Rowans GPX Turbo Build

[Rob Furniss]

Not much to update on at the moment but I thought i'd go for it anyway.
He's waiting on lots of little sh*tty parts arriving - AN fittings for the turbo, silicone hoses etc.

Turbo cover has arrived and is on.
He's wrapped most of the up pipe.
Most of the IC pipework is done.
Sump is tapped for the return and has a fitting in ready for the braided hose (waiting on).
BOV was a pita to fit due to the circlip and us having circlip pliers which were too small, on a sunday, after everywhere had shut.


Got a Walbro 255lph pump to fit when that arrives (got one for mine at the same time too) which i'm not looking forward to fitting based on the last one I did, hoping that was a one-off and this will be easier.
Still not convinced about his up pipe location, think it's way to close to the stepper motor and will melt it but we'll see. If that goes pear shaped might have to remove the stepper and make something up to blank it off.

Other than that all good

[Rob Furniss]

He went for the first start today - engine turned over a couple of times but wouldn't fire up, not hearing anything from the new fuel pump.
Then the battery died so it's on charge now.

[bjk]

The joys of custom builds, eh?

[Rob Furniss]

Started just now, didn't need much of a charge.
Well it ran and didn't stall, he left the air filter off the turbo so we could see stuff moving, didn't spin up till about 3500 I think.
Boost gauge wasn't registering anything except negative / vac, not sure why yet unless his wastegate isn't plumbed in right or something.

Not ready for the first drive yet but it's progress.

[Technikhaus]

If it's anything like my legacy, it won't boost until under load, as there not enough exhaust gasses to create any boost

[Rob Furniss]

If it's anything like my legacy, it won't boost until under load, as there not enough exhaust gasses to create any boost

Ah ok, so it's unlikely to boost just on the drive, that's fair enough.
I did warn him about the size of the turbo as it's pretty big, he's got a smaller one in the garage (but he won't want to go smaller) and he's got another on the way which is supposed to spool quicker (by precision turbos 6765), should be delivered today so he's got options.

[Rob Furniss]

Crappy cheap AN fitting for the turbo oil feed is pissing oil out all over from it's swivel not from where it's attached to the turbo or hose, think he's going to order a speedflow one to replace it (or whack a barb on and some normal hose, have found he braided stainless stuff to be a pain).
EDIT:looks like he just hadn't tightened it up.

[Rob Furniss]

If it's still taking time to get on boost maybe we will add a small supercharger to help get it spooled up quicker, possibly a little Eaton unit off a mini cooper...

Pain in the arse plumbing - yes
Hard to tune - maybe
Overkill - absolutely

Reason to do it then?
Cause we like things that make noise.


I think he should have some cams here from RPW in a few weeks too.

[bjk]

Did he really fork out for the cams from RPW? What did they set him back?

[Rob Furniss]

Cams are on order yes, not sure of the price but about 2K isn't it? they are the turbo ones - the HKS 272 profile and I understand the benefit due to them overcoming the overlap issue where you lose boost down the exhaust valve if you don't fit them. (if it's true - which I have no reason to believe it's not)

I didn't run them before and got to about 250/260bhp at the fly (Tiptronic) on 7 pounds of boost but I was always down on boost compared to what my calculations were suggesting, Steve Johnson in the UK had the same issue too so we both ended up with getting smaller and smaller pulleys on the supercharger to compensate and therefore maybe over-running the chargers more than they needed.
On mine this time I will get some dyno runs in before and after cams to prove what the difference is but with the same pulley size, I would expect to see more HP and more boost which would prove the theory that boost gets dumped down the hole without the turbo cams.
I also want to then fit a Sprintex 210 supercharger as apart from one small change to the design of the intake it's a direct swap and more efficient.


Has there been some discussion on here about whether or not they are worth it? (missed it if there was)

For Rowan - he just wants cams no matter what - even if he loses power, he even said he really would like them to be lumpy, I said even if you lose driveability and power? he just wants the sound I think. (He used to have a Maloo R8)
Rowan is also going forged internals at some stage but I don't want to be involved in that, in fact I want my car back (his is on the drive getting this treatment and he's using mine for work meaning I can't work on my SC project except in Autocad or for short periods, that intake plenum has been on and off more than I care to tell)

[bjk]

Yeah about 2k. One other member has used them in an N/A application, but various other issues were at play so it wasn't quite conclusive how much outright benefit there was. He was happy with the performance though, 4 speed tip too. If they were less expensive more people might go for them, but at over 2 grand before even installing them, it's a bit steep.

