I just have swapped my 2.25" downpipe to 3".

But i get horrible boost creep now (MBC set for 9psi -> it creeps up to somewhere 15+ in VTEC - didn't dare to try the max.). Even in second gear. I think it is worthless to port my internal wastegate, better swap to external now.

I don't want to buy too small, but too large either. what size do you suggest for ext. wastegate? 38mm or 40mm?

I want to get rid of boost creeps forever.

 

need more info, like what engine/turbo, what are your goals? Are you going to be upgrading sooner or later?

 

you have boost creep with an internal gate? Is it getting hung up or stuck make sure the actuator is working properly or try another MBC, is there a crack around your internal wastegate port?

If you do go External 38mm will be fine for most setups and i don't think you can really go to big with a external, i think the later ones would just be more efficient on a higher boost app but most people run tial 35/38mm with no problems

 

My goal is 250-270 HP. I have B16A2 with T3/T4B (9-11psi).

 

an electric boost controller could do alot to help combat your boost spiking issues

 

It won't help. this is not boost spike, but boost creep. I have tried it with a friend of mine's avc-r.

 

haha oops yea i dont know what i was thinking :1

 

I have ordered a 38mm lame XSTurbo wastegate. My first chinese stuff. I read in spite more ppl satisfied with the wastegate (not like manifold and turbo). diaphragm probs only at a few ppl (55 USD is a replacement one from Tial). Hmmm. I'll see it in 2 week

 

i've seen people do 300+ on a 38mm tial with little boost creep. Depends on the dump tube if used too.