I would be reluctant to say that any exhaust system will actually make horsepower. they may not restrict as much as others but that is different than actually making hp.

 

I liked the 68 factory cover look but did not want to spend the money for factory covers.. nor the power robbing stock muffler system. I had some Ecklers side pipe covers vacuum metalized and clear coated to look like chrome.. then used a set of headman side pipe headers, some 3in tube from Summit, stainless turnouts from Edelbrock and STS uncapped "hot rod" baffles (the hotrod baffles are only 12in long). I adapeted the factory side pipe hangers to work with the clamps that hold the turnouts on. It is by no means quiet. Idles about as loud as my F350 diesel with a flowmaster exhaust. The 427 sounds fantastic thru these @ 6500..
-F

 

That's the way to do it if you want the factory look!

I like it!

 

I like . . . two thumbs up!

 

Really? Do you have "real" numbers to prove this?

Oh, I guess you don't.

 

I have read a ton of side pipe post available on this forum, both current and archive. After reading many posts it is usually between STS and Hooker Max Flo (the Sweet Thunder, while a quality product, seems to offer no advantages over the STS or Max Flo).

I have come to the following conclusions. Please correct me where my assumptions are in error.

Hooker Quiet side pipes:
The Quietest and the most restrictive

Hooker Glass Pak:
Louder and less restrictive

Sweet-Thunder 2” insert:
Similar to above

Sweet-Thunder 2.25” insert:
Louder and less restrictive than 2”

Sweet-Thunder 2.5” insert
Louder and less restrictive than 2.25

Spiral Turbo Baffles (undrilled)
About the same a the 2.5 above

Hooker 4” Max Flow:
Louder and less restrictive than above

Spiral Turbo Baffles (drilled):
Louder and less restrictive than Max Flow

Open Tubes:
Loudest and least restrictive


Anyway, you mentioned you would like numbers . Check out the data from a dyno run in a post from ZL1powr. Here is the link. Be sure to click also click on the Video of dyno runs

http://forums.corvetteforum.com/c3-t...-carlisle.html

Hope this helps.

 

Yes, they are assumptions.

HTTP 404

 

Think he was referring to this post:
http://forums.corvetteforum.com/c3-t...-carlisle.html

 

I've read that thread before. Actually, that thread is what made me dicide to buy my Max-Flo's.

 

That looks fantastic. I have been debating on doing something like that, or go with XS Power or Hooker sidepipes. Your setup certainly looks like it would be the most cost effective solution, and the fiberglass covers should keep things fairly cool to prevent leg burns. Where did you get the Ecklers side pipe covers vacuum metalized and clear coated to look like chrome? How much did that cost you to have done? I am assuming that these are the fiberglass covers, or are they the metal reproductions? Again, nice setup, thanks!

 

Actually I don't have "real" numbers and it would have been more acurate to say "based on what has been posted on this forum it seems that uncapped STS baffles offer the least power loss". When you do a search in this forum using "baffles" there is lots of reading and many of those threads have dyno numbers for STS baffles. Here's one http://forums.corvetteforum.com/c3-t...vs-spiral.html I thought it would be easier to decide which insert suits you/your car best if the 3 major players were tested on the same 500+ horsepower motor with a sound clip so you could weigh the pros and cons of both. I'm leaning towards Max-Flo's also.

 

Thanks. They will say they stay cool for sure.. and they are very light weight. It was some work to make sure the pipes don't touch the covers anywhere. You should be able to fit pipes/mufflers up to around 3.5 in under them without touching. The cost of the chroming process was around $550 with another $150 to clear coat them for durability.. so when you consider the the cost of the covers themselves and shipping to the plater.. it's around $1k.. you may be able to find real covers on flee bay for that. You also need to take time to prep the covers, as any imperfections will show thru the plating as it is very thin. You can contact Tony Azcue @ Tony's Auto Classics - Dallas TX for the plating - (shelby1968@tx.rr.com).

 

I have hooker headers and side pipes with both glasspack(great deal from a friend) and the max flows. I personally like the glass pack sound better, but feel they are really robbing my 500hp 406. Not sure if it was all the max flows or the cooler winter weather, but the car is way different with the max flows, very strong. They are real loud though, even the neighbor that likes me threatened to call the noise police. Since I have both I think I will run the glass packs unless I am going racing, takes me a bout 30 minutes to swap them out, but I have yet to re-install my rocker moldings.
I also have a hi pitched chirp out my passenger side with the max-flows that I put started a post on last week. Still not sure what that is.

 

I too think that the Max flos are a bit too loud, but the glasspacks would really strangle my 502.

When I bought my '69 in 1979 it had a '70 LT-1 motor and sidepipes with glasspacks. One day I removed the side tubes and took it for a ride. What a difference! It had to have gained 50 hp, and this was only 350 cid. With glass packs on, the motor would quit pulling at 6000 rpm. Without the side tubes it was still pulling at 7200 rpm. Of course max flos didn't exist then.

The chirp is probably the insert moving around slightly.

 

Me too. Unfortunately they will too loud for most track events requiring a car with mufflers.

 

The quickest way to boost hp on a pre computerized small block Chevy motor is to free up the breathing on both the intake and exhaust sides as the heads were much better at air flow than the stock (iron) manifolds would allow. This has been proven in countless magazine articals over the past 50 years. If you go by mfg. hp numbers an alum intake and most any header will make more hp/torque than their cast iron brethern. If you believe that the hp was always there waiting to be unleashed.....you say tomato, I say tomotto.

Compare Hookers with 2 90* bends per pipe vs Stahls with none save the 4" one that points the gases down the side of the car, I don't think an engineering degree is required to say that the Stahls are less restrictive freeing up more hp/torque to the rear wheels. There are some under car headers that might show more gains, but to tie them in to side exhaust usually results in a big S pipe and that will take away any efficency you might have picked up. Is a high lift cam less restrictive than a stock one? Are aluminum tall runner angle plug heads less restrictive than stock iron ones? You go faster by doing one of two things, remove weight (anywhere you can) or make your motor more efficent (by removing restrictions). More hp to the rear wheels has and still is what it's all about. /:\

 

I just gott'a ask....... are you guys replacing header gaskets a lot with these fenderwell headers? Seems a lot of leverage and twisting might be unavoidable with them.

 

Never had to.

 

 

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