[Rob Furniss]

Yeah about 2k. One other member has used them in an N/A application, but various other issues were at play so it wasn't quite conclusive how much outright benefit there was. He was happy with the performance though, 4 speed tip too. If they were less expensive more people might go for them, but at over 2 grand before even installing them, it's a bit steep.

Yes it's a fair bit of wonga, we will tackle the cam swap so no extra cost there but I don't fancy doing the pistons at all - told him he better budget for an engine builders when he gets that far.

[bjk]

Yeah about 2k. One other member has used them in an N/A application, but various other issues were at play so it wasn't quite conclusive how much outright benefit there was. He was happy with the performance though, 4 speed tip too. If they were less expensive more people might go for them, but at over 2 grand before even installing them, it's a bit steep.

Yes it's a fair bit of wonga, we will tackle the cam swap so no extra cost there but I don't fancy doing the pistons at all - told him he better budget for an engine builders when he gets that far.

He seems quite content to throw wads of cash at it, so I'm sure he won't mind. we'll be interested to see the results nonetheless. I don't remember whether FTO007's cams came from RPW as well, but he was also using something custom on his build. Great deal of money spent on that one too.

[Rob Furniss]

He's had a short drive - turbo is spinning (I've seen this on the drive without air filter on) but it's not making boost at all.
Wastegate issue? (it's an external with a 7psi spring in apparently) we're not sure how it's supposed to be plumbed in really and has two vac lines to the top (one is completely open nothing screwed into it).
Also has another vac port on the body, again nothing in this so open to atmosphere and we're not sure how they are supposed to be, going to do some google work.
EDIT: ok that didn't take long looking on google, looks like we ran a vac/boost pipe from the turbo to the wastegate vent not the wastegate vac/boost input port, will change it tomorrow and give it a try.

[bjk]

I love it how almost every time you edit your posts, you've already worked out what the issue is.

[Rob Furniss]

I love it how almost every time you edit your posts, you've already worked out what the issue is.

I know, I could just delete them and not look like an ass but i'm an honest ass.
To be honest typing things makes me think more and work stuff out.

[bjk]

I love it how almost every time you edit your posts, you've already worked out what the issue is.

I know, I could just delete them and not look like an ass but i'm an honest ass.
To be honest typing things makes me think more and work stuff out.

It's good for anyone watching from the sidelines anyway. And for record keeping, which is basically what I use my thread for lol

[Rob Furniss]

He's driven it a couple of times, we've changed some of the connections to the turbo to stop leaks oil leaks etc and now no leaks and no smoke so that's good.
But he's not got boost, his boost gauge goes from reading minus to 0 so it's working, I've also connecting a bicycle pump to it and gave it a couple of pumps and we then see positive on the gauge (although I don't know how accurate it is).
He reckons the BOV is working so i'm now not sure about his gauge, need to put the laptop in and log it in the emanage software maybe and then convert the 0-5v readings to psi (I think I have a chart somewhere) so basically see what his emanage map sensor reckons.

But i'm really suspecting the wastegate.
Now turbo people i'm hoping you know more about wastegates than me, so just because he has a 7psi spring in his wastegate made us think (before today) that he would see boost up to 7psi and then it would bleed into the exhaust.
But I've done a bit of googling and now i'm not convinced that's true and that maybe 7psi for the spring is too low and it's maybe opening up way too early? Any easy way to test?
He does have a 14psi spring - should we just throw that in and see how it goes or is there more science to it than that?

EDIT: Now thinking it's most likely due to the 7pound spring and back pressure forcing it open but will know when we switch springs tomorrow.

[Daniel2019]

Are you sure he is driving it hard enough for it to actually spool? I made that mistake when I put a bigger turbo on the Mira (had no tacho)

"The f**k is wrong here.. what did I break?" Just needed more RPM and throttle. (although I figure that one out in about 30 seconds)

Is it all plumbed up the correct way?

[Sahin]

Weld the gate hahaha kiding
Watch the go fast Brett explanation on waste gates on mcmtv2 (YouTube channel)