Header primary size

[8AV8]

I got a set of stage 2 N/A headers. They are long tubes with 2 inch primaries. I got them cheap, to convert/beat into submission to fit 8445's. They're pretty cool looking and I just got a tig... There's another one of the extensions

I have a Champion iron headed ,stk stroke TSM combo. Nothing crazy. 70hpq.

Will the 2" primaries kill me?

Better question...anybody have a link to header efficiency relative to primary size info on turbo applications?...or better yet, experience trying out it on a TR...:smile:

I'm still gonna hack these b!tchez and fit them to 8455s regardless. So if nobody else has tried it, we'll know soon. (or kinda soon)

 

[8AV8]

pic

 

[charlief1]

You're going to have problems fitting them to a set of 8445 heads Chris. The largest tube that's been put on a set of those heads is 1 & 5/8" for a reason.

 

[8AV8]

You're going to have problems fitting them to a set of 8445 heads Chris. The largest tube that's been put on a set of those heads is 1 & 5/8" for a reason.

I'm not worried about fitment so much. I can make them physically fit it the car.

I'm curious about back pressure and spool time. How they could effect horsepower. + or -

 

[8AV8]

another

 

[dr_frankenstein]

sounds like a good waste of stage 2 headers.

id sell them for a good few bucks and use that toward a really nice set of jays headers or TAs

A.j.

 

[V6RACER]

bring those things up here and we'll test fit them on the silver car

 

[disco stu]

I doubt it, but lets see it. The flange is nowhere close and the bolt spacing on the 8445 is too close for a primary of that size. Not to mention that the exhaust runner is way too small to ever use a primary that large. And the fact that it is gonna take ALOT of work and head scratching to convert them for a turbo app.

Sell em, buy a set of headers that fits.

 

[yullose]

lol... I don't think you could find a worse pair of headers to fit an 8445 head.

First thing that comes to mind is, what were you thinking ???

Are those off an old Busch/Arca car or something ?

 

[turbofabricator]

Give it a try, Spend 60 hours hacking and cutting, buy new flanges to fit 8445 heads, grind thermal coating off all tube seams (inside and out) prior to welding, buy MORE tubing bends to make it mate with the turbo, buy v-band clamp assy's to join the pieces, send them out for new thermal coating, start engine, let it warm up, stand on brake hard, put in gear, bring boost up against the converter.........keep standing on the throttle..........wait.......wait.......wait......still no boost......wait for five more minutes.....give up........pull the $2,000+ headers off and call the guy you sold your stock ones to and PLEAD with him to sell them back to you for $50 more than he paid. Hang the cool looking headers on the wall and grumble profusely every time you look at them. Then put them on E-bay and sell them for $250 to someone else that thinks that headers are a big improvement needed on a Turbo Regal.

So,..........in other words, DON'T DO IT!!! It would be a COMPLETE waste of time. If they can get a car to run 204 MPH in the 1/4 with mild ported cast iron Chevy truck manifolds, there just isn't any measureable power gain in true tubular headers for cars running 10.0 or slower. You will have about an hour in EACH weld joint after grinding off all the thermal coating. If you want to build a set of headers, just buy a box of U-J-bends in 304 and a pair of header flanges, and have at it. Be sure to buy the tubing in 1.625 or 1.5" for the primaries. Keep them as short as possible and don't fret over equal length, either.

 

[8AV8]

OK, let me ask it in another way.

The car is faster than 10.0.

I got a 400 with a griner.

I paid $119 on ebay and I was the only bidder.

I bought another set, by another header maker, for $99. Different design...but plenty of bends for not a lot of $$.

I built my 3.5" dp (with a v-band clamp between 4 and 6 area) and all the way out the back for less than $300, mild steel, including the muffler. 3.5" stock exit location.(box of 10 aluminized 2nds off ebay for 50 bucks to my door.:smile Got another v-band assenbly before the muffler, also.

I cut a 44mm tial into the stockers.

I even cut the turbo flange from a piece of plate.

I used a milling vise and a drill press to make my battery tray.



This will be easier. I didn't do:

engine internal
tranny internals
cage
rear end set-up.

I did do:

everything else but the tune.


No offense, because I respect the heck out of tfabricator's skills...but I wasn't asking if anybody here thinks they will fit or not. If you don't see yourself being able to handle doing it, well....sorry. I CAN.:smile:




SOOOOOO....

Does anybody have a clue how this conversion would affect PERFORMANCE?

 

[8AV8]

I doubt it, but lets see it. The flange is nowhere close and the bolt spacing on the 8445 is too close for a primary of that size. Not to mention that the exhaust runner is way too small to ever use a primary that large. And the fact that it is gonna take ALOT of work and head scratching to convert them for a turbo app.

Sell em, buy a set of headers that fits.

What happens to performance stu? Really. I'm gonna do this because I am an idiot that loves pain> IF...there isn't a DEFINITE hp kill going this large based on experience or knowledge from other endeavors.

Thanks dude.

