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rdnoel86
10-23-2009, 09:37 PM
I'm doing some extensive manifold mods...along the lines of DCR's twin set up with a couple twists. I have a couple questions before I finish it up.

Is replacing the internal wga with an external unit that benificial?? I know I can do some more porting work with it gone to create some more flow.

If so, which is the best route?, Ive seen two methods to accomplish this, one is by running a pipe to the O2 housing and the other basicly reroutes itself back into the exhaust manifold. Does it really matter? Thanx...

contraption22
10-27-2009, 11:18 PM
I'm not trying to discourage you from trying something different, but you do know you can get a T3 flanged manifold for these engines fairly cheap, right?

Keito
10-28-2009, 08:03 AM
I'm not trying to discourage you from trying something different, but you do know you can get a T3 flanged manifold for these engines fairly cheap, right?

Not if he's trying to run twins.


Go to SRT Forums, in the vendor section Realtune has dynos with
an external wastegate setup.
It does show gains.
They have also stated that porting the stock manifold too far reduces velocity.

Also saw a post a few years ago, someone had an external setup
and rerouted it back to the exhaust and lost HP.

These are just observations I've had over the years, I'm not saying they are
true. With a twin setup, obviously results will be different.

rdnoel86
10-30-2009, 06:23 AM
Thanx...I'll check it out. :thumb: I think I'm going to order injectors from realtune anyway..maybe I'll quiz them:nod: I know this might not be the most efficient route to take but the I just think its a cool set up. I had my own ideas then DCR came out with something simular to what I was thinking so I'm trying to incorporate the best of both into one project. And really the cost is minimal...I have 5 manifolds sitting around that I paid around 20.00 a peice for and I have 4 turbo's that I have under 50.00 each into. One is brand new. So basically I'll have 150.00 into it plus my time.....I was going to buy one from DCR....but I couldn't pull the trigger on a grand for just the manifold when I could do my own and put my own twist on it......




Not if he's trying to run twins.


Go to SRT Forums, in the vendor section Realtune has dynos with
an external wastegate setup.
It does show gains.
They have also stated that porting the stock manifold too far reduces velocity.

Also saw a post a few years ago, someone had an external setup
and rerouted it back to the exhaust and lost HP.

These are just observations I've had over the years, I'm not saying they are
true. With a twin setup, obviously results will be different.

turboshad
10-30-2009, 10:50 AM
I'm not trying to discourage because I don't think it is my place but a local guy tried twins and it didn't work well at all. He had large problems with surge and couldn't get any serious boost until mid to upper 4 grand. Here is the SRT4forums thread on his build.

http://www.srtforums.com/forums/f24/custom-twin-turbo-setup-pics-499531/

Here is a really good quote from that thread.....


We talked with Dave Andrews at Garrett Engine Boosting Systems who is an application engineer that's had considerable experience designing race-only turbos of a wide variety of race applications. His reponse is as follows"

"There is currently a myth that multiple turbos are inherently better than a single turbo when it relates to gasoline turbocharging," Dave said. "This simply isn't true. A large single turbo is always more efficient than multiple smaller units. The increased turbocharger efficiency afforded by larger units results in less backpressure, lower intake manifold temperatures and often better transient response. As turbochargers increase in size, they become more efficient. In the case of the centrifugal compressor wheel, as the wheel diameter gets larger, the blades experience less back-flow due to favorable wheel/housing tip clearances. The turbine wheel shares the same benefits when run in larger diameters. These increases in compressor and turbine efficiency produce a higher overall turbo efficiency."

"The actual differences between single and twin turbos as it relates to horsepower can be significant" he continued. "For example, on a 400-cid pro 5.0 engine, a well matched single turbo can create the same boost pressure as twins, but with 12psi lower exhaust manifold pressure. The lower exhaust pressure results in lower engine pumping losses and a slight increase in volumetric efficiency. In addition, the single turbo will operate at a higher compressor efficiency. This has two effects less turbine power required (lower backpressure) and lower intake manifold temperature. It's very possible to see 40 degrees or lower compressor outlet temperatures from a good single turbo versus smaller twins. This translates into a cooler, denser intake manifold charge. Comparing a large turbo compressor map to a smaller unit with half the flow capability will immediately show the difference in compressor efficiency at a given pressure ratio."

"I only know of two situations where multiple turbos are better suited," Dave said in closing. "The first situation relates to high boost diesel turbocharging where the user needs boost pressures over 60psi. Competitive tractor pull vehicles often use multiple turbos. In this case, series turbocharging (where one compressor feeds into another compressor) works much better than a single unit in building ultra high boost levels. Another example of series turbocharging is on high altitude aircraft. The current record holding aircraft for high altitude climbing uses two (and sometimes three) turbochargers in series to make up for low air pressure at altitude. In both of these examples the user requires a pressure ratio in excess of 51 whereas nearly all gasoline powered racing bodies run below 31 pressure ratio (less than 30psi of boost)."




EDIT: I just noticed I started my post the same as contraption22............that was http://image.srtforums.com/srtforums/images/smilies/outofcloset.gif

rdnoel86
10-30-2009, 07:11 PM
Ahhh...discourage away.....as long as its with a valid thought process and not just bashing I can use the info to to help me along. I'm pretty hard headed once I get an idea that I think will work...even if it is off the beaten path...and there have been a couple twin set ups that have worked good....like I said, I know its not the most efficient method around......but if we were all after that, we wouldn't be playing with turbo-mopars now would we???:eyebrows::thumb: