Helper spring?
 

I'm just wondering what type of spring you guys are using for your wastegate? Length and stiffness? I'm not sure what to go look for.

Don't know; just went through my junk boxes untill I found one that seemed pretty strong. Connected it to the wastegate and then used a small piece of chain to a convenient bolt to adjust tension.

https://www.miataturbo.net/forums/vb...etimage&id=430

This is what I used. Not sure how much tension is needed since I've yet to fire the car up since installing it.

most definitive thread I've found on specs
http://forum.miata.net/vb/showpost.p...85&postcount=1

which heatshield is that and how did you plumb that recirc fitting?

that is a pretty sweet idea, easy to dial in?

It is a Tarmac heat shield, they stopped making them after a short time.

The recirc fitting is a nylon fitting from McMaster into a tapped hole in the AFM(only about one turn of thread due to the thin wall)

So judging by that post, I need a pretty stiff spring. Off to Home depot.......hehe.......Only on a Greddy.:bigtu:

I was surprised it was that beefy- tho it is on a big turbo. I was going to follow that setup, just haven't got around to it yet. Post back when you get it together.

Has anyone swapped the weak ass greddy actuator can for a "real" actuator?

probably not, considering the springs works and is cheap and easy :gay:

Don't know yet, have run the car with that setup. I might have to shorten the spring a little to gain more adjustability.

I tried several Home Depot springs. I didn't do any fancy alooominum fittings onto the wastegate actuator though. I just stretched the spring from one of those screws with the eye in it for adjustabiilty, attached to the actuator fitting, and looped it over the back. I had to smash the end of the spring a bit, but it works and it's a quick 5 minute job.

I eventually went with an 11.4(?) kg spring. With a combination of the adjustable screw, the adjustable wastegate actuator, and just stretching portions of the spring to lessen the tension, I was eventually able to dial right in on 11 psi. Now I just use the adjustability of the spring on one end and the actuator on the other as kind of a ghetto MBC to go between 7 and 11 psi.

pics? :redx:

http://www.cardomain.com/ride/590477/2

I haven't updated anything in awhile, but this pretty much shows my ghetto set-up and the dynoplots. I've played with the springs since then, and I think my set-up is holding boost better through the rpm band now. I just need to deal with my fueling issues and get a decent enough tune to get back onto the dyno for fine-tuning and power runs.

Nice stuff. Thanks for the post and the information. I'm just curious would an O2 Signal modifier help out that lean spike in your A/F graph? It looks to start occuring well before you go into open loop mode, so wouldn't an O2 clamp help?

that looks good- and the spring is a lot smaller than the one I referenced. But the adjustability looks like a very good idea. And your setup is a good example of what the spring can do- that's a huge drop after the spike.

Np,

Yeah, I can't remember exactly what the part number for that spring is. If you need it, I can get it no problem.

No doubt about the clamp. These runs are almost 3 years old now. I've done a lot of work on my set-up since. I installed an O2 clamp last week. If I can work out my fueling and dial in my tuning for 10-11 psi again before the end of my vacation, I might take my car in for some dyno runs. :bigtu:

YA! Wouldn't mind a part# if you have it handy.

SP-9608: 11mm x 6.4 cm x 1.2mm, 11.5 lbs