Boost controller VS Exeternal WG spring size question

[87turbot-type]

Im getting ready to intergrate my inovative boost controller into my setup's equation. Last year I didn't run a boost controller and just used different WG springs to contol the boost pressure. I want to try to use the controller to stabilize the boost as on all my logs my boost pressure is very spikey and all over the map.

With my current setup (T-netics RG45WG through a ported turbo hole) with the 5 psi spring I run a min 17 psi of boost
With the 11 psi spring I run 20 psi of boost

I want to decrease the spool up time and not open the gate till closer to the boost level I want to run. (min 20 psi) And also try to flat line the spikes. Since the gate is opening currently at 11 psi the boost climbs slowly once it hits 17 psi with the 11 lbs spring in it and fluctiuates between 18-21lbs in high gear down the track.

So now to my question. Am I best to use the 5 lbs spring in the gate and use the controller to use boost pressure to work with the small spring to keep the gate closed to keep the fluctuation down? Or should I use the bigger springs an boost pressure to control the boost. Which should work better?

The 5 lbs spring is back in the car now and I have done some test runs on the new xfi and got the fuel and timing maps close, so I'm now ready to run the higher boost numbers. I've also noticed that the xfi being able to add extra timing and fuel during spool up has helped speed up the turbo.

Thanks Brandon.

 

[87turbot-type]

No one has any suggestions?

Weather is finally starting to get better. Have everything nailed down in my program with the small 5psi spring. I'm going to start doing some testing slowly increasing the boost controller opening boost pressure and see what the logs say.

Brandon.

 

[TurboBob]

what kind of controller?

 

[87turbot-type]

Innovative MSBC-1 or Deeds as they used to be called

 

[TurboBob]

I've never used that one personally, but if you are not using CO2, you may not be able to go as high as you are hoping. The backpressure in the header tries to push the gate open, and having CO2 helps overcome that.

post back your results.

Bob

 

[SHADOWII]

Your experimenting w/the differant springs shoud have given you a good idea of your min/max boost capabilities which will be helpful in your w/g -controller programing. The combination of turbo and w/g is what will set your min/max boost limits and the controller will allow you to operate/experiment w/in those parameters. the lower spring pressure should be a good place to start and safely gain the knowledge needed for the all-out assault.

 

[87turbot-type]

Thanks Bob. I am actually having the oposite issue than most have and that I think your refering too. With my smaller compressor not taking much work to get spinging I am building boost too quickly. I'm not having an issue keeping the gate closed to achive my boost level required, but rather having an issue with when to open it to gain max spool time and be able to slow the compressor down enough without having excessive spikes.

I will do some testing in the next week or two and post my results both with the small spring and larger spring and record my spool time differences. With pump gas I don't really want to exceed 22psi. I am also working on installing my alky kit the way I want it and than will do some more testing at higher boost levels. I'm not sure of the max boost levels I will be able to achive but it should go as high as the exhaust wheel will let it. I would think at least 25-26psi

Most of the issues I am having are due to having the waste gate plumbed into the turbo hole instead of off the header which would be best for boost control. Also having a small turbo.

I thought it said in my sig but I am using a 6131DBB turbo

Thanks Brandon

 

[20psiofevil]

Sonds like you're having issues with that gate. You should not be having any boost control issues with a 45mm gate. Maybe location? I'd pull the top and check the diaphragm as well.

Dont remember the exact but think that when using a mbc you dont want boost to exceed 2:1 of spring rate. so for a 10psi spring you dont want to exceed 20psi. Back pressure will cause the gate to open prematurely.

I run a tial 38mm on the crossover and have it dumped to atmosphere. 10psi spring and see 10psi on the manifold.

 

[87turbot-type]

I'm not having issues with my gate. I am having issues with location of the gate but I know that and it shouldn't have any effect on the operation of the gate once I start to get up over 20 psi. There is really no reason for me to have a 45mm gate when I hav a 30mm tops hole in the turbo going to the gate. I will be moving it once I am ready to switch turbo's and goto a larger 4 bolt turbo with v-band and gate off the header. I would love to dump to atmosphere but have a feeling that it might be abit of a noisey draw to the car and don't really want to get pulled over for that.

Thanks Brandon.

 

[20psiofevil]

Brandon, the gate stays shut until you get into boost. Normal driving will sound just like it does now piped into the downpipe. So unless you're boosting the engine in front of a cop no extra attention will be drawn.