Straight outa the exhaust housing?

[WickedShelby88]

Well the other night after thinking about all these debates on headers I was remembering a lot of what the Ford guys did with their SVO's to make them spool. Most of it happened right at the exhaust housing. Those cars use a cast iron elbow with a 90 degreee similar to ours. Granted when you go with the bigger aftermarket swingvalves you breath a lot better there but its still not as straight as it could be. What do you guys think about using a Ford style exhaust side T3 and then using a section of a 3" downpipe with a flange that bolts directly to this and then angle it down towards the K, but instead I plan on cutting the middle out and welding tubes in to hold the rack so there is MUCH more room there. Not to mention I will be getting rid of the PS pump. What gains would you expect from this? I know on an SVO when you use a straighter downpipe throttle response is much better and you can feel the HP difference to the tune of about 35 for a stock engine and on up with other mods. Another interesting thing is they are claiming that by running a larger TB in conjunction with this you get V8 throttle response because the amount of air coming in becomes nearly equal to that coming out. I know this is all very general so I hope it makes sense. I know we aren't exactly comparing apples to apples here but the engine is close in size and still uses 8 valves.

[Birddog]

Are you talking about switching over to a standard T3 or just the swingvalve?

Or like when you cut the 90 off the Ford SV and weld a 3" pipe straight in?
I had something like that on my 86 SVO from this guy. Between that and the header the car ran like a scared rabbit but the header killed the low end a bunch.

[turbovanman²]

You kinda lost me but yes, the stock SV is a big restriction but remember, they also control boost so if you remove it and just run a large 3 inch elbow, you need to run an external wastegate. Yes, its a good idea to open it up and will make alot of gain. So far, the 52mm t/b seems to make the most power on our 8 valve engines, 16 valves is another ball game.

[Ondonti]

just running 3" swingvalve but actually having an external gate would help power a lot.
The big powerloss is the two exhaust flows coming together...and the horrible placement of the swingvalve exhaust flow.

That SVO internal wastegate pipe still is a horrible design. Flow comes together right in front of the turbine blade.

[Birddog]

You kinda lost me but yes, the stock SV is a big restriction but remember, they also control boost so if you remove it and just run a large 3 inch elbow, you need to run an external wastegate. Yes, its a good idea to open it up and will make alot of gain. So far, the 52mm t/b seems to make the most power on our 8 valve engines, 16 valves is another ball game.

This one just cuts the elbow off the SV, the puck and arm stayed in place for wastegate duty. It may be able to be ordered unassembled so you could clock it and weld it up on your own too.

[turbovanman²]

The SV is the restriction so unless you make the hole bigger then its pointless.

[8valves]

The SV is the restriction so unless you make the hole bigger then its pointless.

I'm not sure how you can say this... I won't disagree that the SV isn't a restrictive setup all on it's own, but making a lrger flowpath aft of it will show gains. Look at a TU 3" swingvalve... HUGE gains over the 2.5" simply because the area rigth around the valve is much larger allowing quicker evacuation into the downpipe.

[turbovanman²]

I'm not sure how you can say this... I won't disagree that the SV isn't a restrictive setup all on it's own, but making a lrger flowpath aft of it will show gains. Look at a TU 3" swingvalve... HUGE gains over the 2.5" simply because the area rigth around the valve is much larger allowing quicker evacuation into the downpipe.

Yes, I agree and thats what I was trying to say but look at the exit of TU's SV, its HUGE,

[Birddog]

And a 3" SV that goes straight out with a long sweep 90 instead of hanging a tight sweep wall right after the turbine should flow better.. Right?

Before the header I went from a stock Ford SV housing with a 2.5 DP section into a 3" exhaust to a full on 3" Stinger "style" SV/DP combo and the difference was noticeable to say the least.. (on a stock "big"T3)
Of course now we're comparing footballs to oranges...

[Pandemoniac]

sems to make sense to me, the exhaust wants to travel straight out from both the swing valve and the turbine, and our housings makes it do a tight 90 degrees. For a race only car if you have no power steering pump you could have a big-assed 4" pipe just pointing straight out and exiting out the fender, that's as close to a zero-backpressure exhaust as one could imagine! Just modify a swing valve like the one in your pic, but just with a straight pipe.
And what you're saying about a "long sweep" bend makes sense to me too.

[turbovanman²]

Exhaust doesn't want to bend so anything you can do to keep the flow straight will help.

[Birddog]

Didn't mean to come off as ----y but I deal with flow every day...

Granted it's water but the principle is the same.

A 3" ell has the frictional flow loss equal to 8' of straight pipe. Again.. Water flow. But I figure the farther you place that 90 from the discharge the better.

[tryingbe]

Speaking of exhaust, I think TIII have better turbine housing and elbow than TII.

Wastegate hole comparison.

[turbovanman²]

The TIII elbow flows huge,

[GLHNSLHT2]

that's what you have to do when you choke off a head with a small turbo. Make the wastegate bigger

[WickedShelby88]

Sounds like a plan.. Yes I totally plan on using a quality external wastegate like a lot of the big power SVO guys are running. Yeah I was going to get that same part you got Sean, but ran out of money fixing everything else that went wrong. All and all it was one of the best cars I've ever owned. It ran 13's and got over 25 mpg on the highway. I put 26k on it the first year I had it. All with a fairly stock engine with crower rods and forged slugs. The cam is what made it rev. It was running an esslinger and I could bounce off the rev limiter in every shift If I wasn't careful... I want my shelby charger to do the same when I'm done... This is why I brought up this thread. I HATE turbo restrictions. and by golly that swingvalve is the BIGGEST one compared to even the aenemic head flow..

[moparzrule]

If you run a ford style turbine housing like I am going to, this is about the best setup for our cars-

http://www.atpturbo.com/Merchant2/me...egory_Code=BCS

And here we have a choice on long leg or short leg 90* pipes, I am not sure if we can fit the long leg on our cars with power steering or not. To me it looks like we could fit the long leg even with power steering but who knows-
http://www.atpturbo.com/Merchant2/me...egory_Code=MDP
http://www.atpturbo.com/Merchant2/me...egory_Code=MDP

[WickedShelby88]

I plan on running a manual rack and cutting out the factory k fram section that the rack bolts to and welding in some square tubing to try to get some more clearance.

[Clay]

So far, the 52mm t/b seems to make the most power on our 8 valve engines, 16 valves is another ball game.

I thought the 52mm TB was didnt seem to help much, and actually gave worse gas mileage?

[moparzrule]

On a daily driver, the 52mm gives more less throttle response and more lag and you need to have a good flowing setup to justify a 52mm TB. But on a street/strip car, non DD, the 52 gives more power. And yes people usually see worse fuel mileage too.