When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Stuart,
How much would 321 stainless add to the cost of this setup.
Not really sure. We don't have a mandrel bender (yet ) so we buy in bends in UJ and tight radius (1D) in a variety of sizes from 1 5/8" up to 3".
We buy these 300 or so bends at a time. If I order 321 just to fill one order we'll pay way more, end up with a bunch of waste etc. We also have to make parts like this in some reasonable volume in order to build them for a reasonable price. So using alternative metals goes from being a 'normal' production to essentially a 1-off production run.
So the cost goes up a fair bit. Having said that, I don't think 321 is really necessary for this application. We use 304 on the Aston Martin manifolds that are run on the GT4 cars. These cars are running hot enough that they were melting more 'conventional' sport cat bricks and require an ultra high temp brick like the ones we use in McLaren sport cats where they are seeing 24lbs of boost.
The 304 16 gauge is performing extremely well under these conditions, so I really don't see it being required for the Jaguar application.
Okay. Did some durability and heat testing on the V8 on the weekend. Was run pretty hard in several sessions on track and also got stuck in traffic. I think we will still STRONGLY be advising ceramic coating on these, possibly even supplying as standard because I don't want to take chances with heat in the engine bay. Having said that, these were run un-coated with no heat shields and the engine cover removed and zero issues, everything looks good on inspection, zero heat damage so appears that clearance and airflow is all good.
V6 prototypes are almost done - with the extra space it has been much easier to equalize the runner lengths and still allow access for getting bolts in. So far RHS lengths are 22", 21" and 21.75".
And yes Lance I took a picture of the inside of the collector.
Stuart this is great news! I know i'm buying a set for my V6 as soon as your done. I already have your sport cats and tune and have been very please with both. Can't wait to add these headers, a 18mm lower pulley, and a new tune.
Hi Stuart, I'm sorry if I missed it but I didn't see the answers in a previous post. Question, how will your headers be different than the the stock manifold. What is the design. Is it a 4-2-1 design. Is it larger in diameter. What kind of power gain can one expect.
Thanks Stuart
Hi Stuart, I'm sorry if I missed it but I didn't see the answers in a previous post. Question, how will your headers be different than the the stock manifold. What is the design. Is it a 4-2-1 design. Is it larger in diameter. What kind of power gain can one expect.
Thanks Stuart
You can see pictures of the headers in previous posts - they are 4-1 design. Probably halfway between a 'shorty' an 'long tube' design. The V8, due to packaging and access issues doesn't have perfectly equal length primaries. The V6 is pretty damn close to equal. Primaries are 1 7/8".
Pictures worth 1000 words. These are factory V8 manifolds, with our V6 prototypes (the OEM V6 manifold is exactly the same minus the rear branch.
Stuart this is great news! I know i'm buying a set for my V6 as soon as your done. I already have your sport cats and tune and have been very please with both. Can't wait to add these headers, a 18mm lower pulley, and a new tune.
Hey, do you have any videos of what your car sounds like? I'm looking into modifying the exhaust but I don'tknow where to start either the exhaust or the catalyst but I need to decide on one first.
Also have you noticed a huge difference with the power after doing the tune?
To the question of 'will I get more power'... When some of us drag raced in the late 60's we expected headers to increase torque the most and h.p. less. So, I seem to remember engines that put out say 420 h.p. ended up at 435 brake h.p.... these engines had cast iron exhaust manifolds that had not necessarily been well designed.
I recall that the guys that had pure race cars, had longer headers which I think developed peak h.p. and torque at say 3,500 plus... the folks that used the car as a daily driver and street drag car found shorter ones worked best for lower rpm... anyway, these folks dyno tested various assortments of headers and I received my information second hand.
The F would likely benefit from a good header design since any engine is basically a pump that pumps in air and needs an efficient exhaust and my guess is that if you add blower speed, you could benefit even more.
Lawrence
To the question of 'will I get more power'... When some of us drag raced in the late 60's we expected headers to increase torque the most and h.p. less. So, I seem to remember engines that put out say 420 h.p. ended up at 435 brake h.p.... these engines had cast iron exhaust manifolds that had not necessarily been well designed.
I recall that the guys that had pure race cars, had longer headers which I think developed peak h.p. and torque at say 3,500 plus... the folks that used the car as a daily driver and street drag car found shorter ones worked best for lower rpm... anyway, these folks dyno tested various assortments of headers and I received my information second hand.
The F would likely benefit from a good header design since any engine is basically a pump that pumps in air and needs an efficient exhaust and my guess is that if you add blower speed, you could benefit even more.
Lawrence
I suspect that the gains that we will get from headers with our SC engines will be substantially less than what old-school NA engines are able to get. I don't think that my overdriven V6 will benefit from any significant hp gains, but hope to generate some additional torque. We'll see in a few weeks.
Had the opportunity to use a forum member's V6 to check out the fitment on the AWD cars. There's some differences on the engine mounts and clearances to accommodate the electric rack & AWD system, so we re-worked the prototype design. These are the result. Next to Ceramics and then off to Unhingd!
I suspect that the gains that we will get from headers with our SC engines will be substantially less than what old-school NA engines are able to get. I don't think that my overdriven V6 will benefit from any significant hp gains, but hope to generate some additional torque. We'll see in a few weeks.
Agreed on the new vs. old BUT there was a heck of a difference even back then. For example a 427 L88 used very restrictive cast iron manifolds and replacing them with headers made a huge difference (approx 80hp).....opposite end of the spectrum were the Chrysler 426 Max Wedge manifolds which flowed very well. Modern vehicles, especially performance ones simply don't leave that much on the table anymore.
As far as the HP vs. torque goes.....well since hp is just torque x rpm and the headers should help flow at higher rpms (and CFM) more than lower rpms, I'd be surprised if it boosted torque without a corresponding boost in hp. not sure what in an aftermarket header design would hamper high rpm flow ....I await the results.
) so we buy in bends in UJ and tight radius (1D) in a variety of sizes from 1 5/8" up to 3".
either the exhaust or the catalyst but I need to decide on one first.
