T25 boost question

[yoshimitsuspeed]

I just put a T25 into my Mk1 MR2. I was hoping to start out around 10 psi then build up. Seems like I am getting 11 to 12 but spikes as high as 14 and this is a little higher than I was aiming for atm 12s ok but I'm not stoked on the 14 spikes.
This is with a new Autometer gauge plugged into the intake mani and the vacuum line out on the compressor housing plumbed straight into the waste gate.
I did clock the compressor housing and re drilled and tapped holes for the WG but I was very careful to keep the alignment the same.
Is this normal or is the wastegate sticking or some other issue I need to worry about.
I just don't want' to spend hours trying to fix it if it ain't broke and don't want to drive it if it is.

 

[the_mork]

I'm not sure what displacement your motor is or its VE but you may need to port your turbo and wastegate as well as your o2 housing in order to handle what could be a faster buildup in exhaust gases.

Are you just spiking and then falling or are you spiking then creeping?

 

[Xit40]

it's most likely a 1.8t. Spiking a couple psi higher than the wastegate is set at is nothing unusually. Are you using anything besides the wastgate the control the boost pressure?

 

[yoshimitsuspeed]

I'm not sure what displacement your motor is or its VE but you may need to port your turbo and wastegate as well as your o2 housing in order to handle what could be a faster buildup in exhaust gases.

Are you just spiking and then falling or are you spiking then creeping?

It's a 1.6 liter. I ground out the step on the mani side of the turbo and did a light gasket match on both sides. It's just spiking then dropping down to 11ish after a sec. I made my own piping out so right after the turbo it's 3" with a 2" wastegate pipe out into the exhaust no 02 housing. Haven't seen any creep and I doubt I will .

Xit40 No boost controller. It's plumbed straight from the turbine housing to the WG.
I have gotten a couple replies from other MR2 owners who are running this turbo as well sounds like 14 is pretty common. I thought it was lower but oh well. Guess I'll just have to make sure everything is dialed in to handle it. Shouldn't be too hard.

 

[the_mork]

The spike probably shouldn't hurt anything.

 

[Xit40]

If you were so inclined you could get a wastegate actuator that is set to open at a lower pressure or modify the one you have to open sooner. That way you can turn it up if you desire, but you'll still be able to turn it down if it causes you problems. You can check this out if the spiking or high pressure the wastegate opens at bothers you.

 

[yoshimitsuspeed]

If you were so inclined you could get a wastegate actuator that is set to open at a lower pressure or modify the one you have to open sooner. That way you can turn it up if you desire, but you'll still be able to turn it down if it causes you problems. You can check this out if the spiking or high pressure the wastegate opens at bothers you.

Thanks for the link