of the stack - oldschool formula 1 trick...

[jondee86]

Jimmi The Kid Wrote:Does anyone know if plywood are gasoline proof?

The more usual materials for thermal insulators are "Phenolic" sheet (a
fabric reinforced plastic similar to Tufnol) and the more expensive, but
better performing "Teflon" sheet (virgin PTFE). I have an insulator water
jet cut from 3.1 mm Teflon, but the engine has not run yet, so I cannot
comment on the performance.

Plywood will certainly be a good thermal barrier. The glue in marine ply
is waterproof, but probably not gasoline proof. I think that the effects of
heat, humidity and pressure, would cause the plywood to change shape.
So you should regular check the manifold bolts to make sure the clamping
is good

Cheers... jondee86