 

[yullose]

If the large, long tube Hooker headers kill performance, those would probably be 10x worse.

Velocity is what spools a turbo, not tube size.

DonWG uses large tube primaries that merge into small collectors... but they are near equal length. His motor is also a destroked, high RPM combo.

Honestly, I think you'd be better off buying a pair of flanges to fit the 8445 heads and just build a hotside from scratch... or just buy a set already proven to work, like stockers, ATR's or TA's.

 

[Alky V6]

What do you imagine this thing looking like when you're done? Are you going for equal length? If not equal, then long tube, short tube? What rpm band are you running at? What are your cam specs?

From a performance point of view, which is what I think you're looking for, your answers to the above questions, I'm sure, are not even going to come close to justifying a 2" primary. Even with the radical specs of my engine, I did a lot of research, and calculated that I wouldn't need more than 1 3/4".
Now, if I were using stage II heads with a wild turbo cam and reving to 9,000 rpm, then heck yeah I'd be throwing some 2" primaries at it.

Long story short, 2" may look cool, but it won't help performance in your situation.

 

[8AV8]

What do you imagine this thing looking like when you're done? Are you going for equal length? If not equal, then long tube, short tube? What rpm band are you running at? What are your cam specs?

From a performance point of view, which is what I think you're looking for, your answers to the above questions, I'm sure, are not even going to come close to justifying a 2" primary. Even with the radical specs of my engine, I did a lot of research, and calculated that I wouldn't need more than 1 3/4".
Now, if I were using stage II heads with a wild turbo cam and reving to 9,000 rpm, then heck yeah I'd be throwing some 2" primaries at it.

Long story short, 2" may look cool, but it won't help performance in your situation.

I'm on a budget. 1200 bucks for headers eats up money that can go other places.

I don't care...at all...what they look like. Aesthtics are not important. As close to equal length as possible is a goal.

I want to step up from where I am with the stockers...and this costs me less than 500...on the high side. And I LIKE welding/chopping/..grinding,not so much.

I don't know how to calculate efficiency for this. I just don't want to HURT where I am now. If I don't pick up...cool. Hell...if I slow down...cool. I'll figure it out and learn a ton in the process as always.

FWIW...the hours I have in the stuff I've made is obscene. But it teaches me. Anybody can write a check for parts. I'm proud of how the little crap I've fabbed is working. Just keeping the train moving forward trying to learn.

If nobody knows...I'll be the guniea pig. What's the worst that can happen?

 

[yullose]

If nobody knows...I'll be the guniea pig. What's the worst that can happen?

I'm pretty sure everyone who's responded in this thread knows exactly what the outcome will be and has tried to tell you.

You are just too stubborn to listen.

 

[Alky V6]

Chris, you go for it. I should be the last person to suggest that you're wasting your time. Your last post reminds me of myself. The only difference may be that I performed countless hours of research and had a very well defined end goal before I made the decision to fab something up.

Good luck and let us know how it turns out.

 

[V6RACER]

Chris on the performance I don't know what will happen.. I would guess that in a three bolt housing limited situation there might be some gain from having a little more volume on the exhaust side. 2" or 1-7/8", don't know, just have to try and see what happens.. I'm sure others said stuff wouldn't work on faster cars before and have been proven wrong.. Trying new things isn't a bad thing..

 

[turbobitt]

I got a set of stage 2 N/A headers. They are long tubes with 2 inch primaries. I got them cheap, to convert/beat into submission to fit 8445's. They're pretty cool looking and I just got a tig... There's another one of the extensions

I have a Champion iron headed ,stk stroke TSM combo. Nothing crazy. 70hpq.

Will the 2" primaries kill me?

Better question...anybody have a link to header efficiency relative to primary size info on turbo applications?...or better yet, experience trying out it on a TR...:smile:

I'm still gonna hack these b!tchez and fit them to 8455s regardless. So if nobody else has tried it, we'll know soon. (or kinda soon)

Let me tell you about some of my dyno experience with the heavy duty diesel stuff. We were do some manifold testing with different volumes. Most people think of the exhaust back pressure as a steady value but when you look at the actual signal pulse, the average value or "gage" is just an average. The actual pulses in the manifold can be much higher then the average value. These pulses are important for spool-up by exciting the turbine but also can contribute to valve float. When we switched to a bigger volume manifold, it acted as a big accumulator and dampened the high pulses and brought the average pressure down. The purpose of or test was to reduce valve float but the same logic applies here. The large tube headers may not kill steady state performance but spool time will suffer significantly.
Allan G.

 

[8AV8]

Chris, you go for it. I should be the last person to suggest that you're wasting your time. Your last post reminds me of myself. The only difference may be that I performed countless hours of research and had a very well defined end goal before I made the decision to fab something up.

Good luck and let us know how it turns out.

Thanks Don. This is the beginning of my countless hours. I'm just looking for the wisdom of those who have gone before me.

...As is pertains to 2" primaries on a TSM 109 anyway....:biggrin::biggrin: