yes...........

 

Simple way to explain this is the engine flows more freely. Your increasing the volumetric efficiency and reducing the restriction in the Manifolds. This equals more power but a drop in pressure in manifold.

Bigger cams and porting work in the cylinder head would cause the same effect. Reducing pressure on the intake side with possible increases in Power. Ulitimately you would need to move up to a larger blower that pushes more CFM to see those 20+ psi and you would be making massivling more power at the same boost.

 

Ive asked Rob from Needswings a million questions about the manifolds You only need a re-tune if you get the full replacement manifolds not the tweaked manis but im sure you would squeeze more hp out if you did get a re-tune

 

I know you wanted a "scientific explanation", but there's no scientist here, so I'll give it to you in layman term. You know how when you take a running water garden hose and put your thumb over the end. You've restricted it and built the pressure up and the spray is more intense but there's less volume, same principle as a pressure washer. Yes pressure is part of the equation, but it's the Volume of air per minute that mixes and makes power for us.

 

think of the motor as a big air pump, the more efficently we get air in/out the more power it makes, as a side effect we also get better mpg.

 

Well, I'm sold. Thanks a lot guys, now I have to scrounge up $700 for another mod... way to go.

As always, forum comes through with some great info. Learning more and more every day.

 

I would worry more about running lean with the manifolds than squeezing more power out of a tweaked tune. Before anyone takes the comment the wrong way I am not saying you will run lean just that this is my line of thinking when asked if an updated tune is needed.

So are there any issues with running lean at 120+mph if you add the mani's to the standard batch of mods?

 

I just want to say that I'm 100% impressed with the quality of these tweaked manifolds. And 200% satisfied with the level of customer service. I could not be happier.

THANK YOU ROB!

I am still waiting to get re-tuned for some performance #'s but the estimate is about 15-20hp. I also had the intake pipes coated to match.

Some pics provided in this thread: https://www.crossfireforum.org/forum...tml#post613730

If you're on the fence, I have nothing but good things to say. Get them.

 

thank you for the kind words

i have a silver set on the shelf ready to go

 

Rob, quick question. I have a set of AMG manifolds that I am thinking about being sent to you for tweaking and coating. The previous owner tried to modify them and ended up cracking a weld on the neck when he was grinding it down to fit...oh well. Everything that isn't the feed tube looks in great shape...

What would be the easiest way of paying for the tweaking and coating, seeing as there wouldn't be any core charge.

...also, if I decide not to put these on myself would you be interested in taking them off my hands?

Thanks,
Matt

 

email me a picture of the damage and let's see how bad it is.

 

for any who have not seen the tweaked manifolds here are a few pictures

 

Man.... when will my 'wants' come to an end?

Does anyone know if they will fit with the stock intake?

 

i am using the sl55 intake
i am sure the stock slk's will also fit

 

 

Cores required, right? I have yet to see a 25whp gain after 2 hours of searching!

 

Yes, they charge $500 extra for the cores and refund that when they receive your undamaged stock ones. As far as the gains... The car felt stronger after, but I never made it back to the dyno.

 

my results after a retune did not show a HP gain at the top end, but very fine low end HP and Torque gains. Given the near instant max/flat torque curve I couldn't be happier. For instance, at 2,600 rpm, I was at 170 ft lbs before tweaked/tuned, and 298 ft lbs after installing the tweaked manifolds. Note though, that tweak manifolds were my last mod, so these results are based on having already done the obvious mods to increase top end air flow. The result was VERY evident in traffic. Felt like an electric car w/instant torque.

 

You aren't going to see that, maybe 10 to 15, depending on some other mods.

 

130lbs./ft. At 2,600rpm's is huge, right in the passing range. If we can see this duplicated with others................................