External wastegate??????
- Thread starter 10secvega
- Start date
DailyDrifter
The Slow and the Curious
- Joined
- Dec 5, 2007
Looks like a 38. Get a boost controller, but I dont know if you'll be able to get it down that low even with a controller. If you cant find a spring you could cut it down, but I would try and find a spring first.
You should probably start with an 8# spring and see how much boost you can get out of it - depending on your setup it may not make 25#s with an 8# spring. You will more than likely need CO2 or Nitrogen to the top of the diaphragm to get the range of control you want.
I would be careful with the spring pictured as it appears to have been cut. One way to see what you've got is to install the spring with zero tension and apply air pressure to the bottom of the gate and see how many #'s it will take before it opens. You will need a regulator with a low pressure gauge attached to achieve this - or just put the spring in with zero tension, run your reference line from the turbo to the bottom of the gate with nothing on the top and see what you get.
I would be careful with the spring pictured as it appears to have been cut. One way to see what you've got is to install the spring with zero tension and apply air pressure to the bottom of the gate and see how many #'s it will take before it opens. You will need a regulator with a low pressure gauge attached to achieve this - or just put the spring in with zero tension, run your reference line from the turbo to the bottom of the gate with nothing on the top and see what you get.
Not sure of this but looks to me like the spring may have been cut already (usually the coils will flatten out at both ends, not just one end). I'd measure the valve (I agree; looks to be 38mm) and get an external WG downpipe (if you don't have it already) and install everything and see where you're at (carefully in case it is a heavier spring than what you want--be ready to let off the accelerator very quickly if needed) before trying to make changes. Install the wastegate without the boost controller first, running a line straight from the compressor housing to the lower port on the wastegate. Leave the upper port open to the atmosphere so you can see what just the spring gives you as far as boost.
I am running a billet 6765BB with Tial 38mm and a 5.8# spring along with the AMS-500 and have gotten as much as 18# without putting much pressure on the top side. I haven't even pushed it yet so you may be OK. BTW - that looks like it might be an old Innovative Turbo 38mm gate.
10secvega,
Just a thought, but I'd probably go with a spring that's lighter than 8 psi and use a 2-stage boost control setup to control your launch boost and your boost going down the track. This will allow some room for adjustability in case you want to leave at a lower level of boost. The spring only sets the minimum level of boost you can get; the maximum level is determined by what your controller is rated for and set at (i.e., if it's allowing the top of your wastegate's diaphragm to see the same pressure as the bottom side, plus you have a spring of any rating pushing on the top side, the WG will not open and you can have all the boost you want).
I found this webpage a long time ago and saved it in my favorites, as I may do this on my car too someday. Should be very helpful with plumbing a 2-stage boost control setup:
boostcontrol
Just a thought, but I'd probably go with a spring that's lighter than 8 psi and use a 2-stage boost control setup to control your launch boost and your boost going down the track. This will allow some room for adjustability in case you want to leave at a lower level of boost. The spring only sets the minimum level of boost you can get; the maximum level is determined by what your controller is rated for and set at (i.e., if it's allowing the top of your wastegate's diaphragm to see the same pressure as the bottom side, plus you have a spring of any rating pushing on the top side, the WG will not open and you can have all the boost you want).
I found this webpage a long time ago and saved it in my favorites, as I may do this on my car too someday. Should be very helpful with plumbing a 2-stage boost control setup:
boostcontrol
I just purchased a AMS-500 boost controller.
I thought i needed the 8 lb spring to set my launch boost,then the controller takes over from there. I may only be limited to an additional 14 lbs without CO2,but won't know till i get it together and tested.
I know my car dead hooks on 8 lbs off the trans brake.
I thought i needed the 8 lb spring to set my launch boost,then the controller takes over from there. I may only be limited to an additional 14 lbs without CO2,but won't know till i get it together and tested.
I know my car dead hooks on 8 lbs off the trans brake.
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