turbo build boost pipes

27th November 2011, 15:30

what kind of boost would you manage to run using 2.25" pipe work?

i have a reducer 2.5"-2.25" coming from the TB and the intercooler i have been looking at is 2.25" inlet and outlet would this be ok or would i be better off looking at a full 2.5" kit so theres no reducers anywhere

27th November 2011, 22:31

It will be fine with reducers, just don't go plumbing in different diameter pipes. And keep bends to a minimum if you can.

I'm ripping my 2.25 pipe work out and replacing with a full set of 2.5 as I plan to run more boost, maybe even a bar, so restriction is going to be down no end.

It's a tad more expensive but does look chunkier and better in the bay.

27th November 2011, 22:55

thats not a good idea^^^

i run 2" boost pipes and my car will be good for 300@wheels

27th November 2011, 23:41

It's a common misconception to put massive boost pipes when upping the boost (to a point) it's the overall volume of the pipes that matter. Increasing the diameter of the pipes will only cause lag because there is less air density/ boost in the pipes. 2.25 will be more than big enough for any saxo engine spec.

28th November 2011, 01:04

2.25 on mine when it was 400hp. Pointless going bigger. Harder to route, more expensive, laggier. Small is beautiful as my wife says...

28th November 2011, 01:38

Just checked some spare pipe I'm running 2 inch

could of sworn it was 2.25 but that's what I'm doing replacing with 2.25.

28th November 2011, 02:19

what power are you running mate? if you increase the diamiter try re-routing the pipes so there shorted so you dont get more lag if thats posible to do with the room in the bay

28th November 2011, 02:38

Hoping to run around 13 psi to start with mate, I'm only replacing because of a different theme I'm going for aswell as needing to re route boost pipe as they aren't in the ideal places. I prefer the look of 2.25 pipe so just a personal preference.

28th November 2011, 05:48

Your making the car fast not tarting it up!

If your trying to make a good setup, common sense would suggest you go for the smallest ID pipe necessary for the desired output.
And 2" boost pipe is efficient upto 360hp

28th November 2011, 09:49

aggree with danny, i bought 2.25 before i down spec'd, ill be goin 2 in the new year

28th November 2011, 10:28

what size is the outlet from the turbo?
,that tells you what size to use
you have enough lag on a turbo without making it worseby giving it more volume to fill up

28th November 2011, 11:25

Hmmm i have no choice now, otherwise I think your gunna kick my arse Danny

28th November 2011, 14:59

Like John said, even most gt30's use a 2" outlet off the turbo.

Thats right steve

28th November 2011, 18:45

i use 2 inch pipes and have no issue with power

Si

28th November 2011, 18:47

Quote:

Originally Posted by toger13

i use 2 inch pipes and have no issue with power

Si

get a progress thread up si, your cars awesome!

28th November 2011, 19:41

my T34 has a 2 inch outlet and my cooler has 2'' inlet and outlets, ive just swapped all my pipes to 2''

28th November 2011, 19:58

Well I am thinking of starting with low boost and upgrading to go higher boost... I see 9/10 people use 2.25" so think I may go for that?

Was looking at gt2871r turbo but with low boost then maybe turn it up or upgrade to a gt30

Cheers for comments guys... Didn't mean to cause a boost war

LOL

28th November 2011, 20:01

Quote:

Originally Posted by Pug106-GTI

Well I am thinking of starting with low boost and upgrading to go higher boost... I see 9/10 people use 2.25" so think I may go for that?

Was looking at gt2871r turbo but with low boost then maybe turn it up or upgrade to a gt30

Cheers for comments guys... Didn't mean to cause a boost war

LOL

by saying that you havnt taken onboard several peoples opinion, also a few people have very good knowledge. please dont overlook this.

2" pipe only becomes restrictive over 360hp, are you going for more than this?

my guess (not being mardy) is you havnt been in a saxo/106 with a good charged setup?

also, i would totally advise againt a gt2871r. but thats just me.

what is the car for?

28th November 2011, 20:08

Car is going to be used for daily driving aswell as the odd track day

What would you advise against it mate?

