PROPOSED GROUP BUY: S & S headers group buy

[Imdone]

Originally posted by Verndog
Imdone

I checked out the pic on new S&S headers. It is possible they could fit my new dual with very little work. Could you give me a distance center to center of the Y pipe (center of left tube to center of right tube), and then the length of the straight section of Y pipe (flange face to flange face). It looks close to same as stock Y pipe and if it is .....I'm in like Flynn!!

Kevin

I can't give you measurements yet, I don't have a set. When I get them I will post that I have them and anyone with duals can ask for measurements. I will get and post them.

[Imdone]

Originally posted by TMS2U
Those are some purdy pipes!!!!

I know you like 'em.

[KLS]

Originally posted by Imdone
READ THIS!!!

It has been brough to my attention that there has been some confusion of pricing here.

The group buy ONLY is $799 + $20 shipping for a total of $819.00 to your door.
........

Thank you.

And, "S&S' shipping rate for the headers to most parts of the U.S. via UPS ground is $20." So, the shipping cost might be a bit different. In any case, you'll get the exact total cost direct from S&S before you pay.


Ken

[arkie6]

I have a concern with these S&S headers and that is the use of 1-5/8" primaries instead of 1-1/2" primaries. Anybody else have this concern? I would have preferred to have seen 1-1/2" primary tubes with 2" or 2-1/4" collectors. Or 1-1/2" primaries stepped up to 1-5/8" or 1-3/4" at the Tri-Y, then stepped up to 2" or 2-1/4" at the collector.

In theory, the smaller diameter primary tubes and collector should improve performance at lower RPMs moreso than the larger primary tubes, and that is what I am looking for.

I think we are seeing some of these effects when comparing the JBA Headers (1-1/2" primary tubes) against the JBA copy headers from SSAutochrome (1-5/8" primary tubes). From what I have read so far on here, those with the JBA's seem more pleased with the torque improvement in the lower RPMs than those with the ebay knockoff headers with larger primary tubes.

I guess I'll wait and see what the dyno results are before I put any money into these things, although it is nearly impossible to get a dyno plot with an automatic transmission where it matters to me - in the 1500-3500 RPM range. About the only way to get that info is to do before and after dyno runs in 1st gear to keep the transmission from shifting down under WOT. Or has anyone figured out a way to fool the ECU into not shifting the transmission down under WOT?

Are any dyno tests even planned with before and after results?

By the way, here is a link to the S&S Tundra headers including the picture of the prototypes >>> https://ssl5.mysecureserver.com/boss...?idproduct=558

[KLS]

Arkie,

I had the same thoughts, but checked the header bible, "Scientific Design of Exhaust & Intake Systems, Third Edition," Smith & Morrison, Bentley Publishers.

They say, "The diameter of the primary pipes should be based on the dimensions of the valve throughway.... The valve throat diameter (below the valve) should be measured.... To allow for boundary friction in the pipe, its internal diameter should be slightly greater than the valve throat diameter [at least 1/8" larger]." pp. 142.

So, according to Loren, the 1-5/8" primaries are a good match for the exhaust port and presumably for the valve throat ( not the valve size). That valve throat size isn't in the books, and I don't know of anyone having a head around to measure.


Ken

[Imdone]

I have decided that I will "attempt" to get a before dyno run. I will also get an after dyno run.

The real test is going to be towing the boat up a 6+% grade.

I have set up a test that I will do before and after. I plan to have results after all has been installed and tested. I will have the exact weight of the boat and rpm shifting and maintainable speed without having to shift. This will give an actual measure of where the torque pull is.

The breakdown will give all figures. Weight, grade, speed maintained, gear traveled in, shifting, rpms maintained and time to get from bottom to top.

I will post it here. This will be before and after.

This will be the real torque test and to see if we achieved the targeted rpm range.

Arkie6,

Your point is exactly why a Dyno test is not going to excite me. It does not really suit what we are trying to do with an auto tranny. I am going to try to find a local dyno shop and explain what I am trying to acheive, hopefully I can get some assistance. We will see.

