I'll try to post a couple of pics here....
I'm about as good a photographer as I am a speed typist.
Sorry about the size guys
These 1st two are of the left collector. The end of it is so close to the
bend in the floor that I can't bolt the "expander" to it.




Here's the left side smog hookup


The alt brace and anchor I made


That about does it for tonight guys. It's 3am and I'm hittin' the sack

 

The sets look the same length to me?

I measure 30" between the end of the Extensions to the Rear Y Flange, nominal. This seems an abundant plenty, at least for me with a 14" long Cat.

In fact the outside to outside dimensions between the Collectors is the same as the O.-O. of 2-1/2" Pipe I took off [ 20" +. So the geometry is real close to the same [ 3" material notwithstanding!].

The only issue is the driver's side. I think all agree that the collector extension is not a usable part.

There are pre-bent back to back 45 degree off-sets available. Summit Racing PN 18701 for example. My guess is a look of Parts stores can get theses in 3" .

I priced the parts and pieces of a making this with pre-bent stuff. There is still cutting and welding to do, but the costs are $118.00 in parts and pieces from Summit.

Seems that a good exhaust shop should bend a 3" Y for $150.00 - $200.00?

Being fairly stupid this way, I'll probably try doing it myself.

TJM

 

All I can say is WOW, you guys have some awesome patience,,,

I don't feel so bad about the modification I did on my Hookers, I cut out the offending tubes from the Hookers and re-welded new tubes in place that cleared the problem spots.

The only good way to do this is to buy the headers with NO coating, re-weld new tubes in, then have them Jet Hot coated. It's just crazy that this has to be done at all......

Kudos to you guys!

 

Bob,

First of all.... very nice work on your installation. I couldn't figure out how your alt bracket would work from an earlier pic, but I'm impressed. It was well thought-out, the result is professional, and the color-match is even better! Well done.

I really appreciate the pic. One thing it might show -- that I hadn't thought of (from the other shots) is how close the header runs to the floorboard -- as it's running down the car. I see the metal shielding you made and it's looks like a good precaution. I can't tell if you left any air space behind the shielding, but maybe there's no room?

I also thought the driver's side was going to me more of a problem at the rear. Boy, was I wrong! That's close.

Steven,
It just soaked in that your pic shows the driver's side installed. Considering you had the biggest problem with clearance (on #2), I wonder how you accomplished that?

I really wish they'd angled these headers in more (as they run back). I can tell by the pics that it's to accomodate A4's. Foooey on that. I'd vote for a straighter shot to the rear of the car. That's less of a restriction -- especially for "race" headers. No one races auto's anyway right?!!!

(O.K., I don't have room to talk with my curvey sidepipes, but still....)

Now that I have that out of my system.... Hooking up to these ain't going to be the easiest task in the world. Since the collector connections aren't really usuable, the price of these goes up. If welding on to them is necessary, maintenance on things like starters, drivetrain, trannies probably get's harder. (may have to unbolt from manifold!)

I'm with LD85. You guys have great patience. I wish I was a welder and had the equip. Without that, I'm sure these could get pricey. But, the good news is they may boost torque quite a bit. Notice in the original thread what #'s were just posted. I thought hp would be higher too, but maybe that's decent for an '85?

Tom,
I looked at the S pipes you linked from Summit. They only thing those would be good for is parts to begin mods. We obviously need something that turns IMMEDIATELY as they exit the collectors. Those extend a few inches before turning.

I didn't understand your measurements either. Is 30" your estimated distance as you curve around and head to the rear axle? Or is it the distance in the center section you have to work with on cat/muffler install? On the collector spacing, are you saying you hardly have to alter the original "Y" pipe to connect? Are you going to use any collector or weld?

Thanks again Bob. I appreciate the time you took to take/post pics!

Gregg

Oh yeah.... Looks like "Bandit4142" got the "good" set. In the other thread, he says the installation was a breeze -- expect for one bolt. Geeeezzzz.

 

Thank you! I hope its all worth it...

