hally

Hi,
I've installed a tial 38mm dual port wastegate.
Initially I simply let the spring pressure (.8bar I think) regulate the boost level. (hose to side port only). Boost occilated between say 12-14psi as the wastegate opened and closed.
I fitted a manual boost controller today (the lindsey unit sold by paragon) and attempted to dial in 16psi. This was roughly achieved, however the boost occilation was still present, just not as exagerated, about a 1 psi occilation this time. Great if you were attempting to test a traction control system, but not the smooth ride I am looking for
I've read so many posts saying that EBC is not nessasary so I am thinking that others don't have this problem with their MBC??
Any ideas appreciated.
thanks

J Chen

Hi Hally,
Are you taking about boost spike ?
If so it's normal with Lindsey &
Reliaboost. I'm also seeing a spike
of 1 psi.

hally

na, my issue is not a boost spike issue, its about achieving smooth regulation of max boost on a dual port wastegate. Its occilating as the wastegate opens and closes.
cheers

Fen

I have a TiAL on my Turbo - I didn't fit it myself but I know it hasn't got an EBC and it was soooo smoooooth until I broke the engine

turbo951fan

It shouldn't do that, something's wrong.

Flight_951

I haven't seen the oscillations you're referring to. I've heard there's a suggested spring rate that's basically a percentage of the boost you intend to run where the tial works best. Your .8bar spring should be okay though. I use a 1bar version and run about 16psi. Is your bov working?

NZ951

1psi? That is nafff all movement with a EBC in my experience.

MySwiss

hally. It sounds like you have a leak in your pressure line ,to the side port or in the other vacuum hoses. Cause I run a 9psi Tial at 16psi, all the time, and it's rock solid.

Your Tial should only open at 11.6psi. In my experience, Autometer gauges and others , tend to show 1psi more or less then actual manifold pressure.

Check for leaks, and make sure all your hoses are tight.

tazman

Did you check to make sure there was no jet in the banjo bolt?

hally

no jet in banjo bolt - will check for leaks thanks

hally

OK I checked all the lines from banjo bolt to wastegate, found one leak, bit embarrasing as I forgot to tighten the side plugs on the MBC and one had worked loose.
This improved things substantially, Its bearable, but there is still say 0.5psi occillation.
I guess this improvement suggests that there are still further vaccum hose leaks elsewhere...

Flight951 what was your thinking on the relationship of the BOV to this problem.

Thanks everyone I feel like I am on course to solving this.

Sam Lin

Do you still have the stock cycling valve in there?

Sam

Flight_951

My thinking is that I believe the stock bov is worth checking if not replacing with a better one when troubleshooting boost/underboost problems. The stock bov has been improved upon with the 993 version ($35), and many aftermarket pieces. If this is the first time you went to 16psi with your car, the stock bov could have been not working properly.

If this swap does not affect the boost condition you're having, the metal internals of the new bov will still protect against failure and grenading your turbo. I learned this the hard way.