[Dude Boy]

So, according to Loren, the 1-5/8" primaries are a good match for the exhaust port and presumably for the valve throat ( not the valve size). That valve throat size isn't in the books, and I don't know of anyone having a head around to measure.

I could stick my fingers in there far enough to verify there were two exhaust valves! I can't remember how close to the gasket size that the ports are, but I have a new set of gaskets in the garage if you want me to measure them. I think the 1 1/2" size is the best, just because of what works on Chevies and the motor is about the size of a 283. I doubt that anyone will ever be able to prove that any of these headers are better than the others with so many variables. It's not even likely to positively prove one catback system better than the others. It's easier to screw things up and make them worse by modifying than it is to make them better. I do know of several who have made over 220 HP on the dyno with JBA's and duals. The magazine article that featured the Tundra TRD header install showed 232 HP.

[arkie6]

Originally posted by Dude Boy
...I can't remember how close to the gasket size that the ports are, but I have a new set of gaskets in the garage if you want me to measure them.

Yes, please. And do you still have that cracked OE exhaust manifold? If you do, could you measure the ID/OD of the cylinder ports on that manifold and post them here?

[KLS]

Originally posted by Dude Boy

....
I do know of several who have made over 220 HP on the dyno with JBA's and duals. The magazine article that featured the Tundra TRD header install showed 232 HP.

I'm not interested in peak hp. I'm only interested in improving power in the rpm range I drive at, usually 1800-3000, and occasionally 4000-4500. I don't want to hurt peak hp, but what I really want is a fatter hp curve in the mid range.


Ken

[Imdone]

A minor detail that could answer the pipe size discussion here.

These are coated headers INSIDE and out. I don't know what the coating thickness is but I am sure that from a mild steel 1 5/8" pipe it will reduce the I.D. of the pipe with the coating.

Maybe this is some of the reason that S & S did it this way.


:Edit:

I couldn't find a thickness on jethots web page.

Does anyone know if the thickness could be a factor? This was more of a statement question.

[Dude Boy]

Yes, please. And do you still have that cracked OE exhaust manifold? If you do, could you measure the ID/OD of the cylinder ports on that manifold and post them here?

I don't have the cracked one, but I have a set of brand new ones! I'll measure them and post later this evening. Ken, I don't think the dyno's on the other duals and headers I spoke of showed too much of a problem at the lower revs. It's pretty hard to get the engine to pull with any throttle applied below about 2700-2800 RPM anyway isn't it? Mine just forces a downshift and gets right into where the real power resides. I don't think you can get a whole lot down low out of a 4 valve engine without VVT. Mine either runs at 1400-2000 RPM most of the time, or at 4000-5000. The automatic doesn't give you a whole lot of choice. It would sure be nice if it didn't downshift when in manual 2nd, wouldn't it?

[Dude Boy]

I can't remember how close to the gasket size that the ports are, but I have a new set of gaskets in the garage if you want me to measure them.

The opening in the gasket is a bit under 1 3/4" but it is designed to fit the reinforcing flanges that are welded onto the manifold tubes. I remember the ports in the heads being quite a bit smaller because there was quite a lot of carbon build up to clean off on the head surface between the gasket contact area and the port opening. I've attached a picture of the gasket measurement.

[Dude Boy]

Here's a picture showing the outside diameter of one of the manifold tubes measured just below the reinforcing flange. It's pretty close to 1 1/2" OD and appears to be about 16 gauge which is approximately 1/16" inch wall thickness.

[Dude Boy]

Here's a picture showing that the inside diameter is pretty small. In this picture, I have set a socket measuring 1 9/32" in diameter into one of the manifold tubes. It only dropped in about halfway. This is in the front tube which seems a bit smaller than the others because of the swaging used to make the bend. The other tubes are pretty close to 1 3/8" or maybe just a hair smaller.

[Dude Boy]

This picture shows the inside diameter of the reinforcing flange just above the point where it's welded to the tubing. It's pretty close to 1 1/2" there.