aww thats sucks..i was really hoping a STR owner would have bought them so the rest of us would mnow to buy them or not. oh well money talks.

 

I was interested in buying Super_jags headers but felt that the time and effort for their install is to be performed at a later interval. I'm still working on the exhaust and suspension. I or one of us will be doing headers sometimes in the near future.

 

i cant wait to see if they fit. i have a crack in my exhaust manifold that i hear on cold starts & it drives me crazy. soon as i hear the headers fit i will be ordering a set of my own.

 

So, did someone buy them? Are they installed?

 

I spoke with Chris of Mina Galleries. He owns Jags and knows the STR and XJ's upside down. He describes the STR's exhaust manifolds as small, low restriction, and down sloping. He feels headers are not a cost effective power builder on the STR. He does strongly suggest hi-flow cats and thereafter as necessary for build-ups. Magnaflow hi-flow cats go on Tuesday.

 

Yeah I bought them, dont have a Jag STR though. They are going on my lincoln ls.I Have not received them yet, being shipped tomorrow.

 

Damn. Don't agree with Mina though. A good set of free flow headers, coated and attached to a free flow exhaust will most definitely free up some power.

 

could someone email me this pdf, im a junior member so unfortunatly cant view it im attempting a ls to jag engine transplant and think that the diagram would be really helpfull

 

so i ended up selling these headers two days after getting them because a turbo deal was offered to me and these headers couldn't be used with it. The guy I sold them to traded his ls before installing so now he's selling them too. Anybody interested int hem? He's also selling aftermarket rims he took off his ls, so they'll fit your jag's too.

The lincoln thread
http://www.lincolnvscadillac.com/showthread.php?t=70986

His email
candyapplered321@gmail.com

 

tempting, but seeing as now one tried them on a STR.....I dont want to be the guy to get them n not fit

 

Problem here is cost. We know the flanges will work on the block. Anyone who can mig weld can modify them to fit, if there are clearance issues but that doesn't come cheap. Then there is the issue of how these will affect flow - just how restrictive ARE the stock manifolds, and if so, where the torque curve will go relative to engine speed.

I'd give it a shot if I had an STR, but I'm two cylinders and a supercharger short for now

George

 

I have a welder, I have the tools, but I HATE doing headers! My back is getting too old for all that.....If I knew they would work and be a gain I owuld of bought them the first go around....but they are still very tempting as I know a good coater for them

 

That's the big question. Will they add any power? As far as fit the EGR tube is definitely needing modification. The Jag has the connection up high and the headers have it down closer to the collector. Looks like the same flange connection but in a different place. The header does come with an extension for the EGR but I don't know why?

If they are stainless steel do you still need to coat them?
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If that's what the stock exhaust manifold looks like, I guarantee those headers would be a horsepower gain. The long separate tubes prevents exhaust gas pressure waves from being pulled back into ajacent cylinders when the exhaust valve opens.
If they fit an STR, I'd cut off that small collector and weld a reverse taper megaphone in place to help scavaging too.

 

First of all, the extension is made to connect the EGR, where is suppose to be, closer to the top much like the factory manifold showed in your picture. Second the coating is mainly to keep the excessive "heat" out. Our car like all the cars today have knock sensors, so if the engine was to get too hot the computer will sense it, and retard the timing... This is to save the engine from detonating, which is absolutely bad. The good part is that this will save your engine, but the down side is this will cut the power too. So having in a long tube set headers will increase your power but as heat build up inside the engine bay your ECU will cut back the power. So what’s gain is lost too.

From my personal experience in my Northstar Fiero, by replacing the stock headers with "long tube" (31inches), made me 30hp average across the power band. Definitely good. But the N* is a NA engine, my best guess is that a Boosted engine like the one in our STR’s will gain this much, but is more likely it will be more than a NA engine with similar size. I will not be surprise if a 40Hp showed in a Dyno graph! =)


As a side note I've called https://www.byunspeed.com/login.php like 3 times today, and I just keep getting their answer machine. So I'm about to give up. I really wanted to get them but I’m running out of time, and my biggest concern is the sound it will make, it will probably sound like a Ford Mustang Cobra, but it looks like a little Rolls??? Is a tough call, but definitely the place to look for power in our cars, since our SC are so inefficient. A free flowing CAT and muffler can only do so much, the real bottle neck will always be the exhaust manifold.

 

Agreed 100 %. Stock cast iron manfolds are the biggest killer of performance on these engines. I've never seen what they looked like until that pic was posted. (Too busy to even look at mine) Boosted engines need all the help they can get getting the exhaust out. NA engines benefit from a tuned header to help pull the new air/fuel charge in- get too big or the wrong length and it doesn't help pull it in. Dirt track Late Model engines (374 cu in making 800 hp) that I've done gained 25 hp from tri-y merge collector headers.
I'm getting ready to do some flow bench R&D on Ferrari heads for a twin turbo godzilla engine combination that nobody has ever done before. We'll be putting 90% of our efforts towards exhaust flow.

 

Those cast iron exhaust manifolds pictured are from a Lincoln LS, not an STR.

 

I would rather have shorties than long tubes....like stated I dont want to be loud like a Mustang, again

 

They are almost identical

 

Then I like the stock manifolds...and they look cool too.