Debating: 3" SV (internal) vs. external WG?

[Clay]

Im debating on getting a 3" SV vs. just going to an external WG.

what are the pros/cons of each? why should I have one over the other.

This is on a street/strip car, so if that makes a diff. let me know.

thanks!
clay

[Frank]

depending on the size of the external wastegate, you get differrent amounts of control. I perfer the 3" swingvalve since it doesnt require another flange on the header and more tubing and a more expensive part/setup.

3" swingvalve rules on these cars.


Frank

[slasky]

I have a 2.5 swingvalve on my car and I have run a best of 12.44 @ 112. I am going to turn up my boost next season and hopefully hit the 11s. What improvement would a 3 inch offer over the stock 2.5?

[glhs875]

Normally a good flowing IG setup is fine. But on my car the IG does not flow enough exhaust to control the boost, and starting at about 5000rpm up, I've got MASSIVE boost creep! Until I convert over to a higher flowing EG (soon), I'm using my BOV to control the creep. It works, but not a great thing to do. This is the first combo I have had that the IG wouldn't work on. But then this is the first 8V I've had that will pull to 7800rpm, maybe even higher!

[glhs875]

I have a 2.5 swingvalve on my car and I have run a best of 12.44 @ 112. I am going to turn up my boost next season and hopefully hit the 11s. What improvement would a 3 inch offer over the stock 2.5?

Possibly a little less backpressure after the turbo, which could result in more HP. I have a custom built 4" swing valve/ downpipe on my car. The downpipe flows plenty, but the IG swingvalve doesn't flow enough for my combo.

[cordes]

Unless it were an all out effort, I would stick with the internal gate to save both cost, and to minimize the ammount of work needed to make it come together.

[glhs875]

Unless it were an all out effort, I would stick with the internal gate to save both cost, and to minimize the ammount of work needed to make it come together.

That's what I was trying to do. But it didn't work on my clunker.

[Clay]

Unless it were an all out effort, I would stick with the internal gate to save both cost, and to minimize the ammount of work needed to make it come together.

well, considering the cost of a new 3" SV, I would say its a wash as long as you can do the extra work for the external WG yourself. BUT, for me, it sounds like it will be a while before I need an external WG, so Im probably going to go the 3" SV route for now.

thanks!
clay

[Terry Again]

Hi, I assume your getting the 3"sv from TU? :amen: I wish I had the bucks to do the package they have!! From what I've read about SVs and increasing the size is most if not all ignore the size of the puck and opening when going larger! the size of the exhaust opening part of the SV is only a part of getting exhaust out. The TU piece takes care of that problem I think.
Have fun,
Terry

[8valves]

Normally a good flowing IG setup is fine. But on my car the IG does not flow enough exhaust to control the boost, and starting at about 5000rpm up, I've got MASSIVE boost creep! Until I convert over to a higher flowing EG (soon), I'm using my BOV to control the creep. It works, but not a great thing to do. This is the first combo I have had that the IG wouldn't work on. But then this is the first 8V I've had that will pull to 7800rpm, maybe even higher!


Where do you have your cam set to want to go THAT high? Mine doesn't want to go there, and I can't think of what could be holding it back.

AM

[glhs875]

Where do you have your cam set to want to go THAT high? Mine doesn't want to go there, and I can't think of what could be holding it back.

AM

Well I was a little off on how high it was pulling to. It sounded like it was hitting the rev limiter I had set @ 7800 but I'm not sure yet what is up with that. It seems to only cut out in 1st gear only at around 7300 to 7400rpm. It will pull cleanly past that point in 2nd. I haven't tried 3rd. I would be doing 150+mph. I had to get some 7K chips for my shift light as my factory tach is now kinda useless now, to find out for sure where the peak power was. The engine is actually only making good power to 7200rpm then it starts to fall off some. I have the cam at 2deg retarded right now, but it was still pulling to that point at 2 deg advanced just not as hard. I can't tell that I lost any bottom end torque with it retarded, if so not much. It still idles 14" to 15" at 1100rpm. But not at 14.7 to 1. This cam likes to idle and actually cruise richer than that. But it does cruise okay at 14.7. I actually had to add more fuel down low and across the board with it set this way. It will easily hit 7200 in 2nd before an 1/8th now from a dead stop. Which is well into the 90's for mph on just 18psi. I haven't taken it to the track yet to verify, but my test strip is pretty accurate. I have a 3.22 final drive. I have found some HP here lately in my tune. I hope to find some more and a few hundred more R's. I would like 100+ mph in 2nd with the gearing I have now. Undoubtably, my head must be breathing pretty well. The ports are larger than what I have seen people using except for Stephane's 8V head that I've seen pictures of. I want a high lift cam, like at least in the .550 area. I think that could make a huge difference. I still have the intake and lots of other mods to help upper RPM HP left to do yet. It's starting to get interesting.

[8valves]

Well I was a little off on how high it was pulling to. It sounded like it was hitting the rev limiter I had set @ 7800 but I'm not sure yet what is up with that. It seems to only cut out in 1st gear only at around 7300 to 7400rpm. It will pull cleanly past that point in 2nd. I haven't tried 3rd. I would be doing 150+mph. I had to get some 7K chips for my shift light as my factory tach is now kinda useless now, to find out for sure where the peak power was. The engine is actually only making good power to 7200rpm then it starts to fall off some. I have the cam at 2deg retarded right now, but it was still pulling to that point at 2 deg advanced just not as hard. I can't tell that I lost any bottom end torque with it retarded, if so not much. It still idles 14" to 15" at 1100rpm. But not at 14.7 to 1. This cam likes to idle and actually cruise richer than that. But it does cruise okay at 14.7. I actually had to add more fuel down low and across the board with it set this way. It will easily hit 7200 in 2nd before an 1/8th now from a dead stop. Which is well into the 90's for mph on just 18psi. I haven't taken it to the track yet to verify, but my test strip is pretty accurate. I have a 3.22 final drive. I have found some HP here lately in my tune. I hope to find some more and a few hundred more R's. I would like 100+ mph in 2nd with the gearing I have now. Undoubtably, my head must be breathing pretty well. The ports are larger than what I have seen people using except for Stephane's 8V head that I've seen pictures of. I want a high lift cam, like at least in the .550 area. I think that could make a huge difference. I still have the intake and lots of other mods to help upper RPM HP left to do yet. It's starting to get interesting.

Now it makes sense. I'm at 5* adv on a S3... time to start playing with that again. I just set it one day while driving around and never got back to playing with it, I guess it's time.

I'll take some pictures for you of my head, Bryan damn near broke through on a couple of ports... we actually pressure check it every time it's off just in case. :p

AM

[glhs875]

Now it makes sense. I'm at 5* adv on a S3... time to start playing with that again. I just set it one day while driving around and never got back to playing with it, I guess it's time.

I'll take some pictures for you of my head, Bryan damn near broke through on a couple of ports... we actually pressure check it every time it's off just in case. :p

AM

When I was at 6deg advance, peak power was around 6400rpm. That's where I was shifting at when I ran the 8.33. I feel like the hyd. lifters are starting to hold things back some in the upper R's. I'm going to solids real soon, along with some titanium retainers!!! I'd like to see the pictures.