Hi!

I think a complete GTA exhaust would be a nice goodie for your 1600er engine.

Greetz Clemens

 

People far more knowledgable than me will probably chime in later, and have done in the past (do a search on here). Basically, it depends what you're going to be using the car for. If it's road use, remember the old phrase that "horsepower sells cars, but torque wins races". The standard exhaust manifold is much better suited to scavenging exhaust gases at low-to-mid revs and will help to produce better torque figures, whereas the GTA-style headers will only work best on a 'hot' engine that spends most of its life at higher revs. The headers will also throw out a lot of heat, although extra heat shields and/or ceramic coating can mitigate this effect. Do a search under "Magnaflow" for a discussion a few months ago about one particular exhaust sytem in stainless steel that seems to have found some favour. And as ever, let the rest of us know what you found out!

Alex.

 

AlfaBB will be offering the new MAGNAFLOW (http://www.magnaflow.com) exhaust systems in the very near future. The systems are being designed to replace the stock GT exhaust from the 1600 to 2000's. They will be made from stainless steel mufflers and stainless steel tubing 2.25” in diameter. They should also be retailing slightly over what it would cost to purchase a stock system. More news, photos and sound clips to come soon.

 

Here are a few pictures from the prototype.

 

magnaflow

Regarding the new stainless steel exhaust for GTVs...
It looks wonderful and I understand what you've shown is a prototype. In its final form, please make sure the tailpipe extends beyond the bumper and bumper overider. It would be a shame to miss that small but gaseous detail.

GMack
GTV hibernating
Minneapolis

 

The hanging brackets don't look all that sturdy, either ....

 

The pipe exit length is aproximatly the same as a stock unit. Are you suggesting that it be longer?

 

Hi,

I'd also recommend the GTA system. You gain torque and power. Even with a 1300ccm engine, even though the diameter is on the big side here. Don't matter the often heard "equal lenght" argument, it is far more important to have large and smooth rounding of the pipes and the correct diameter. It is not easy and far away from cheap to design a better system for a 1600ccm engine.

Best regards,
Sven

 

The pipe exit length is aproximatly the same as a stock unit. Are you suggesting that it be longer?

Simon,

People have commented in the past that exhaust gases inside the cabin have been exacerbated by poor trunk sealing and a non-standard tail pipe. From what I understand of the problem, the pipe needs to be a certain length, angled down slightly and with the slanted end in order to scavenge the exhaust gases away from the area of slightly negative air pressure that is known to build up at the rear of the car while at speed.

Alex.

 

Hmm, I have a non standard tailpipe and don't have any problems...guess my trunk seals are good ("art! art! art!")...

I second the Magnaflow...though mine are still in the boxes on the shelf in the garage...next to the car that is waiting to have the engine pulled and tranny gone over...argh...but the POR-15 looks sharp!

Ted

 

Thanks for your replies. I'll wait a while for the Magnaflow system to become available -- it looks like you'll have a nice product. In the meantime, at least my old car doesn't have to pass an emissions test!

 

I have run a complete original GTA system (with the exception of a tail pipe without rear resonator) on a stock 1600 (only cam timing slightly changed and carbs rejetted) single plug road car (Giulia Super).

Headers were aluminized (metal sprayed) at the time - this was before ceramic coating. Clearance under the floorboards was an issue (needed to be dimpled in a major way to fit headers and the heat shield had to go). So was heat under the floorboards (without the heatshield the feet got very hot on extended full throttle travel); albeit I only killed one alternator in over 100,000 miles and this was not likely due to heat.

Now the clearance issue may be non-existant on a GT but I don't know.

Driving, the first thing that was noticeable, apart from more noise from the tubular headers and a crisp and raunchy exhaust note above 6000 rpm was much more torque low down and better fuel consumption (jetting was slightly rich previously). Also hi rpm performance signifcantly improved.

Apparently, there is an issue with reproduction GTA headers not making the same power as the original. There are supposed to be differences in pipe diameter, with the replicas being larger than the original. Also the replicas are mandrelbent rather than sandbent and therefore not shaped conically.

I personally have some potential reservations about the Magnaflow system, as it doesn't have the front resonator after the header. I have run an original standard Alfa exhaust (without the tail pipe resonator) and without the front resonator and low-down torque all but disappeared. I always attributed this to the front resonator acting as an expansion chamber. Maybe that effect does not occur with the rear resonator fitted.

 

I have stock manifolds bolted to a ansa downpipe which has the 1st resonator. From there I deleted the big central muffler and go straight to the rear resonator/tailpipe which is stock. The intermediate pipe is stainless and welded to the downpipe. I cut and used the big muffler outlet to match up to the rear pipe. The sound is rich and above 3 grand gets raspy and loudish. Just enough ( for me!) to match the intake. The intake being Alfa 3 inch kicked air horns. I wonder if headers really offer that much difference? I doubt it for the cost, Joe

 

I personally have some potential reservations about the Magnaflow system, as it doesn't have the front resonator after the header. I have run an original standard Alfa exhaust (without the tail pipe resonator) and without the front resonator and low-down torque all but disappeared. I always attributed this to the front resonator acting as an expansion chamber. Maybe that effect does not occur with the rear resonator fitted.

