Intercooler pipework size...

[Mr Whippy]

What is the best size to use.

I've read a bit in "Maximum Boost" by Corky Bell about keeping velocity down, but then heard higher velocity is good for response, as well as using a slightly larger post intercooler pipe size than the pre intercooler size.

Just for a diesel 306 (well two), intercoolers are 3" i/o, turbo's are 1.75" outlet, and the manifold intake is 2.3"

Tempted to go then for 2" for the first half > 3" into the cooler, and then 3" down to 2.25" for the second half, with a small bump up with silicone to the manifold intake.

Will all be mandrel bent stainless steel welded sections, and the odd samco for a bit of flex or join to turbo/intercooler etc.



Just not sure if there is any point in going bigger than 2" for the second half. The cars are running small GT15/K03's running to ~ 150-160bhp at 4000rpm.

The book above is pretty good but it reads as if even 2" might be theoretically overkill for my application already.


Just wanting to do the best thing really, rather than just use bigger pipes because they look better

Dave

[stevieturbo]

2" pipe is handy to get....that would do it for me.

[GavinPearson]

If you are mandrel bending then 2" is plenty.

I would have the tubes expanded where the hose clamp goes to try to stop high boost hose blow-off.

[Mr Whippy]

Yeah, we will just be buying loads of 2" stainless bits then welding them in, so it'll all be nice mandrel bends etc...

But yes, having a lip on the end of the parts we make is a good plan... I've seen alot of people just use high-strength Mikalor type clips, wheras I think even for 1.4bar boost a good jubilee clip should be ample with a lip to push up to...

Just finding somewhere to do that though. Unfortunately our brake pipe flaring tool is a tad too small for 2" stainless


Now, whats the best stainless to go for if your doing alot of welding? Any recommendations on spec, or what to avoid? (have no idea when it comes to stainless etc)

Dave

[Howitzer]

When I was on the test rigs there was little difference with pipe length etc when making up different set ups.

You MUST put a swage on the end of the pipes though for the clips to sit behind, easy enough to do.

Dave!

[stevieturbo]

Unless using over 15-20psi, I wouldnt be overly concerned about beaded pipes. Just use good quality clips. Especially since its a diesel, and you wont get any massive spikes of boost when closing the throttle etc.

Easiest option if you are welding the pipes together, is to stick a small bead of weld on the end to prevent pipes slipping off.

[Mave]

Mr Whippy said:

Yeah, we will just be buying loads of 2" stainless bits then welding them in, so it'll all be nice mandrel bends etc...

But yes, having a lip on the end of the parts we make is a good plan... I've seen alot of people just use high-strength Mikalor type clips, wheras I think even for 1.4bar boost a good jubilee clip should be ample with a lip to push up to...

Just finding somewhere to do that though. Unfortunately our brake pipe flaring tool is a tad too small for 2" stainless


Now, whats the best stainless to go for if your doing alot of welding? Any recommendations on spec, or what to avoid? (have no idea when it comes to stainless etc)

Dave

Ideally, you want "L" grades (eg 304L, 316L). 304L is probably easier to get hold of (and cheaper). If you get the standard grades, it will be as easy to weld, but suffer corrosion fairly quickly

[Mr Whippy]

Ah all sound advice, thanks.

Yep, thought of running a weld bead at the end of the pipe just to give the clips something to run up against... we are running about 22psi.

I have a few friends with the same car running no beading but they opt for heavy duty Mikalor type clips, but I'd prefer to save money and use good jubilee's and have a bead!

Dave

[Greendubber]

Mr Whippy said:

Ah all sound advice, thanks.

Yep, thought of running a weld bead at the end of the pipe just to give the clips something to run up against... we are running about 22psi.

I have a few friends with the same car running no beading but they opt for heavy duty Mikalor type clips, but I'd prefer to save money and use good jubilee's and have a bead!

Dave

I've welded a bead onto pipework to stop hoses blowing off under boost, it worked a treat!.

[stevieturbo]

Mikalor are crap. The bands at the split section are too thick, causing them not to seal very well.

[chuntington101]

are you plsnning on useing stainless for the boost pipes?? dont most people go for aluminium??

cheers

Chris.

