SC Top tech talk

Regul8r

Regul8r

Registered User
have watched alot of different ideas for SC Tops.

1. Raised plates to make a full round outlet tube instead of the stock crimped area.
2. Custom made ones to redirect the direction the outle is for custom FMIC tube routing
3. A whole slew of different raised tops of all different designs

The V of the SC is alot bigger than the tubing and the lower intake inlet port.

Does the space on top of the SC cause any problems with flow or a large cavity issue? we work hard to smoothe the flow everywhere in the system to include using air deflectors/splitters in the IC's or using a straight through FMIC, not using a same side in/out IC

With the silencers sealed off the only air coming out would be through the "V"
The airflow is pushed from back to front and pushed out the "V" directly up and forward against the front edge of the SC Top.

When building a custom SC Top(Silencers closed), would it be worth it or could it be helpful to somehow have the top "Seal" down inside the SC around the "V" and smoothe transition to round IC Tubing? Theoretically make the flow smoothe from blower into the piping at about the same size as the "V" (3" tubing)?

Further thinking of making the outlet facing direct forward to maximize the flow (no change of direction out the "V"). Smoothe the flow over the front edge of the SC outlet area just as is done to the heads and the big sharp point in the exhaust ports?

Tech discussion here... thoughts, ideas, theories, or other opinions on this?
 
Regul8r said:
have watched alot of different ideas for SC Tops.

1. Raised plates to make a full round outlet tube instead of the stock crimped area.
2. Custom made ones to redirect the direction the outle is for custom FMIC tube routing
3. A whole slew of different raised tops of all different designs

The V of the SC is alot bigger than the tubing and the lower intake inlet port.

Does the space on top of the SC cause any problems with flow or a large cavity issue? we work hard to smoothe the flow everywhere in the system to include using air deflectors/splitters in the IC's or using a straight through FMIC, not using a same side in/out IC

With the silencers sealed off the only air coming out would be through the "V"
The airflow is pushed from back to front and pushed out the "V" directly up and forward against the front edge of the SC Top.

When building a custom SC Top(Silencers closed), would it be worth it or could it be helpful to somehow have the top "Seal" down inside the SC around the "V" and smoothe transition to round IC Tubing? Theoretically make the flow smoothe from blower into the piping at about the same size as the "V" (3" tubing)?

Further thinking of making the outlet facing direct forward to maximize the flow (no change of direction out the "V"). Smoothe the flow over the front edge of the SC outlet area just as is done to the heads and the big sharp point in the exhaust ports?

Tech discussion here... thoughts, ideas, theories, or other opinions on this?
Click to expand...

Front facing can cause a problem with hood clearance. There been many diffrent custom tops made for individual unique setups but the top just seems to have never shown promise for performance, least wise on the dyno. Look at the cost of the offerings out there now and with zero improvement on a dyno that like 300+ bucks for something that looks good but doesnt add anything performance wise. The majority have to have a bolt on top that fits stock tube, we already have a bolt on performance top out there for that. Most people arent going to have the needed skills to run custom pipes and one off type work take time to fit and build correctly and look good and that doesnt help the rank and file. Also keep in mind that a top built just right to obtain the best possible flow would be expensive. I look at the price of the raised top offered now and think I should have gone into the business of building raised tops vs Intercoolers.


KEN
 
Most use 2.5 or 2.75 tubing, I can only think of a couple using 3". 3" is some big tube and you may have trouble getting it to fit depending on what your IC is.
 
Regul8r said:
What are the pros/cons of IC tubing size?
2.5" or 3"?
Click to expand...

The 3" is more than anyone really needs. I upgraded to 3" for several reasons. One, Dave told me the 2.3 whipple was best setup with 4" intake and 3" out flow. I have yet to upgrade to a 4" intake (I just upgraded to the 3.5" last year) BUT I have a big blower capable of using 3" to an advantage. My guess is:rolleyes:for a M90 blower is that the 3" is to big and not a plus and maybe a negative for the smaller blower. As an example, when I had a stock internal engine, a M90 blower, 10% overdrive and other bolt on mods. I enlarged the return plenum and the lower intake inlet quite a bit, including polishing and porting the lower intake. Gain on the dyno was a fat zero. Going bigger isnt always better if you dont have the rest of the package up to specs. 3" tubes look cool but I dont beleive they do anything performance wise unless you have a lot of blower to back them up. And yes they are a bitch to fit in available space. But they look COOL. Anyway my opinion;)

Ken
 
rzimmerl said:
Most use 2.5 or 2.75 tubing, I can only think of a couple using 3". 3" is some big tube and you may have trouble getting it to fit depending on what your IC is.
Click to expand...

