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SCHWARTZ
26-04-2010, 20:08
would running bigger i/c piping give any better power or would it just cause more lag? I have been looking at a 2 1/2" i/c kit but the standard r5 one is 2 1/4 " and the outlet on the turbo is 2" so is there any benifit of going over 2"?

Haz
26-04-2010, 20:14
would running bigger i/c piping give any better power or would it just cause more lag? I have been looking at a 2 1/2" i/c kit but the standard r5 one is 2 1/4 " and the outlet on the turbo is 2" so is there any benifit of going over 2"?

nope, but wouldn't cause anymore lag. engine gulps 1700cc per revoloution so at 6000 revs i's sure you wouldn't notice.
throttle is 70mm but an enlarger there would be fine.

Kenobi
26-04-2010, 20:29
would running bigger i/c piping give any better power or would it just cause more lag? I have been looking at a 2 1/2" i/c kit but the standard r5 one is 2 1/4 " and the outlet on the turbo is 2" so is there any benifit of going over 2"?

I think that a smaller intercooler piping would be better than larger.

SCHWARTZ
26-04-2010, 20:36
so if i ran a 2.5" i/c pipework with a reducer to the turbo that wouldnt be any laggier? Is the throttle body your using the standard b18ft one haz? mine dosnt seem to be that big also do you know how big the n/a 2l version is and would this give any real benifit??

Markey Mark (BD)
26-04-2010, 20:38
so if i ran a 2.5" i/c pipework with a reducer to the turbo that wouldnt be any laggier? Is the throttle body your using the standard b18ft one haz? mine dosnt seem to be that big also do you know how big the n/a 2l version is and would this give any real benifit??

How comes Kenobi?

Schwartz, no you won't notice lag with a reducer off the turbo.

SCHWARTZ
26-04-2010, 20:51
kool il do that then just thought the turbo would have to work harder to fill the pipes before any decent pressure built up.

Kenobi
26-04-2010, 20:52
How comes Kenobi?

Schwartz, no you won't notice lag with a reducer off the turbo.

Well I see that a bigger pipe run means more boost needed to fill it. Ergo drop in power untill you up boost to componsate.

think of it as trying to blow a malteser around a table with a straw then being handed a toilet roll tube to do the same job.

man thats technical for me.

Markey Mark (BD)
26-04-2010, 21:00
Well I see that a bigger pipe run means more boost needed to fill it. Ergo drop in power untill you up boost to componsate.

think of it as trying to blow a malteser around a table with a straw then being handed a toilet roll tube to do the same job.

man thats technical for me.

Yes i see your point but the rate the air flows throught the pipework 1/2" isn't going to make any difference or any you would notice. If anything the size of the intercooler compared to the size of the turbo would make more of a difference. ;)

Haz
26-04-2010, 21:02
std and 2ltr throttle are about 70mm externally, samco's are a little tight but go on. 1700 is tapered with something like 45mm butterfly, 2ltr is more like 52mm.

kind of dan, but what you describe is more like the design of an exhaust manifold with gases escaping over the exhaust turbine which is why manifold design can make difference, not quite the same for boost

Kenobi
26-04-2010, 21:07
std and 2ltr throttle are about 70mm externally, samco's are a little tight but go on. 1700 is tapered with something like 45mm butterfly, 2ltr is more like 52mm.

kind of dan, but what you describe is more like the design of an exhaust manifold with gases escaping over the exhaust turbine which is why manifold design can make difference, not quite the same for boost

OK a 1/4 of an inch in pipework over a full intercooler pipe run has to add up surely. The thinner the pipes the quicker and better the cooling?

Haz
26-04-2010, 21:24
nope, thinner the pipes if extremely smaller, the quicker the pressure build up which creates heat, the faster it passes through the pipework and intercooler and into the engine which decreases cooling.

Kenobi
26-04-2010, 21:26
nope, thinner the pipes if extremely smaller, the quicker the pressure build up which creates heat, the faster it passes through the pipework and intercooler and into the engine which decreases cooling.

Hmmm, ok.

On my colt I have 2.5 inch pipework and my friend has 2.25.