Steven

 

Hi Gregg,

The photos I posted are the pass/side not the drivers side. The drivers side when in with no issues at all. The only problem will be the 2nd collector. However, I have an idea that may work. I was thinking about cutting off about 1/4" .

I can't wait to get back my other header!

Steven

 

Could one of you guys with the 1 3/4" headers please take some measurements for me? I'm seriously considering buying a set of these but I want to run some calculations to see how they will complement my in-progress 383/AFR 195/ported FIRST package.

I would like to get the following info if possible:

- Primary tube length and outside diameter (measured from header flange on head side to where the pipes enter the merge)

- Secondary tube length and outside diameter (measured from start of the merge to the start of the collector)

- Collector length (distance from where pipes enter to the mounting flange)

- Inside diameter of collector at flange

TIA

 

Beat to Fit - Paint to Match philosophy.

This is the how I did the Alt. brckt.. 1/4" studs into Spark loom harness holes. 1" standoffs and mild steel bracket, shaped and drilled to match the holes.

A little bending needed, but it fits well and does not look to bad.

A piece of 3/4" Rigid Steel Elec. conduit and a decent vise makes a good enough bender for mild steel rod.

I'm needing a longer front stud to get a lock washer under that front nut.



Another shot of Alt. brkt This is the stock L98 unit.




A/C brkt. at header connection.



Compressor end of the bracket.

I cut it and threaded the 1/2" rod with a 1/2"x 13 thread die. A plane 1/2" rod coupling added the 5/8" I needed to make it fit.

Again a vise and a piece of stout 3/4" pipe to tweek the bends. A little touch up and it works.

 

I meant the pass/side... oops! Still, isn't that the side that hits the control arm? How did you show pass/side mounting -- if there's no room to mount? (That was my orig question in my last post).

If you've already sent your header in, what's with cutting off 1/4"? You sent your pass/side in, right?

 

Gregg :

Your correct in your previous post. Cutting and welding required.

The collectors are 16-7/8" apart, center to center. [ 20" outside to outside of extensions].

The 30" I spoke of is from the mouths of the extensions back to the flange on the rear Y pipe [tailpipe].


I would not spring for Summits price, just to butcher them, but would get a local muffler guy to bend the 3" pipes in theses configurations.

8" between the 45 degree bends should do fine.

I am cutting about an 1-1/2" from the outside 45 degree radius at the collector extension end. Then after cutting off the 3'" portions of the Extensions, I will weld the mild steel over the 2-1/2 piece [ keeping what ever venturi that might be]

Once that's done and right, I'll probably pay a shop to Siamese them into a 3" ID slip fitter, them onto the cat.

Done. Should be $100.00 fix. Jet hot the mess and I'm out for under $200.00

SS would be more, and weldings to mild steel is problematical. May do that? Some worry about heat from SS though?

TJM

 

If you remember my post I had to hammer and dolly the #2 tube to get it to clear the a-arm. It clears-but with very little clearance. The way it is, is not acceptable. Even with a new motor mount I only would have about 1/4 inch clearance. If you are running a stock alignment setting it may work. When I ordered these I did mention to Brian that I use the car to road race. However, I did not tell him about the alignment setting.

The driver/side went in with no issues, other than the 2nd collector being very close to the floor. This will also have to be address (by me-not Brian).

Steven

 

I hope someone with 1 3/4" headers will post Todd's request for dimensions!

Todd's been a great help.... I was teasing earlier when I asked Bob if he was a PIA during his visit!

I think these headers could be just the ticket for his motocross beast.

 

Can anyone determine if the fllanges are actually unusable? Could you use the collector extensions -- if they were cutoff shorter?

If so, I'd have to think Bob's original comment about cutting the flanges off -- and going to slip-fit might be required. If I send mine back in for alteration/recoating, that would be the time to do it! So, the cuts were coated.

gp

 

Steven,

I tried to send you a pm but the system said your inbox was full, could you pm me? I have a couple of questions for you.

Thanks,

jeff

 

I have 1 header (driver/side) mounted. The other header was sent back to get reworked. I will try to do the driver/side. Give me a few days.