Sorry, let me clear up my question...

The "V" outlet of the SC is bigger than 2.5" so if so much air is being forced out the SC into the tubes then why not make the whole system the same size so it all flows at the same capacity? This with the SC Top sealed to "port match" the SC "V" outlet as said in first thread.

Outlet of SC(bigger than 3" round area), 3" IC tubing, 3" FMIC would make for smooth unrestricted flow? The Lower intake plenum inlet and inlet tube is the one spot that is smaller and almost un fixable without ALOT fabrication. This area requires extensive Aluminum welding and fabrication ability.


Is there any REAL reason not to make the SC Top extend downward to port match/seal to the "V"?
Am I off base with my thinking?
 
kenewagner said:
The 3" is more than anyone really needs. I upgraded to 3" for several reasons. One, Dave told me the 2.3 whipple was best setup with 4" intake and 3" out flow. I have yet to upgrade to a 4" intake (I just upgraded to the 3.5" last year) BUT I have a big blower capable of using 3" to an advantage. My guess is:rolleyes:for a M90 blower is that the 3" is to big and not a plus and maybe a negative for the smaller blower. As an example, when I had a stock internal engine, a M90 blower, 10% overdrive and other bolt on mods. I enlarged the return plenum and the lower intake inlet quite a bit, including polishing and porting the lower intake. Gain on the dyno was a fat zero. Going bigger isnt always better if you dont have the rest of the package up to specs. 3" tubes look cool but I dont beleive they do anything performance wise unless you have a lot of blower to back them up. And yes they are a bitch to fit in available space. But they look COOL. Anyway my opinion;)

Ken
Click to expand...

Thanks Ken.

Maybe I am asking this different and need to change my approach to this?
Do I need to think more along CFMs?
I read somewhere the stock IC is a major restriction at only around 240cfm?
the rest of the system flows around 450cfm?

So IF the CAI with 75mm MAF/TB flow XXXcfm, the Inlet plenum flows XXXcfm, the SC sucks XXXcfm and blows XXXcfm, wouldn't you want the IC and tubing to also be capable of flowing the same XXXcfm the SC blows? Thought is to make all parts capable of flowing the same XXXcfm? Remove the restriction just like we do when porting the Exhaust manifolds and removing the resonator?

I understand what your saying about the size of tubing being too big... there has to be a perfect size for optimal flow? probably the 2.75"?
 
I think what you are trying to do is beat a dead horse:cool:. The square bolt on top in any configuration has been shown to give minimal gains to those with lots of bolt on parts making some power, and moreless pointless bolt on to an otherwise stock motor. I believe no matter what you do your going to get the same result, there is no magic here to unleash massive amounts of horsepower. If your having a custom SC top made to need to know how your are going to hook up to your IC tubes, and more importantly how will it fit under the hood you decided to go with. Not much will fit besides an MP like top with the outlet angled like it is under a stock early model hood.
 
Regul8r said:
Thanks Ken.

Maybe I am asking this different and need to change my approach to this?
Do I need to think more along CFMs?
I read somewhere the stock IC is a major restriction at only around 240cfm?
the rest of the system flows around 450cfm?

So IF the CAI with 75mm MAF/TB flow XXXcfm, the Inlet plenum flows XXXcfm, the SC sucks XXXcfm and blows XXXcfm, wouldn't you want the IC and tubing to also be capable of flowing the same XXXcfm the SC blows? Thought is to make all parts capable of flowing the same XXXcfm? Remove the restriction just like we do when porting the Exhaust manifolds and removing the resonator?

I understand what your saying about the size of tubing being too big... there has to be a perfect size for optimal flow? probably the 2.75"?
Click to expand...

There just a lot of factors involved. If you have a stock IC you will have restriction if you are trying to move more air, that being a diffrent discussion . You can always improve on air flow, and some things seem to be more important than others. Designing a top diffrently to improve the air flow or increase the air flow isnt bad but the return on you sweat equity and materials dont equate to HP. Is spending lots of time and money worth maybe 5HP? The raised top offered now shows no increase on a stock or slightly warmed over engine. Like Ryan said the top is not one of the important mods, now get over 400 HP and it might become more important but then all the over 400 HP cars are twin screws (we wont count turbos) and their tops are bigger than a M90 top.