Initial dyno test on a stock 1600 showed an increse in both Torque and HP without the front resonator, and that was with the unrefined prototype.

 

Headers were aluminized (metal sprayed) at the time - this was before ceramic coating. Clearance under the floorboards was an issue (needed to be dimpled in a major way to fit headers and the heat shield had to go). So was heat under the floorboards (without the heatshield the feet got very hot on extended full throttle travel); albeit I only killed one alternator in over 100,000 miles and this was not likely due to heat.

Now the clearance issue may be non-existant on a GT but I don't know.

Driving, the first thing that was noticeable, apart from more noise from the tubular headers and a crisp and raunchy exhaust note above 6000 rpm was much more torque low down and better fuel consumption (jetting was slightly rich previously). Also hi rpm performance signifcantly improved.

Apparently, there is an issue with reproduction GTA headers not making the same power as the original. There are supposed to be differences in pipe diameter, with the replicas being larger than the original. Also the replicas are mandrelbent rather than sandbent and therefore not shaped conically.

I have the repro GTA system (IMASAF brand) on a '72 GTV 2000 and have been very pleased with it. I required a little work to fit due to the difference in height between a 1600 and a 2000, but it wasn't bad.

It has a front resonator and center muffler in the single long center piece. I use the GTA tailpipe without a muffler, they are also available with a muffler and the diameter is 60mm.

They do make good power and sound great. They get a little hot - I believe some heat shielding in the engine compartment and/or ceramic coating the headers will solve this, but it's more of an annoyance than a major issue for me at this point. I believe the repros use thicker tubing than the originals so engine heat is not as bad.

The other benefit of this system that I constantly point out to people is that it's all connected by flanges. This means you'll never have to pull apart a nasty slip fit joint when servicing the car!

So overall, I highly recommend this system.

Joe

 

The other benefit of this system that I constantly point out to people is that it's all connected by flanges. This means you'll never have to pull apart a nasty slip fit joint when servicing the car!
Joe

Joe,
You are correct as long as the slip fit joint is held together by a u-bolt type clamp; which will crimp the outer and inner pipe sections. However, the new cool design in exhaust systems is to use a wide stainless steel band clamp (Torca is a popular one at the moment) which will not crimp the pipes in the slip fit joint section. The outer pipe must be notched for this to work properly. Sorry for picking the fly sh## out of the pepper.

 

The secondaries look too long as on the stock pipes. Can they make them no more than 15" long?

 

Does Magnaflow stock the wide band type clamps? I'm in So. Ca. and need some for my system.

 

The secondaries look too long as on the stock pipes. Can they make them no more than 15" long?

Longer is better for low end torque. Short for high rpm. Alfaholics in England has a very good SS system derived from their race experience.

Why is the reader told to search for other threads for the Alfaholics reference and subjected to an advertising push for the Magnaflow product?

"AlfaBB will be offering the new MAGNAFLOW (http://www.magnaflow.com) exhaust systems in the very near future"

And WHAT is the BB doing selling anying???? Do you mean some individual connected to the BB, who will profit from a captive market?

Something smells bad.

R

 

Having seen the Magnaflow shop and their products, I can see why members are RECOMENDING them to others. They make a great product!

 

uh.......Robert, I think you might have missed this thread: http://www.alfabb.com/bb/forums/showthread.php?t=18966&highlight=alfabb+store

 

uh.......Robert, I think you might have missed this thread: http://www.alfabb.com/bb/forums/showthread.php?t=18966&highlight=alfabb+store

I going to go out opn ledger here but I think Robert knows quite well about that thread and the BB Store .

 

Quite right. I read all of that thread. In fact, I just re-read it all to be sure my biases didn't color my memory. Several concerns were expressed about the potential for bias.

And this thread is one example. If the AlfaBB Store were just into things that aren' otherwise available, there would be no conflict. But in direct competition with other very well regarded suppliers?

I do not mind that the BB owner sells stuff. Alfa stuff is hard enough to find, and this BB is a solid gold resource. What I worry about is that BB rules will drive away resources.

For example,is was posted by a potential parts supplier in the thread "Liquidating Alfa Dealership":

"Alfa-of-Corse
NOS parts
I have most of the parts that people have expressed an interest in, but not all, however new BB rules mean, NO SALES THRU THE BOARD.
__________________
SW Pa.
76 spider
73 GTV"

So the Alfa store is now EXCLUDING exactly the people I want to find.

This is wrong, and will kill this BB if the experts - who post their knowledge for free here and occassionally sell a part or service too - go away.

THIS IS WRONG!!!!!!!!!!!!



!!!!!!!!!

Robert

ps - sorry for typos. my keyboard seems to not like r's and t's so I have to edit to fix.

 

BTW - I like he Magnaflow exhaust too - similar to the Alfaholics and lots cheaper wihout Atlantic freight costs. I'm just worried about the bias the can creep in so easily.

I have an ongoing need for obscure parts, and always wish I knew something that other members have at the tip of their tongue. The BB has been magic on both counts and I fear any change that threatens that.

I saw the line I quoted on the "Liquidating" thread and did not understand 'till this one. The problem seems immediate!


R

 

Robert, you make a very good point about not driving away suppliers. In fact my recent purchase from Alfaholics was influenced by reading their excellent info here on the BB. It convinced me that these were real Alfa People.