PS. is this still a top or are you going for a FMIC??

[Mr Whippy]

Ally just seems less strong, a friend used easyweld and although his welds were not perfect they snapped/opened up (probably due to lack of decent movement afforded by silicone connections?)

Stainless for us is easy to weld with the mig and the right wire, it looks nice and shiny, and it's no doubt stronger.


Gone for a front mounted setup now. Copying my friends setup basically, got the intercooler bought and all that.

Got everything else sorted, just need to get this put in and upload my latest revision of the mapping I've been working on

150bhp and 255lbft is the initial target, but pushing a little just to find the limits is the next step. Need to buy an AFR and EGT sensor/gauge and some oil temp monitoring gear.

Dave

[Mr Whippy]

Pics from friends





Pretty big, fits about perfectly for our application, there may be better coolers out there but for ~ £110 it's spot on for what it is. Performance seems acceptable but being sad I want to get a differential pressure gauge and measure the pressure drop and temp drops

Dave

[stevieturbo]

From what I understand of diesels. And AFR gauge is pointless.

Its all about EGT.

[Mr Whippy]

Yeah, well I have some nice diagnostics stuff right now already, just wanting more as I'll be pushing quite hard with the turbo (both ends)

Why do you see diesel AFR as not much use, because smoke is a more significant indicator?

Dave

[stevieturbo]

excessive smoke is bad....thats as much as I know.

AFR's vary too much, and dont really mean anything due to its lean burn nature.

However, if the EGT's get too high, meltdown will occur. High EGT's bare little resemblance to AFR's though.

In fact, the leaner it is, the cooler the EGT's seem to be. Quite the opposite for petrol.

So going by that, too much fuel could cause meltdown, as opposed to too little ( as they always run lean )

So EGT is the way to monitor things.

[Mr Whippy]

Right, might not bother worrying about wideband EFR then, and just watch smoke and temps mainly...

Can you recommend a good EGT gauge at all? Would like something that maybe comes with software or can run with software so I can log the data, since I'm logging lots through OBD and PCMScan already, and it'd be nice to have it all tally up in Excel afterwards

Dave

[stevieturbo]

Mr Whippy said:

Right, might not bother worrying about wideband EFR then, and just watch smoke and temps mainly...

Can you recommend a good EGT gauge at all? Would like something that maybe comes with software or can run with software so I can log the data, since I'm logging lots through OBD and PCMScan already, and it'd be nice to have it all tally up in Excel afterwards

Dave

Contact Bill Shurvinton for an Innovate TC-4.

It can log up to 4 K-type thermocouples via laptop ( as well as daisychain with any of the other Innovate devices )

[chuntington101]

looks like a decent intercooler for the money there Dave. just one question mate. the end tank where in inlet and outlet pipe attach, is there a divied bettween the hot air coming in and the cold oing out?? its hard to see from the pics.

cheers

chris.

[Mr Whippy]

Haha, yeah, I've not seen the intercooler yet, my brother has the pair (one for a 405 Mi16 > 1.9Td conversion and trying to get 140-150bhp )

However, he did note the same concern, so had a look inside. There is a plate in there, welded to the end-tank body, but because of the odd number of tubes one side has one more than the other apparently, and the seal to the intercooler end plate isn't welded, but it's a pushed up tight fit.
Soooo, we are tempted to put the thicker core first (hot side), and into the air flow, and the thinner side up further behind the bumper (not sure if thats the ideal way around but as the air shrinks as it cools it makes sense)

I'm not sure what the pressure issue might be with the non-welded join, I'm sure it's not a massive issue though, got to be easier for air to go down and round than wait and try get through a tiny gap



Thanks for the link Stevieturbo, those EGT parts look like a damn good price. So whats the best plan for those? I've heard pre and post turbo is a good plan as you can see the heat the turbo is taking in and when it reaches that limit of not letting more heat out and just absorbing it... Can probably stuff a probe in where the EGR normally is, and then have another in the downpipe...

Will take a few more pics of the cooler this weekend, in detail around the intake end tank, for anyone who is interested

Dave

Edited by Mr Whippy on Friday 18th April 09:33