Turbo spooling question, possible overboost?
 

I've had this problem for a little while now. With my greddy td-04 turbo, 19T compressor wheel, with a 6 lb internal wastegate. The car spools fine up to six pounds, stops, and then continues on to 10 pounds by redline. What I believe it is, is that either the wastegate is open and the turbo keeps spooling because of my 19T compressor wheel, or the wategate is hitting the DP. Any thoughts/ ideas on whether my thoughts are right, or if it may be something else. And also any ideas on how to fix the problem would be greatly appreciated.

Also, the DP is the 2.5 inch that comes with the turbo in the kit. And its a top mount if that makes a difference.

Hmm first make sure the flap doesnt hit the dp if thats the case you needz a spacer. If thats not the issue just get a MBC .. $9 from ebay. Problem solved.

Im actually surprised you havent done some serious damage to your engine. What are you using for engine management?? IC??

I had a MBC on it before, is there any easy way to check if the DP is hitting the WG?

And I'm running IC with megasquirt installed probably this weekend


I know that i could hurt it, which is why i dont drive it hard for the time being.

Shit the only way I think you could check is to manually pull the wastegate arm till the flap in the back is fully open. IF the flap is hitting the DP then you should hear the collision of the two metals. Or you could unhook the arm form the flap and play with the flap and see if it hits the DP.

ok, I've played with it before and never heard metal on metal. I wasnt really listening for it though, I'll go and check it in a few minutes...

Its near impossible to tell because as the WG turns it makes a good bit of noise at the connection to the lever and the actuator rod. Sooo, i cant easily tell if its hitting or not...

a boost controller only makes the boost go up, not down

I know, thats why i took it off.

Oh I thought it could help you set a steady boost level. So whats up with the wastegate flap??

Disconnect the wastegate actuator and see if you are making boost. Then check out how much it opens connected vs disconnected. This should get you well on your way to figuring out the issue.

ok. What would that tell me?

With the WG disconnected it will continue to spool...

With it connected it would just continue doing what it is doing... right?

Im kinda lost now ><

with the actuator disconnected it basically opened all the way up, so if youre still able to build boost then you have need to fix the DP or port the turbo or both. Just do a pull through 3rd gear

*Facepalm* i knew that! for some reason i thought you meant to disconnect the high pressure line to the WG. ok, that makes sense.

I'll be trying this tomorrow when there is sunlight and warmth.

Disconnect the wastegate to the flapper and turn the flapper manually (engine off of course) See how far it opens.. if you hear it bang against the dp you need a spacer.

check this out
https://www.miataturbo.net/forum/t39098/

Whats a good site to get the spacer at?

What kit do you have? Perhaps begi should be able to help u?

He said greddy kit. Didn't he? I thought I had the same issues, but my wastegate fell off at a trackday (damn chra bolts :vash:). I made no boost, no power, and exactly 14.7afr. I think it's a symptom of the small wastegate port on the greddy kit, some say porting it helps.

yea, its a greddy td-04

It appears to be that BEGi has stuff for t3 t4 t25 and t28. nothing for td-04

What are you looking for? Have you figured out why you are having this problem?

Look for solutions after you've figured out the problem. Did you do like I suggested?

I had said that I was going to do it in the AM. By AM i didnt quite mean 3 AM :laugh: I will be doing it later today... i guess? But I figured that I would look into possible solutions for when my friend and I figure out the problem.