Steven

 

Hi Jeff, received your email. I will send you my number.

Steven

 

The only part usable is the Extension flange itself.

We are going to cut-off the 3" portion of the extensions and weld mild steel Over the 2-1/2" portions, landing on the flanges.

Trying to do it with manderel bends is problematical and costs much the same.

I am having a shop do the Y pipe. $130.00 plus what ever nit picking costs me. If it's under $175.00 then I would say it is cost affective.

I'm cutting off both Extensions to make the Y pipe symmetrical.

Pictures if it works, next Tuesday.

TJM

 

Like Steve, my pass side is in California for rework/recoat. As for my flanges, I've already cut the expander cones off the flanges and am planning to use 2-1/2" mandrel bend to make up either a complete new Y, or I might cheap out and run the new M-bends to a hookup w/ the old Y.
When I spoke to Brian @ Vett tech this week, I asked him point blank
just how important these expander/venturi cones were. He said they're great on a race car as you're trying to get the most out of your setup. They don't do too much under about 5000rpm. Even If I change cams and heads, I think this'll be ok for me. I don't spend much time over 5000, and prolly wouldn't if I could.

If you are one of those guys that absolutely, positively MUST have every ounce of power you can get, then maybe you'll want to use the
cones.

 

If you can hold off a few days, I should have the 3" issue resolved for better or worse.

If 3" welds up against the Extension flange [ and over] the 2-1/2" pipe on the extension piece that forms the venturi, you may get a satisfactory result where we can have our "cake" and eat it too.

4,800rpm is just where stock TPI seems to run out of breath.

 

In a exhaust design article by Vizzard, he points out that race cars use "terminator boxes" to simulate open atmosphere. These are usually placed on the end of the headers (which have a length tuned to the desired peak of the race motor).

For 12" primaries and 12-24" secondaries, he says they have a peak in the 7K-8K rpm range. That's consistent with what Brian claims for these headers.

I suspect the venturi and coupler are an attempt to create a terminator box effect at the end of the header....with one last speed-up and "decompression" to establish a negative pulse back to the heads.

On street cars, the tuning should be lower/longer anyway, so I agree that the use of the venturi should not be "critical". And, I've been somewhat convinced by another forum member that scavenging is minimal on stock/mild motors anyway. That's not to say LT headers can't help pull burnt fumes out of the chambers, just that they aren't really going to help pull in more intake with the small amount of valve opening at overlap.

I would predict the 4800 rpm "ceiling" with the TPI will remain with any header because the exhaust is not the cause. Whoever doesn't like that ceiling should consider an intake swap. OTOH, any header will be an improvement over the L98 stock exhaust system for a couple of reasons...

According to 65Z01, the inside dimensions of the L98 neck down to nearly 1.25". With the air tubes partially blocking the manifolds, exhaust breathing/routing has to be choked -- even for the stock motor. According to Vizzard's charts, you should put a 1 5/8" header on a motor that has the exhaust flow of the L98 (130~150cfm). When you mod the motor and get flow up higher, the switch to 1 3/4" headers makes more sense. (The correct size maximizes velocity at usable rpms and that's what "scavenges" fumes).

Many people talk about the potential gains of intake/exhaust swaps for the L98. After lots of reading/learning, I'm more convinced than ever that exhaust mods are the best change you can make to the L98.

The exhaust manifolds are just too small (for alum head flow). And, the cats/mufflers choke results even further. This is well supported by the impressive torque gains seen with Bandit4142's swap to these headers.

As far as the intake, it might be more correctly-sized than most give credit for. The stock TPI is reported to flow about 185ish. (That's the runner/base combo.) That's also the highest numbers I've ever seen reported for the 113's heads (which are higher than the 128's). You could change the TPI ceiling thru siamesing, or intake swap, but I think the flow is fairly well-matched -- certainly better than the exhaust.

For the changes the stock L98 needs, these headers will accomplish all of the goals with or without the venturi. In other words, any header will accomplish those goals. But, these might do a hair better due to their stepped design.

I just have to wonder if that extra smidge is worth all the extra work!