has anyone put headers on there 07 turbocharged mcs? i was looking to increase some more speed. already did a few mods like the JCW tune kits and need more... any suggestions? if headers are a good mod wheres a good place/site to get them and are they tough to install?

 

you can lose power with headers on a turbo car.Tubular headers have more surface area exposed which causes the exhaust gas to cool and become dense.With a turbo the more heat you keep in the exhaust charge the quicker reponse time and will make more power overall.

The place to look for flow is the turbo because the exhaustside is the bottleneck from the exhaust port to the tailpipe.

 

thank you james. so do you have any suggestions to increase speed more then what i've already done to get me a few more horses?

 

rmw tune,a factory jcw turbo and map sensor,forge or helix intercooler, catless downpipe,water meth injection, 2.5 + inch catback.

 

in your opinion what will that increase?

 

You really need to back this one up with research and many more pros and cons. Don't shoot from the hip. This community doesnt need any more false or partial information.

Correctly made tubular is far superior to a cast oem manifold. However they are not as durable or reliable.



Tubular
No Pulse overlap(eliminate overlap=decreased spool times!)
Reduces heat to turbo(longer turbo life) note: heat can be held in with wrap
Less reliable (crack in welds and lighter thinner material)

Basically a tubular made correctly is tuned for exhaust flow. Allowing each pulse from the cylinders to fall into a rhythmic pattern of vacuum and pressure to help the exhaust flow move efficiently through the system. Pulse then vacuum then pulse. The system is usually designed to not allow the exhaust pulses from one cylinder to interfere with another.
A fake or un-tuned tubular manifold can have horrible performance.
The runners are also larger than a cast oem manifold allowing for a larger volume of air to be moved along(complimenting performance parts).

Cast
holds in heat(not needed for spool with our small lil turbo)
Durable
Small runners
Mash the pulse exhaust together(i think mini has a divider to help)


Here is a good read from Garrett Turbo

http://www.turbobygarrett.com/turbob...o_tech102.html

 

THIS IS FACT NOT FICTION

The exhaust side of the turbo will always be more restrictive(flow less cfm) than a exhaust manifold or a header. Think of it as a hose(exhaustport to tailpipe) that is pinched(hotside comp wheel) in the middle.

I have seen tubo camaros and corvettes gain 80+hp on a dyno by removing tubular headers reinstalling cast iron exhaust manifolds .

Anything done to free up flow after the hotside wheel will help and make HP.(downpipe,exhaust)

 

I dont disagree with you about the rest of the exhaust. Of course it does help and its severely pinched off. That is why great gains are seen with the dp/cat removal and catback combo or turboback system.

Overall the exhaust should work in sync for best flow possible. Header/manifold all the way to the tailpipe.

But I do disagree with your tubular vs cast oem manifold post. Tubular is far superior correctly made and tuned.

 

200 TO 210 WHP DEPENDING ON CATLESS OR NOT.

 

Emphasis on the above.

 

You could have 2 inch primary headpipes going to a 3 inch collector but if the bottleneck is further downstream the header wont help and most often will cost power or increase lag.

 

All you guys are forgeting that the Mini has a twin scroll turbo manifold. This is why it spools up at such a low RPM. This means that the exhaust manifold has a split path into the turbo that uses the pulses of each cylinder to speed up the turbo much quicker than a single opening to the turbo.

We change out the factory manifolds for tublular ones on 911 turbos all the time but with that car you have three cylinders firing into each turbo. A tubular header works wonders on that car for more mid and upper RPM power without affecting spool time.

I would bet good money that changing out to a header on our engines you'd take a lot more time for spool up and lose a lot of that low end punch that I love so much and not get big gains at the upper RPM due to such a small restricted turbo.

 

on a boxer ,v configured and multiple rotary with big turbos that are not the bottleneck headers can work but in most cases will not add power.

check this link

http://www.ststurbo.com/f_a_q_#27

on sts camaros and vettes the manifolds make more than headers.

 

Twin scrolls have been around for a long time nothing new. You should use a twin scroll tubular manifold with one. This isnt rocket science guys. I dont feel like writing that much to win this manifold argument. So i will just paste some facts.

Part 1

"The result of the superior scavenging effect from a twin-scroll design is better pressure distribution in the exhaust ports and more efficient delivery of exhaust gas energy to the turbocharger's turbine. This in turn allows greater valve overlap, resulting in an improved quality and quantity of the air charge entering each cylinder. In fact, with more valve overlap, the scavenging effect of the exhaust flow can literally draw more air in on the intake side while drawing out the last of the low-pressure exhaust gases, helping pack each cylinder with a denser and purer air charge. And as we all know, a denser and purer air charge means stronger combustion and more power, and more power is good!

But the benefits of twin-scroll design don't end there. With its greater volumetric efficiency and stronger scavenging effect, higher ignition delay can be used, which helps keep peak temperature in the cylinders down. Since cooler cylinder temperatures and lower exhaust gas temperatures allows for a leaner air/fuel ratio, twin-scroll turbo design has been shown to increase turbine efficiency by 7-8 percent and result in fuel efficiency improvements as high as 5 percent.

Combine these benefits with a well-engineered tubular equal-length manifold and the design strengths of a twin-scroll approach can pay even bigger dividends. "Equal length" simply refers to the length of the primary exhaust manifold tubes or runners that the cylinder head exhaust ports breath out into, which should ideally be of equal length before merging at a narrow angle at the collector so that the gases flow smoothly together into the turbine inlet. This helps maintain exhaust gas pulse energy, resulting in better boost response and overall higher turbo efficiency."



