XtremeClassics Headers advance look

I'm pleased to announce the first set of stainless steel headers from XtremeClassics is nearing completion. This first set of headers sets the bar for our high end headers. Made from .06" thick 304 stainless with specially tuned merge collectors, double slip fit connectors and ceramic lined mufflers.

The following pics show the still uncompleted set with only six pipes, tack welds and no muffler support bracket.

Once you feast your eyes on these I'm sure you'll be able decide what you really want for Christmas.









These and other header pictures can be seen on the XtremeClassics website headers pics page.

Wow Mark,

What incredible detailing! This engine bay is by far the nicest I have seen so far. I hope you are going to post many many more pictured on your website!

Congrats on the awesome work!

Looks great! What size primary and collectors are you using? It looks like you have the wide bolt pattern at the head exhaust (3" on centers?).

Mark,
Very nice work on the headers!

One thing I notice is your throttle cable coming in from the left side of the engine over the exhaust system.
I did my car the same way except using TWM throttle bodies. I can pass on a few things I've encountered.
My exhaust system is also 304 stainless, no coating. The throttle cable was getting hot enough to actually melt the outer jacket of the cable. I've wrapped it with ceramic insulation and a Nomex braided cover. Even so, after the car gets warm, especially if you stop the car and leave it idle for any length of time, even at at stop light, the cable wants to "stick" just off idle. When it's cold, no problems.

This winter, I intend to get the stainless ceramic coated to reduce under body temps. I also plan to change the linkage to the injection so the cable can pass down the center of the engine between the throttle bodies/over the intake.

Dave

Mark,

Absolutely beautiful! As pretty as those headers are, it would be a shame to cover them with ceramic or a wrap. Is there any other way to route your throttle cable? From the front or back, down the inside of the valve cover, to a bellcrank?
What was the price on those beauties????? I gotta have a set someday! A work of art,IMHO!
Oh, Santa! Please can I have a set for Christmas?

Bill

What will be the effect, on performance,not having them equal length primaries?
Thanks
Nathan /ubbthreads/images/graemlins/cool.gif <font color="blue"> </font>

What are we talking about for price?

These pipes look beautifully made and presented, first class workmanship, but they could not be used in the UK, either road or track, they would just be TOO LOUD. We have very stringent noise levels here, and even our "noisy" days at Goodwood mean we have to pass a noise test of less than 105db measured 3 feet from the tail pipes at 3/4 maximum revs. Now a healthy engine going over 4000 revs starts to really bellow, and even with our large silencers we struggle to convince the marshals we are within the limits to allow us out onto the track. Once on track we are constantly monitored by trackside microphones feeding to a computer, and we are then subject to 98db drive-by noise levels or we are pulled off and sent home. So, lovely as that system is, I am afraid it is no good here. Frank

No good in the UK if the only place you compete is Goodwood. There are other places./ubbthreads/images/graemlins/cool.gif

AS PREVIOUSLY POSTED BY MARK


I have designed and completed cutting all the steel to fabricate a jig for manufacturing headers for ERA GTs. I'm hoping to have a set of premium stainless headers to show the group within 1 month.

We will be offering GT40 reproduction headers in stainless and mild steel. Guess I need a real web site now.

The stainless set will use all 304 stainless with Burns designed double slip fit merge collectors. They are going to be sweet. I'm hoping these will come in around $3500.

The least expensive mild steel set will use collectors that are nice but not the best. These should weigh in at $2400.

Want something in between? Fine. We're flexible. We can get inconel if you have $10K burning a hole in your pocket.

We'll have the jig for ERAs but can work with any car if we can get it in the shop for a couple weeks.

My thanks to Bill Tuttle for use of his shop and his help. Buy all your commercial doors from this man.



They are beautiful Mark...job well done.....
England is not the only place in the world that people have GT40 replicas and very few people (percentage wise) seriously race their cars anyway.....I dont think there will be a shortage of buyers....how fast do you think you you will be able to deliver once they are in production?
Also when in production will they be one piece pipes or will they continue to be welded bends...

I've always been a big fan of equal length headers on any cars I've owned, and thought this was the key to a great crossover system, whether on the street or track. Although I'd be happy with any GT40 crossover set-up, if I was spending big bucks I'd expect every ounce of performance. Although this is an awesome looking system, I'd look for a set of tubes within 2-3 inches in length. Am I way off? Have I missed something? I'm interested in anyone's thoughts on this.

Rob
"If we were all born equal, why is it that I can't afford a real one?"

Thanks for the comments folks. I'll try to respond to each question or comment in sequence.

Gary, these are 1.75" primaries. The collectors are tuned to the engine bore, stroke, cam timing, rpm range and more. They came out to be 2.25" transitioning to 2.5". Bolt pattern on my Victor Jr. heads is 2.00" but I've seen them at 2.5" and 2.75. I can get 304 ss flanges for almost any engine.

Dave &amp; Bill, I'm hip to the throttle cable. I've been waiting for these headers to be able to pick where the cable runs. I have the choice of where it is now and between the front two cylinders. Guess its time to pull some throttle shafts and position the cable between the front two. Also I'm planning some snap-in heat shields so running the throttle cable up front will allow me to run it outside the shield.

