boost plumbling sizes

[suske]

Hey everyone

I thought this mught be a good topic to dicuss, on a standard turbo what would be the pipe size's one could push it to from turbo to ic, from ic to throttle, and even for upgraded turbos....

What would be the negative affect of to big and to small...

[aep886]

2.5" hot pipe
3" cold pipe

[phoenix s14]

Bigger piping = more lag due to larger volume to fill
smaller piping = quicker response but could get choked if you are running large amounts of boost especially on bigger motors.

typically you could run 50mm boost pipes on a CA18 but on a RB25/6 it will be small and you could have boost drop or fade away.

[POWDER]

Phoenix S14 is Right.....

If were talking standard to slightly upgraded turbo's the following would apply as a good base for keeping lag down and boost smooth

CA18DET - 40 to 50mm piping from turbo to intake
SR20DET - 50 to 60mm piping from turbo to intake
RB25DET - 60 to 70mm piping from turbo to intake

*** Sizes are approximate***

Please note though that you should keep the throttle body side of the pipe the same size as the intake itself with a smooth reduction to avoid vortexing on the intake. About a 10 to 15cm section should do fine.....

You should also try keep the pipes as short as possible to reduce lag as much as possible

The smaller sizes above will give you less lag and the bigger sizes will allow higher boost (or should I say more reliable air flow), all depending on what you want out of your car.

For very large turbo upgrades I would suggest the following sizes though

CA18DET - 50 to 60mm
SR20DET - 60 to 70mm
RB25DET - 70 to 80mm

These sizes though are respective to your intent for the car and turbo size, in all cases keep the pipes as short as possible.....

My car for instance I am running an SR20DET with 50mm boost pipes all the way through and have tried to make them as short as possible... It's given me very linear power with close to no lag at all and my boost stays up to all the time on the standard T25.... Soon upgrading to a T3/T4 and will keep pipes at 50mm to ensure as little lag as possible

Please note the above info is also up for some correction if anyone cares to goi an opinion....
Hope this helps....

[200sxrb25]

And inter coolers?

[POWDER]

Inter-coolers generally add more lag the larger you go, obviously the larger the intake and output, the less restriction it will cause, but the larger you go, the more it will cool or can cool, but remember, the larger, the more lag you will have

My intercooler on my SR is a 600 X 350 X 50 +/- and has 50mm input and outlet to match my boost pipes....

With an inter-cooler though, it really does all depend on how much power you are or do want to run..... But they are generally rated towards power figures so just ask the tuner shop what size intercooler would be sufficient for your requirements.

My choices were all made based on that I want very linear power for drifting, SR is also known for running hot so I went for a slightly larger inter-cooler to reduce as much air temp as possible too.

For normal road use you shouldnt need anything bigger than half my intercooler size on a CA, but if you want to do drags or drifting, one my coolers size would be about right, possibly even bigger depending on how serious you want to get.

But remember as well, it doesnt matter how large your intercooler is if it is sucking in hot air, it will obviously help, but a small intercooler with a cold air intake would possibly be twice as effective anyway than pulling in hot air from the engine bay directly.

Also once again, this is up for correction and further details I may have missed out if someone wants to add to it...

[POWDER]

And inter coolers?

@ 200sxrb25 : P.S. For an RB I would actually just not care about small intercoolers, I would only look at how I could make it fit in.... lol , RB's do run pretty hot, also bonnet spacers help spans too for the cooling.. and help demist windows in the mornings, lol

[Grant222]

suske, did you come right with the blow off valve story?

[POWDER]

suske, did you come right with the blow off valve story?

What BOV story ? Sounds interesting....

[Grant222]

the bov was open at idle and causing car to die, I think the spring was to soft, Andre could suck it open manualy, it should not be that easy to open

[POWDER]

Definately not, what BOV was it? Also you can probably use a couple of washers to stiffen it up, or get another spring, actually I might have one depending on the BOV type......

A spring should esentially be rated to about 70% of your boost sothat when equalised it will stay closed, and then when in vacume it will only open when on 30 to 50% boost. The whole accent being on the Silent but Violent when it needs to be ..... Will also keep some boost in sothat you dont have to fully re pressurise all over again. This will also give you some turbo flutter on low boost, but still within safe range, only slow down flutter and not reverse flutter, but when in full boost will not give any flutter and only Blow Off sound.

[Grant222]

that is exactly how mine is setup

[POWDER]

that is exactly how mine is setup

Nice man, ye I set my Tial up like that too, had to cut 1 1/2 rings off a frigging hard spring with a grinder to get there, lol..... Just need to get rid of my boost leak now for it to work effectively like it should, ha ha. But u can ask Nate n BG, sounding prity well even with boost leak....

[Grant222]

how do you know there Is boost leak? can you hear it or have you found the leak already?

[POWDER]

Manifold leaking before turbo, not boosting and can hear the puf puf puf puf puf BIGTIME..... Just looking for new Zorst mani at the moment though and when have it then putting on my copper gaskets......

U dont possibly know where I am going to find a top mount mani with 38mm external wastegate port do you? Not having to move the ABS pump will be a bonus.... ha ha ha..... it's a blacktop rwd from S14a (Non VVT) jap import motor.....