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Anybody using Southways 108mm TB?? Having problems with it
C6 Corvette ZR1 & Z06General info about GM’s Corvette Supercar, LS9 Corvette Technical Info, Performance Upgrades, Suspension Setup for Street or Track
Anybody using Southways 108mm TB?? Having problems with it
I installed a Southways 108mm TB and lost 50rwhp on my 468ci LS7. When we pull the car on the dyno and let off it goes into reduce power mode. Do you think the throttlebody plate is shutting closed because maybe the motor is not strong enough to keep it open. It has a brand new OEM motor. Someone was mentioning maybe changing the voltage through the tune to the throttlebody. I think Monday we’re going to put the NW102 back on and see. I just don’t see how I should lose power especially a big cube motor that needs air.
When it comes to porting, bigger does not necessarily mean more air. Just hogging out runners doesn't mean you are now getting more air. Just like when Richard@WCCH told Josh he can open up the heads for his new intake, but it will hurt flow and power. Hopefully it is just a TB issue with it not opening fully, but as long as it is wide open at WOT, next thing to do would be go back to the old intake.
Sorry to hear that you are having all of these problems. It is clear to me that it is not easy or cost effective to go from a well thought out LS7 with 630/640whp to 700whp. I don't even want to ask the amount of money that you have put into this motor but it has to be substantial. To me, it would certainly be easier and cheaper to build a lower compression motor and boost it or just stay at the 630whp range.
However, I do understand the rational of having a high revving NA motor, but I am not sure that benefits outweigh the costs.
I don't daily my Z, but I do have a handful of German cars that are boosted and there is no question in my mind that FI on a daily driver is that way it should be.
When it comes to porting, bigger does not necessarily mean more air. Just hogging out runners doesn't mean you are now getting more air. Just like when Richard@WCCH told Josh he can open up the heads for his new intake, but it will hurt flow and power. Hopefully it is just a TB issue with it not opening fully, but as long as it is wide open at WOT, next thing to do would be go back to the old intake.
I would think something has to be going on if it goes in to reduce power or limp mode
Sorry to hear that you are having all of these problems. It is clear to me that it is not easy or cost effective to go from a well thought out LS7 with 630/640whp to 700whp. I don't even want to ask the amount of money that you have put into this motor but it has to be substantial. To me, it would certainly be easier and cheaper to build a lower compression motor and boost it or just stay at the 630whp range.
However, I do understand the rational of having a high revving NA motor, but I am not sure that benefits outweigh the costs.
I don't daily my Z, but I do have a handful of German cars that are boosted and there is no question in my mind that FI on a daily driver is that way it should be.
If nothing works I’ll just go back to my old set up and be happy with 680rwhp n/a.
When it comes to porting, bigger does not necessarily mean more air. Just hogging out runners doesn't mean you are now getting more air. Just like when Richard@WCCH told Josh he can open up the heads for his new intake, but it will hurt flow and power. Hopefully it is just a TB issue with it not opening fully, but as long as it is wide open at WOT, next thing to do would be go back to the old intake.
I think what we are going to do is install the NW102 back on and have a apples to apples comparison. And just compare intake to intake
Good idea. Hopefully that was it because it would be sad if you paid someone to ruin your intake. I wouldn't have touched it before, so hopefully it was something else.
I would 100% go back to the NW102 and see what happens. Pushing that kind of power you shouldn't drop HP with Tony's MSD. I would definitely say it's the TB. Good Luck!
If nothing works I’ll just go back to my old set up and be happy with 680rwhp n/a.
It would sure be nice if someone else with a 108 would let you borrow theirs.....if I had one I'd sure let you try it out just to compare.....I know how frustrating these things are!
Don't give up just yet, that motor has a hell of a lot more power in it just waiting to be tapped!!!
I let Jason @ TSP borrow my 108TB for testing. He saw ~5HP gains over a 105mm TB on a max effort LS3. He only saw ~3HP from 102mm to 105mm. That was on an engine dyno.
Bigger isn't always better. I could easily see the MSD being ported like that and lose power.
I agree with your statement but I don't think there is enough meat in the runner thickness where you could remove enough material that the ~7% larger displacement engine would drop peak 50hp by opening up the runners a bit more. I do realize the new ported shape of the runners are probably less efficient than originally ported by Mamo and that could account for some difference. Tony does a great job of keeping port velocities high at lower rpms ranges without sacrificing high rpm flow giving a great power curve. I would guess some of that could be lost with home porting unless you really study where to remove material.
I agree with your statement but I don't think there is enough meat in the runner thickness where you could remove enough material that the ~7% larger displacement engine would drop peak 50hp by opening up the runners a bit more. I do realize the new ported shape of the runners are probably less efficient than originally ported by Mamo and that could account for some difference. Tony does a great job of keeping port velocities high at lower rpms ranges without sacrificing high rpm flow giving a great power curve. I would guess some of that could be lost with home porting unless you really study where to remove material.
Agreed, just pointing out that paying someone with a die grinder to go ape **** on your intake to open everything up, probably wasn't a good idea, and probably hurt performance more than helped.
Sounds like the inlet isn't ported enough and the throttle blade isn't opening all the way.
This, the MSD is only open 102mm I think. You would have to port a ton out of the opening. Pull the intake back apart and mount the 108 to the opening to see if it does hit when you open the blade.
Agreed, just pointing out that paying someone with a die grinder to go ape **** on your intake to open everything up, probably wasn't a good idea, and probably hurt performance more than helped.
I agree with you BUT Tony isn't just any guy with a die grinder. I have never heard of someone losing HP with one of his ported MSD's. He knows what he is doing and puts a lot of time in R&D. Just my 2 cents!
This, the MSD is only open 102mm I think. You would have to port a ton out of the opening. Pull the intake back apart and mount the 108 to the opening to see if it does hit when you open the blade.
The 108 comes with an adapter that must be used when bolting on to a traditional 4 bolt throttle body flange, as the Southways unit uses 8 bolts. This effectively spaces the 108 tb further away from the mouth of the intake
Originally Posted by C6Z06Silverbullet
I agree with you BUT Tony isn't just any guy with a die grinder. I have never heard of someone losing HP with one of his ported MSD's. He knows what he is doing and puts a lot of time in R&D. Just my 2 cents!
This new MSD intake he is trying is not a stock Mamo ported MSD. It has been extensively modified by another "porter"
The 108 comes with an adapter that must be used when bolting on to a traditional 4 bolt throttle body flange, as the Southways unit uses 8 bolts. This effectively spaces the 108 tb further away from the mouth of the intake
This new MSD intake he is trying is not a stock Mamo ported MSD. It has been extensively modified by another "porter"
Thanks you for the info, I was unaware that someone else had there hands on it!
01-25-2019, 11:33 PM
Anybody using Southways 108mm TB?? Having problems with it