Will there seriously be no difference?

Markey Mark (BD)
26-04-2010, 21:27
Hmmm, ok.

On my colt I have 2.5 inch pipework and my friend has 2.25.

Will there seriously be no difference?

Whats the standard size of the pipes on the Colt?

Kenobi
26-04-2010, 21:33
Whats the standard size of the pipes on the Colt?

2 inch maybe 2.25

Markey Mark (BD)
26-04-2010, 21:39
2 inch maybe 2.25

To answer your own previous question then, have you noticed any lag from increasing your boost pipe size if your using 2.5"?

To be honest mate an increase of size like that won't make too much difference at all mate, i'd be more worried about pipe run more than anything aswell as cooler design.

SCHWARTZ
26-04-2010, 22:24
2.5" it is then :D

Kenobi
26-04-2010, 22:28
To answer your own previous question then, have you noticed any lag from increasing your boost pipe size if your using 2.5"?

To be honest mate an increase of size like that won't make too much difference at all mate, i'd be more worried about pipe run more than anything aswell as cooler design.

I cant answer that question as ive upped boost changed actuator remapped car.

Rob@Backyardracing
26-04-2010, 23:22
What size is your TB, if you piping is smaller = problem... take that approach to things instead ;).. Volume of IC sizes has been proven time and time again that is doesnt seem to effect spool one bit.. for me anyway...

Kenobi
27-04-2010, 07:59
What size is your TB, if you piping is smaller = problem... take that approach to things instead ;).. Volume of IC sizes has been proven time and time again that is doesnt seem to effect spool one bit.. for me anyway...

TB?

Big Jim
27-04-2010, 08:29
Got to be careful about this. Even if your pipework is the same size as your TB then the pipework will be the restriction. The friction over the length and boundary layer build up will cause a significant pressure drop, in relative terms.
The real problem is not an increase in lag, just think about the amount of air the engine is using compared to the volume of the pipework/ic, but the pressure drop you may experience through the pipework. I know you're all used to a huge drop across that bloody carb, but it really should be minimised. All that said, in the real world you prob wouldn't really notice the difference between 2-21/4-21/2...

SCHWARTZ
27-04-2010, 20:45
so the intercooler piping should be bigger than the throttle body?:confused:
also i was thinking of using a smallish front mount something like this http://cgi.ebay.co.uk/LARGE-UNIVERSAL-INTERCOOLER-63MM-2-5-PIPEWORK-KIT-/380224807351?cmd=ViewItem&pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item58872a21b7
this wouldnt cause more lag would it? is it big enough to cool the air enough at 18psi for the volvo lump??

Big Jim
28-04-2010, 08:56
Of course it should, if you want to make maximum use of your TB. Think about what it is. Its a hole which you can change the size of, to control how much air goes through it. If you've got another hole somewhere else that is smaller, then as you open the throttle plate, the smaller hole has more and more affect on the total flow.

SCHWARTZ
31-05-2010, 16:58
ok so went to the scrappy and got a 2l n/a throttle body and its 2 3/4 inches (70mm) externally and like haz said goes down to about 52mm. So im thinking 2.5inch (63.5mm) pipe work will be fine using a reducer for the turbo and an enlarger for the throttle body is the case or will the enlarger for the tb cause probs? even tho the pipe work will be bigger than the butterfly its self?

Haz
31-05-2010, 20:49
so long as the pipework is larger than the turbo outlet and smaller than the throttle its fine.

SCHWARTZ
31-05-2010, 21:09
:confused: dont know what to do now :confused: dose the pipe run need to be bigger or smaller than the throttle body? some people are saying smaller and some bigger.

Haz
03-06-2010, 01:36
really ?
turbo outlet is the smallest diameter in th run, the most restrictive bit in the pipe run. no point makin the boost hoses smaller.
throttlebody its the largest in the run, no point makin it bigger as then the throttle is the restriction, although the pipe needs to be 70mm to go onto it.
what you've suggested is fine.

philg
03-06-2010, 09:59
2.5 is going to be best then? Im in the same boat, going to buy mine once the engines in, so probably in 3 months :rolleyes:


phil