Ken
 
To add to Ken's comments, the AR outlet is smaller then the M90 V outlet shape (would have to calculate the area to be certain). I am using a Magnum Powers top with a custom AR adapter plate.
 

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See We are all over teh place on this. Back in the day dyno tests had shown the various tops making various HP and TQ increases....Then some say none...

So what is it? Believe this one or that one..Bottom line is the factory top looks like crap from a flow restriction standpoint
 
The air exiting the V of the supercharger is very turbulent and comes out in pulses. These pulses are strong enough to break welds on sheet metal fabricated tops and will also break off a difusser welded inside the top (ESM raised top) intended to straighten out the air flow. I'm not sure if it's air pressure pulses or sound waves that cause the damage.

The raised top offered by Magnum Powers appears to do as good of a job as any fabricated top I've ever seen. Not sure if funneling the air directly from the V into the IC tube would help or hurt. I would expect curved surfaces inside the top to perform better than sharp angles that some sheet metal tops have, but on the dyno or track it doesn't seem to matter how it's constructed. The inside of the MP and stock top include some directional vanes/ribs cast into the inner surface that are likely intended to help direct the air exiting the supercharger.

As others have already indicated, there doesn't seem to be much gains possible in that area, so I wouldn't spend a great deal of time on it. On the IC tubes, I think 3.00 is more than enough and 2.75 is probably the best as far as fitment and flow. Since 2.75" is not a common size for tubes or silicone couplers, most people will use 2.5" or 3.0" tubing.

David
 
David Neibert said:
Since 2.75" is not a common size for tubes or silicone couplers, most people will use 2.5" or 3.0" tubing.

David
Click to expand...

I guess since I am not most people, I use 2.75" pipes, couplers and the FMIC even has 2.75" inlet and outlet.
Hmmm ........ and the front outlet top I am using, even has a 2.75" oulet. :cool:
 
XxSlowpokexX said:
See We are all over teh place on this. Back in the day dyno tests had shown the various tops making various HP and TQ increases....Then some say none...

So what is it? Believe this one or that one..Bottom line is the factory top looks like crap from a flow restriction standpoint
Click to expand...

Can you find those old posts? I have been here for sometime now and have yet to see anyone posting gains on the dyno.

Ken
 
I recall back in 2002 ESM raised top with diffusers making 14rwhp on a modified motor. I also recall reading a comparison (maybe a rich thompson) on the MP, ESM and like two other tops...Thsi was a long time ago..But you can find posts with mention of the ESM numbers and MP numbers. As far as actual dyno sheets..Nope
 
XxSlowpokexX said:
I recall back in 2002 ESM raised top with diffusers making 14rwhp on a modified motor. I also recall reading a comparison (maybe a rich thompson) on the MP, ESM and like two other tops...Thsi was a long time ago..But you can find posts with mention of the ESM numbers and MP numbers. As far as actual dyno sheets..Nope
Click to expand...

Back when my car was running low 14s on a stock longblock with an ESM ported early blower and several other bolt on mods, Wade Embree (ESM) came to the track with one of his 1-1/4" raised tops with diffuser.

In between passes we swapped the MP raised top I had for his version and made another pass...it ran exactly the same ET afterward. But I did get a nice dent in the hood from the taller top hitting it. As soon as the MP FMIC came out (I was the 1st to buy one), I went back to the MP raised top and I'm still using it.

David
 
XxSlowpokexX said:
I recall back in 2002 ESM raised top with diffusers making 14rwhp on a modified motor.
Click to expand...

I can get a 14rwhp gain from farting in front of the air filter too. J/K :D

Nothing against ESM or anyone else, but the design impact of any type of SC outlet adapter on performance is simple. There is no ideal design and if you want to measure the effectiveness of your own design, just put a MAP sensor inside the top and one in your upper IC tube. If you measure a pressure difference, your top is insufficient. If you don't measure a difference or if your measured difference is less than .5psi or less, then don't worry about it. Otherwise all the guessing about what works or doesn't is just a waste of time and brain waves.

Don't over complicate it.
 
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