Wastegate size

[midnightrayne]

Hey guys another question. my manifold that i love dearly came with a 46mm plate for the external wastegate now my question is, isnt that a little big for what i am doing? what is the difference in the sizes? if i was to have the 46 cut off and put a 38mm would that be better or not worth it?

Also how many of you guys dump it or do you run it back into your exhaust stream? what would be the benifits of either way?

Thanks

[high c]

im dumping to atmosphere. I would assume the benefits come from dumping the gases out there rather than having it head through the rest of the exhaust, decreases back pressure, and just sounds way way way way WAY better

[Boost_Lee]

if you are going for moderate boost levels, a 38mm will suffice, but im not sure if a 46mm will be fine. You might just have to spend a little more on a 46mm than a more common 38mm

[midnightrayne]

if you are going for moderate boost levels, a 38mm will suffice, but im not sure if a 46mm will be fine. You might just have to spend a little more on a 46mm than a more common 38mm

HAHA thats what i am trying to get around the cost is a ton more. for something i really dont think ill ever use to its fullest.

[NAiL05]

Ebay it lol. But damn thats a pretty big flange. What type of manifold did you get? My friend also dumps into atmosphere haha shits pretty loud when he talks to me on phone when driving haha he should be at the meet =D. I think he might have an extra wastegate but I think it was 38mm I will double check with him. If all else fails you can try making an adapter plate for something smaller or just hack the stock tubing and weld on a 36/38mm flange.

[midnightrayne]

yeah thats what i think i might do cut mine off and put another on there. my mani is the sx power for the 4g63 t4.

[aleks77]

After reading a lot of threads on honda-tech i went with a 38mm TIAL, and im planning on making over 400whp.

[midnightrayne]

WAYYYY more than i want, im looking for a respectable 250whp so the 38 would be alot better all around i think, thanks guys now to find someone who can weld stainless...

[foamypirate]

By the way, a common misunderstanding is that you need a bigger wastegate for higher boost levels. Think about that. The higher boost you run, the more exhaust you are using to spin the turbine, and the less you are releasing out the wastegate... You really only need a larger wastegate if you are running a huge ass turbo at low boost settings.

Just a little tid bit for you all.

[midnightrayne]

well im planning on running one of these two turbos ane only running tops of 12psi more like 8-10. do ya think i still need the 46mm???

Im thinking im going to run a garrett turbo with these specs
t3/t4 50 A/R COMPRESSOR .63 A/R TURBINE .57 TRIM
or this one
T3/T4 .50 COLD .83 HOT .56 trim

I havent picked which one yet, if you guys have an opinion on which one i should get let me know.

[bruno8747]

well im planning on running one of these two turbos ane only running tops of 12psi more like 8-10. do ya think i still need the 46mm???

Im thinking im going to run a garrett turbo with these specs
t3/t4 50 A/R COMPRESSOR .63 A/R TURBINE .57 TRIM
or this one
T3/T4 .50 COLD .83 HOT .56 trim

I havent picked which one yet, if you guys have an opinion on which one i should get let me know.

38mm wastegate will suffice for those turbo's at that boost level. The 46mm and up are only going to be useful if you have a GT35 or GT40 or a really big turbo like that.

[fast93accord]

on my currently broken turbo i ran a 38mm internal wastegate... with a 60-1 and td06h turbine i didnt have any boost creap for as little as 12psi. I had it at 20psi a few times and with my electronic boost controller built into my AEM EMS and a GM boost solenoid and never had any boost creap issues. I'm pretty sure a 38mm is good to over 400whp. I'm sure a 45mm wouldnt hurt for above 400whp, but 38mm will do the trick for lower for most basic setups