Nathan, Having unequal length primaries will adversely effect performance. Not my fault. I'm just trying to duplicate the most popular headers design seen in small block GT40s. Original afficionados will notice the primary for cylinder number 7 is not quite right yet.

Ron &amp; Bill, Big groan on the price. Hardware as seen is $2500. Labor has run over 40 hours on this first set. This is not unforeseen. After a few sets are completed I imagine we can get the hours down to 32. So that's another $2200 minimum. Can we have a collective groan at this point?

This is my "top end" offering so there are ways to reduce the price. Generic super-nice collectors instead of the tuned ones will save a couple hundred. You may not want the $400+ each ceramic cartridge ultra lite mufflers or the double slip fit connectors. That would be a $600+ price reduction. I'll have to make up a matrix of options. These are 16 gauge (.065") but we can get down to 20 gauge (.035")

Frank, I have no idea of the muffling characteristics of these mufflers. I know the 180 degree design is quieter by default and hese mufflers are used in USAC and SCCA in the states. We'll have to wait for the db level tests. We can fit other mufflers if these don't cover your noise level requirements.

New Product Alert - If you think these headers are sweet wait until you see my carbon fiber/graphite aerodynamic devices. First splitter should be ready before Jan 1.

Email me at [email protected] for more info.

Mark

Rob,

You're on. For which car and head/engine combination? If you're not concerned with them being "replica" then there's a lot more we can do given today's technology. How about a set of equal length stepped headers? You asked for Xtreme? Email me at [email protected] if you want to persue this.

Fran,

We hope to get the process of building them down to 32 hours. That does not consider any lead time for parts (2 weeks min.) or other scheduled work.

I'm not sure about developing an NC routine for bending pipes for the GT. There are so many variations of engine and manufacturer it would probably not be economically feasible.

As an added option we can make those welds disappear and have the whole system professionally polished. We can make them look one piece.

Truly superb! - great looking exhausts.

It's worse than you think Frank - in theory I think the noise test is officially to be taken 0.5M at 45 degrees to the exit pipe, so half the distance. LOUD!

Also, whilst we love Goodwood, I've driven Donnington and Snetterton on noisy days where there were no noise tests so if your car is more track than road, they might be ok.

Thinking of Snetterton, that was interesting as they stuck Dave Parker (R42) and I out with the 'supercars'. As it was belting down with rain and my first drive at Snet, I'll never forget the sound or sight of a Lemans Silk Cut Jaguar passing to my left, somewhat faster than I and to then watch it take the next corner without lifting as I continued to struggle to scrub speed from about 100. Downforce!!!!!!!

(I did manage to pass FEL1C a couple of times during the day though once my confidence was up.... &amp; the rain had eased) /ubbthreads/images/graemlins/grin.gif

What we need is some sort of agreed measureing specification to get a view on different systems noise levels. I am told that for this coming year both the noise tests for SVA approval and for our track days are going to become even more carefully measured and controlled, with very little latitude given. So, as we do not want to be in the same situation as we are with dyno results and horsepower variations, not to say ET times for 1/4 miles, why don't we agree to measure noise levels at say 1M (3 FEET)from the rear of the car at 4000 rpm, and see what the results of different systems are, remembering that both lower horsepower engines and inefficient silencer designs will always get a lower db figure but also lower performance. Frank

Mark

GREAT workmanship on the car and the exhaust.
Who could ever be disappointed to find out this is a replica???

MikeD

Frank and all,

We would need to be out of the way of the exhaust flow as this will corrupt the measurement. We would need to use a wind screen on the mic (sound level meter) which looks like a foam ball. Then there is the question of frequency weighting. Most measurements of this nature are dBA (A weighted). Do you know what the SVA requires?

Gary, I agree, and as Paul says, we are normally measured at 0.5 m and at 45 degrees to the exhaust outlets. All I was suggesting was to see if we could get a commonality to get a guage on the noise levels of the various exhaust systems. Having played around in a small way with silencer design for these cars, and knowing just how bad the standard systems can be in both noise reduction and power efficiency, I am intrigued to find the best solution. Frank

Hi again -

Frank - I chose 0.5M distance and 45 degrees as that is what is specifed in the official MSA Blue Book of regs - (E.12.17) although they do also give readings for 2.0M &amp; 8.0M distance.

O.5M is generally chosen as the meter can then be attached to a stick protruding 50cm then bent through 45degrees for another 20cm or so. The idea is the person measuring sound just has to line the last 20cm with the output pipe, the bend being at the pipe end and the meter is then automatically positioned 0.5M 45Degs from pipe exit.

I was involved with the official noise testing at the British Rallycross Grand Prix some years ago and it was interesting to see what people did to get their noise levels down on race day. Even more interesting seing those that cheat! /ubbthreads/images/graemlins/grin.gif

As also stated above - wind shield (muff) and measurement mode are also important + no building or other vehicles should be within a specified distance so reflections are not an issue either. - complicated? it can be.

You do make things complicated Paul, all I suggested was to find a level playing field to compare the different ideas that exhaust system designers/builders have, but I suppose if we cannot even get close on a HP/ET/1/4 MILE US/UK common ground what chance have we ?