And haven't been in charged 106/saxo at all! Lol

Not got a power that I am aiming for just gone through the thread again and realised that a lot of people would prefer the 2" setup but I'm finding it hard to find a intercooler with 2" inlet and outlets lol

Also does anyone know that size the cituning pipe is? The one that comes off the TB

28th November 2011, 20:13

Quote:

Originally Posted by Pug106-GTI

Car is going to be used for daily driving aswell as the odd track day

What would you advise against it mate?

And haven't been in charged 106/saxo at all! Lol

Not got a power that I am aiming for just gone through the thread again and realised that a lot of people would prefer the 2" setup but I'm finding it hard to find a intercooler with 2" inlet and outlets lol

Also does anyone know that size the cituning pipe is? The one that comes off the TB

the turbo wont start spooling til late 4k on a good setup...wont make full boost (say a bar) till well past 5k. this gives you a very short power band which is the opposite thing than you want.

for a road car id bet money that a properly sorted/spec'd car with a gt25 would piss on a car with a gt2871r or even gt30xxx.. on the road.

on track its different, but even then i doubt there would be 'that' much in it.

id find one with 2" outlets, the end result will be worth it.
when building a car like this, think of the end product you want then design/choose everything with that in mind.

28th November 2011, 20:25

what is a good gt25 turbo mate?

will have a browse now and see what I can find lol

28th November 2011, 20:27

just search garret gt25r

28th November 2011, 20:29

would it be ok if i used a intercooler with 2.25" inlet and outlet but all 2" pipework from inlet to the intercooler and turbo to the intercooler? so it only has reducers on the intercooler inlet and outlet?

28th November 2011, 20:30

you can do, as thats what ive had to do, not ideal though.

28th November 2011, 20:34

yeah i can only find intercoolers with 2.25" smallest inlet and outlet lol

what turbo you running? and what sort of rev does it spool n kick at?

28th November 2011, 20:38

you can get them with 2" ends. just have to look harder. also, you could have one made.

im using an unusual turbo, its a td05h big 16g but with a t25 exhaust housing and larger exhaust wheel.

my car starts making boost under 3k and is on full boost by around 4k'ish.

28th November 2011, 21:26

Danny has pretty much wrapped this up for you really - a gt25x (of some sort) or even gt2860 is all you'll need max for a road car. I'd avoid the 2871 completely unless you've really got a very specific goal in mind and have carefully considered your powerband. It's quite mismatched for the engine, especially for a road car

As I think Danny mentioned earlier - pick a setup you want NOW, then aim towards it. Try to avoid buying something twice - ie, buy the correct intercooler now, use it again when you upgrade etc

Oh and Rob - I frequent Kent meets er... frequently. When my car is built up again (March time ish) if you've still not been in a boosted car by then, you're welcome to come out in mine.

28th November 2011, 21:33

Quote:

Originally Posted by RossDagley

Danny has pretty much wrapped this up for you really - a gt25x (of some sort) or even gt2860 is all you'll need max for a road car. I'd avoid the 2871 completely unless you've really got a very specific goal in mind and have carefully considered your powerband. It's quite mismatched for the engine, especially for a road car

As I think Danny mentioned earlier - pick a setup you want NOW, then aim towards it. Try to avoid buying something twice - ie, buy the correct intercooler now, use it again when you upgrade etc

Oh and Rob - I frequent Kent meets er... frequently. When my car is built up again (March time ish) if you've still not been in a boosted car by then, you're welcome to come out in mine.

All ok mate nice 1

well I would like to aim for 15psi or maybe more... Which is why I was going to go for 2.25" but now I'm not sure to go for 2" or 2.25" lol

Looking at getting a 16v head and block and building it up untill fully built then just swap it into the gti

28th November 2011, 21:35

You reckon I should use a gt25? My current turbo is to small.

What car uses gt25? Not looking for a brand new one.

28th November 2011, 21:37

the boost pressure you run wont make a blind bit of difference to pipe size. you could run 100psi on 1" boost pipe if you want.

boost is due to restriction through the engine. what air doesnt make it through the engine then creates posotive pressure in the inlet side of the system. when the engine can swallow over 360bhp worth of air,,, then you will need to up things like intercooler size/boost pipe/throttle body etc.

