Wastegate
 

More of an idea really. I've searched here for some more information but only pictures of the outer setup are shown.
Internal wastegates are ok but external wastegates offer better boost control. So without changing the turbo what do I need to do to use an external wastegate. I realise I must fit the external wastegate and pipe it into the system but what else would I conceivably need to do?

-Learn how turbos work
-Weld up the internal gate or replace the turbine housing with one that doesn't have one

You need to let us know what type of turbo setup you currently have, plus the reason you want to go to an external wastegate (because it's better isn't a good enough answer)

your mouth is better.

Oh Zing!

:makeout:

Well I currently have a T25 for a 200SX but it isnt that causing me to ask. I am building my system at the moment but from experience I am thinking about this change.
The first Tubular BEGI kit was installed to a friends (Dean) car by my close friend (Karl) and being such a powerful setup they were very excited for the first start. Well they were getting problems with boost control from the turbo but they didnt know why. They had fitted BEGI turbo kits to many cars without any problems before and this was no different apart from the tubular manifold. They found they simply could have less than 14psi boost in the system and control it properly because of this tubular manifold. It simply flowed so well that 14psi was the lowest he could have it set to and maintain good control.
While I realise my attempt will not be as good as the BEGI kit, becasue of its tubular nature it will be very high flowing still. I do know they fixed this problem by going to an external wastegate to allow greater control but being on a budget and not having the mighty support of Karl's firm and BEGI I don't want to stuff my chance at creating something good. I would like to be able to have several settings (5,10,15psi) and do have an EBC system ready but am worried my efforts will be like a uranium lifevest. You guys are the daddys of innovation and testing for the miata world so I value your opinions.

It's possible your friends just had a 14psi internal wastegate. If that was the case, no, you would never be able to get it less then 14psi. Internal wastegates, if set up correctly, are fine for the majority of peoples needs. You can get adjustable ones from 7-16psi, and if the turbo isn't too huge, it will work great. External wastegate setups are great if you have a huge turbo, and know how to position it properly in the system. A poorly designed external wastegate setup can suck major anus too.

Or it's possible it's another BEGi car with piss-poor boost control.

Is it not the reality of tiny internal wastegates not flowing what they need to flow?

I could run 7psi to redline on my setup.

Unfortunately not. 8psi and 12psi spring included and the flow from the tubular manifold simply kicked the shit outta the wastegate from very early on. An external setup was fashioned to allow enough control because the manifold flowed so impressively. Also you should know the my friends are just mates down the road they were BEGI exclusive UK dealers and fitters and were entrusted with the first ever tubular BEGI kit for Dean. Its not some muppets doing it at all, its just testomony to Corky's awesome skills. I guess it was underestimation of the kit that caused it.

I'm just worried I will experience similar problems and you guys have helped me to believe I won't which means, ON WITH THE WELDING :D
Any further advice would be greatly welcomed though.

BEGI ports turbo wastegates for free.

My MSM has the Mazda stock IHI turbo with its notoriously small internal wastegate. I had a custom "Absurdflow" downpipe and 3" exhaust built by TurboTim @ Shore Motorsports. After that, even with no boost controller connected and the actuator arm lengthened, there was still creepage to 12-14psi and sometimes much higher than that. Now, after the porting, the car never exceeds 9.5psi when I turn off the boost controller, plus I have very consistent boost control when I do choose to go higher.

^EPIC :laugh:

I suspect they port THEIR turbos for free which probably help Dean out but as for my bodged effort it probably wont :D

EPIC not really. Unhelpful yes.

If you ask nicely and don't have a history of being a BEGI-hater, they port ANY turbo for free. Stephanie has said that here before. And they did a fine job porting mine. (Disclaimer: my MSM's stock IHI turbo did come from BEGI, but they agreed to port my original one from Mazda before I decided to buy a new one.)

Oh rly... if begi will port the MSM IHI for free, I have no choice but to buy that fancy seperated-gases downpipe.

That isnt just nice that is freaking awesome and given it is the high standard of work that caused my worry it may be worth me asking if i get problems.

The very first S4 turbo kit in the UK did hit over boost. But this was two years ago with a standalone ECU. Consequently, this is what lead us to porting turbos. So I would suspect that your friend's turbo is not ported. I suggest porting it or going to a lower psi actuator. The only kits that experience over boost right now are the shanghai kits (can't explain that one other than it's Chinese QC) and the kits using EBC. I have kits that do not over boost until an EBC is added. So if your friend has an EBC on his car, I would also suggest removing it. That said, I swear I was told by MX5Mad that his over boost problem was solved. Is it still having problems?

And yes, we will port any turbo at no charge.

You cannot add an external WG to the standard S4 manifold. It will crack. Two attempts resulted in two failures. A third attempt is out in the field, but I would not hold my breath. At this point, if you want to go EXT. WG, you must use a cast manifold, add the Ext WG, and modify the downpipe. We do have a new S4 w/ V Bands and Ext. WG coming soon though.

Stephanie

Yes it was two years ago with an Emerald K3 ECU with EBC via a solenoid valve on Deans car. I'm not sure who engraved the airbox with the BEGI logo and first installed writing but I thought it was very nice. I was under the impression that they added an external to his setup to aid control but I can check this next meet. His problem was certainly solved and it boosts up spectacularly and goes like a pig on fire.

Well I'm actually hoping to copy the S4 manifold but add my own ideas for my setup and because of Dean's teething I thought I'd ask the people in the know.

Thank you Stephanie