Part 2

"It's certainly possible to generate huge power and great high-rpm performance with a single-scroll turbo system. There are plenty of examples of very high-horsepower, single-scroll turbocharged engines out there, but with single-scroll systems spool-up and response are much slower than with a twin-scroll design, yet twin-scroll systems still provide excellent top end performance. Although switching from single-scroll to twin-scroll can be expensive, for hard-core boost junkies who want much faster throttle response without giving up any top end, there is no better solution. With the added benefits of higher turbine efficiency, lower cylinder temps and EGTs which allow more aggressive timing and fuel mapping, and the freedom to run more overlap,twin-scroll turbo system design is really a perfect match for the high specific output engines featured in many of our favorite sport compact machines."


Source: http://www.modified.com/tech/modp-09...rformance.html


I think the big question is does someone make a properly tuned twin scroll turbo manifold. If yes then it is a good modification. If no then its going to perform worse then the stock.

 

I wouldnt consider sts a good turbo system and setup. Its a turbo system made for the ease of installation and not a fully tuned setup.

 

They make power and I have muliple dyno sheets to prove it

 

I just want to check by header you mean turbo manifold. Because I have never heard one referred as a header unless it was an n/a car. But I do know that there would only be one not more its a 4 cylinder.

 

I wasnt saying the dont produce power they do. Just not an optimized system. I think they are pretty good for what they are and they do sound very cool with the turbo in the back of the car. Its a great system for someone who wants instant results via a turbo system with a easy to bolt on solution. But its far from a good system.

The STS turbo systems have the turbo in the rear of the car for those of you that have not heard of them.

 

Just to clarify header manifolds etc...

Headers (headers dont have a turbo. They usually longer runners that are tuned for Naturally aspirated motors)



Twin Scroll cast manifold (these have been around forever! Notice the divider that is what is separating the exhaust pulses)


Twin Scroll tubular manifold(runners are all equal length. Notice the more the divider. Cleaner more separation, and has equal length runners)



Internal shot of twin scroll tubular manifold (you can see proper division of pipes)


Log Manifold(non twin scroll no divider. This solution just mashes all the exhuast pulses together)

 

Does anyone know if there are any vendors even making tubular manifolds. The only one I can find is the ones for the first gen. I do like the supersprint one made for promini's car. It is one of the wildest designs I have seen.

 

Thank you for posting real information here. BTW you twin scroll cast manifold picture is actually not a divided manifold. It is a manifold found on Mitsubishi 4g61/4g63 cars like the Eclipse and Mirage. They have a single volute turbo charger and a very crappy exhaust manifold from the factory.

The heat vs spool thing would be offset by optimum runner size, better collector, and equal length. There is so much that goes into building a good tubular manifold and all of those things make it way better than a factory cast manifold. If you saw anyone lose power on a car by switching back to a cast manifold, they should be pitching a fit to the maker of a crappy product.

 

Lordie some of these pieces are just gorgeous.

I am in love with headers, I admit it.

There a number of very tough problems come together, that matter a lot - so the physics and engineering problems are critical for function.

But the results sometimes are art.

One of the things I appreciate is that a car's intake and exhaust are musical instruments. Some of the same physics applies to the design of pipe organs.

Perhaps it's because I used to play brass as a younger - trumpet and french horn.

I spent a day once in a shop in Petaluma, watching a VERY talented man fabricate a 4 into 1 for a friends 600cc Honda road racer.

The result made power - that thing was at 100 crank horsepower, which for the day was top notch.

But he built it a piece at a time, with incredibly delicate materials and an artist's eye toward what was right. Stitching together many small sections to create the right downpipe length, maximum bend radius, equal length across all four, and all necessary clearances, he still made something beautiful.

Quite a show, and gave me a healthy respect for the workmanship involved.

Sorry for the tangent, I just seem to by lyrical this morning.

Cheers,

Charlie

 

On a small turbo small displacement engine i will stick with what is proven.



For certain normally aspirated or supercharged systems, stock exhaust is somewhat restrictive and can cause backpressure in the system and rob HP. However, with turbocharged applications, the turbocharger is the biggest restriction in the exhaust system. All of the exhaust gasses (except the ones that are vented out the wastegate) pass through the turbine housing. The inlet hole in the turbine housing is about 2"x3", however, as it scrolls around the housing it gets smaller and smaller causing the exhaust gasses to increase in velocity. At the smallest point where the gasses exit and hit the turbine wheel, the hole is no bigger than about 1" in diameter. This tiny hole will create backpressure in the entire exhaust system prior to the turbo and clear back to the exhaust valves.
So sticking larger diameter pipes and high flowing headers doesn't make lots of sense when you have a 1" tailpipe hole. These additions probably won't hurt, but the money would be far better spent elsewhere. Our Turbo Camaro put down 522 RWHP and 620 RWTQ through the same restrictive exhaust manifolds and I-pipe that came stock on the car. Turbocharging is very different than Supercharging or Normally aspirated. That is good news because you don't have to spend the extra money on the exhaust system

 

Thats the nice thing about v8's you dont really need that much boost. A ls1 can make 500+hp on only 6-8lbs of boost.

Yes our lil ol turbo is a restrictive point. But so is any turbo. That is how they function. However increasing the flow to and from the turbo allows the turbo to function much more efficiently.

 

The real trick it to minimize back pressure and reversion via a better exhaust manifold and proper turbine housing selection. I know of people that are still at the magical 1:1 ratio for intake pressure and exhaust back pressure pre turbo and they are running north of 40psi of boost. There are obviously other factors like head work, cam selection, intercooler pressure drop, air intake etc. but the exhaust manifold is an extremely vital component of this system.