28th November 2011, 21:38

Quote:

Originally Posted by stevo1600

You reckon I should use a gt25? My current turbo is to small.

What car uses gt25? Not looking for a brand new one.

nissan 200sx s13

29th November 2011, 01:31

the 200sx is the best one when i get my boost started i'm going to be using a gt25 hybrid of a fista rs turbo but will have to mod a manifold as they arnt a stranded fitment

11th October 2012, 13:19

I'm also in the process of the turbo build, I have a c2 vts engine fuller forged with je pistons etc etc,
I want to try and find some pipe work but I have no idea where to start, is there anywhere i can find a diagram to what bends etc I need or is it just trial and error,

Also I haven't seen many c2 engines turbo'd why is this .

11th October 2012, 13:48

Quote:

Originally Posted by Rhysupply

I'm also in the process of the turbo build, I have a c2 vts engine fuller forged with je pistons etc etc,
I want to try and find some pipe work but I have no idea where to start, is there anywhere i can find a diagram to what bends etc I need or is it just trial and error,

Also I haven't seen many c2 engines turbo'd why is this .

pipework is specific to your own car, and the layout of your setup. So many variables that it's almost impossible to give advice or a diagram.

Have a look through some build threads to see how others have done theirs is really the best idea.

I run a C2 engine in mine.

11th October 2012, 14:27

Cheers mate I will do, is there any reason why atspeed use the vts/gti engine over the newer c2 engine?
Could you post some pics of your engine bay up please.

11th October 2012, 14:49

Quote:

Originally Posted by Rhysupply

Cheers mate I will do, is there any reason why atspeed use the vts/gti engine over the newer c2 engine?
Could you post some pics of your engine bay up please.

11th October 2012, 15:21

That is one sorted car! Looks mint mate.
Isn't that the vts/gti rocker covers tho.

11th October 2012, 15:36

The rocker covers are interchangeable from the j4 to jp4 mate

What radiator is that Ross, and do you need to modify the slam panel to make it fit to the outside?

Btw that engine bay is mint as f**k

11th October 2012, 15:37

Is there any reason why swap them over ? As I thought the c2 ones didnt leak as much as the others.

11th October 2012, 15:46

yes they are gti/vts covers, swapped onto the JP4 head. Biggest reasons for using them is the very high exhaust temps don't get along with the plastic covers (although some people have got away with it, why risk it...) and more importantly, you can easily adapt the J4 covers for AN10 breather fittings, something not easily possible on the JP4 covers.

That radiator is a pro-alloy rad. Circa £600, or around £1100 with the intercooler. No real modification needed, just brackets made up to hang it out the front. You need bottom brackets to support the weight though:

11th October 2012, 15:51

Aaah thats why!! I'll keep that In mind and change them over cheers mate

11th October 2012, 15:53

Quote:

Originally Posted by Rhysupply

Aaah thats why!! I'll keep that In mind and change them over cheers mate

You don't have to use them - I didn't on my 2010 spec (300bhp).

Personal preference is all

11th October 2012, 16:59

Its not worth the risk as you said,did you do all the work yourself?

11th October 2012, 17:30

Quote:

Originally Posted by Rhysupply

Its not worth the risk as you said,did you do all the work yourself?

Titch (my friend) did that pipework but it's straightforward

Take your time, mark it out and think it through. Write it down as you go. Start at one end.

"So, I need a 30 degree 78mm to 65mm reducer on the TB, then 340mm straight pipe, then a 90 bend there, then a 180mm straight there to intercooler... etc" (whatever your spec is etc...)

11th October 2012, 20:15

Quote:

Originally Posted by Ross

That radiator is a pro-alloy rad. Circa £600, or around £1100 with the intercooler. No real modification needed, just brackets made up to hang it out the front. You need bottom brackets to support the weight though:

Don't suppose you'd know if they made a cheap-o version of that rad at all, so basically one that you can mount to the outside of the slam panel without having to cut a great chunk out of it to make it sit right, but without such a whopping price tag lol, even if it doesn't have the cooling efficiencies a pro ally rad does?

Hope that kind of made sense