I need my wastegate porting - new turbo needed!

[paulous]

Hi,

As per this thread - forum.lotuselancentral.com/viewtopic.php?f=36&t=21900 , since fitting my Piper 2.25 & PCE I'm suffering boost creep. It seems the answer is to port my wastergate but I need to find somewhere that can do it for me. I'm located in Hertfordshire , near Stevenage, so ideally I want somewhere local.

Any suggestions?? Ideally I want to take it somewhere where they at least have some vague experience of doing this! I've read the link on the wiki and I can confidently say I've got no chance of being able to do it myself so definitely need to get someone else to do it . My local backstreet garage declined.

Thanks,

Paul

[Jeemy]

I would send it to CR Turbos, speak to Craig there.

[GeoffSmith]

Gerald at GST is not far away.

[paulous]

Hi,

I've found a local garage that are quite happy to remove the turbo and they have a 'metal worker' locally who they use for jobs like this. Between them they both seem very happy to do it. However they did ask if there were other options such as controlling the overboost with the ECU or boost control valve... I said not. They also asked if the wastegate flap would still cover the wastegate hole once it's ported to 20mm..... I presume it does?? Can anyone confirm?

I also notice that various posts on here talk about porting to 21mm (and I think even to 22mm in some cases) but the wiki says 20mm. Will 20mm be enough? Is there any advantage or disadvantage of going to 21mm??? The last thing I want is to have to repeat the whole thing if for some reason 20mm doesn't work!

Cheers,

Paul

[HJ2]

in My experience i would go for 21 mm.
However there are no measurements to support that, it's just my experience...

[Jeemy]

I went 21mm. Not fitted yet.

[whippit]

All they have to do is spray the washer with some white spray as a guide, i went for 21mm ish, there was still enough metal left to be covered,

be aware that lotus used a nut to fasten the turbo to the studs that wrecks the threads so you'll need new studs and nuts

[paulsmithmk]

I went for 20mm on my s2 fitted with piper down pipe and cat - all fine now. Good to meet you Saturday btw

[Enright]

All they have to do is spray the washer with some white spray as a guide, i went for 21mm ish, there was still enough metal left to be covered,

be aware that lotus used a nut to fasten the turbo to the studs that wrecks the threads so you'll need new studs and nuts

I agree with the first bit - if you use the 20mm Bosch grindstones from B&Q/Homebase then it tends to come out at about 21mm anyway, which is plenty.

And as for the 2nd bit, Whippit is right, but you don't have to take the turbo off the manifold. Once the nuts are off the manifold studs, the tension on them is released and most of them are fairly easy to access and unscrew from the side of the cylinder head.
There are a couple of exceptions to that last sentance which are absolute sods to get at, but still easier than the turbo nuts and studs.
Then the whole lot can come upwards and out. It's a shame that there's just too little room for the manifold and turbo to slide forwards off the manifold studs before the turbo hits the clamshell, but that's Lotus for you!

[HJ2]

You can easily remove the manifold studs, and then the rest of the lot in one piece (exhaust manifold, turbo, downpipe) comes out with a little fiddling without damaging anything.
You'll need an E8 Star socket ring key to extract the studs, just take the tension of the manifold nuts first with a ring spanner:-)

[Enright]

HJ's "nutshells" are better than mine - I'm a virtual windbag in comparison!

[HJ2]

But nevertheless a good one!

[ccb056]

I'm running a 21mm port, works great.

Piper PCE, 2.5", 2nd silencer.

Note, I would get boost creep on the stock chip with no overboost.
I upgraded to the Everest chip and boost jumps to 0.9 bar at 3000 RPM and no overboost.

[whippit]

[
And as for the 2nd bit, Whippit is right, but you don't have to take the turbo off the manifold. Once the nuts are off the manifold studs, the tension on them is released and most of them are fairly easy to access and unscrew from the side of the cylinder head.
There are a couple of exceptions to that last sentance which are absolute sods to get at, but still easier than the turbo nuts and studs.
Then the whole lot can come upwards and out. It's a shame that there's just too little room for the manifold and turbo to slide forwards off the manifold studs before the turbo hits the clamshell, but that's Lotus for you!

think we got crossed wire's or nuts, the turbo to down studs are the ones i was thinking of, three studs all with nuts that wreck the threads on the studs,
lotus called them a weird name , i called them a few other names when i tried to remove them, you get a reassuring crack when you undo them then you realise the nuts just sheared the threads

[Steve A]

When it comes down to what size to port, the safest bet is to find someone with as close a spec to your car is now (or you want to take it to)
and as long as their not having problems then in theory you should be ok




Maybe

[HJ2]

Why not turn it around?

Is there anyone who encountered problems with 21 mm?

[Enright]

And as for the 2nd bit, Whippit is right, but you don't have to take the turbo off the manifold. Once the nuts are off the manifold studs, the tension on them is released and most of them are fairly easy to access and unscrew from the side of the cylinder head.
There are a couple of exceptions to that last sentance which are absolute sods to get at, but still easier than the turbo nuts and studs.
Then the whole lot can come upwards and out. It's a shame that there's just too little room for the manifold and turbo to slide forwards off the manifold studs before the turbo hits the clamshell, but that's Lotus for you!

think we got crossed wire's or nuts, the turbo to down studs are the ones i was thinking of, three studs all with nuts that wreck the threads on the studs,
lotus called them a weird name , i called them a few other names when i tried to remove them, you get a reassuring crack when you undo them then you realise the nuts just sheared the threads

Oh yes, you're right Whippit - although I thought it was 4 rather than 3. And you can still get away with undoing the exhaust from the bottom of the pre-cat housing, then attack them as part of the assembly on a bench afterwards.

[HJ2]

[Steve A]

On reflection I wish I'd gone to 21mm now
20mm would probably been OK with just the modified exhaust alone,
but then I went and moved the goal posts with the down pipe

[paulous]

All they have to do is spray the washer with some white spray as a guide, i went for 21mm ish, there was still enough metal left to be covered,

Hi, please can you confirm what exactly this means? Apologies for asking!! Do you mean spray the wastegate with the flap closed (I'm sure there'll be a technical term but it looks like a flap to me) which will then leave an outline of the flap coverage area?

Paul