Today I went to get my car re-tuned since installing a hondata gasket and JG Edelbrock Manifold. At 11 psi, I made 250 hp and 203 lbs torque (sorry no graph). Right before we dynoed, the tuner stated that I would be losing power with that manifold because the plenums are too big and will be not effective unless you run 20 or more pounds of boost. He stated he has tested this on the dyno and it is proven that you will lose horsepower. I am assuming this is true because before I had a stock gsr manifold and dynoed my car (1 year ago) and I got 260 hp and 190 lbs torque given this was on a different dyno jet. The question is am I really losing power through this manifold?

BTW my setup is:
B18C1
Greddy turbo kit
Inline pro headgasket
STR Cam Gears
450cc injectors / vafc / FMU


Modified by Andrew 825SM at 8:15 AM 9/24/2003

 

yes

 

Makes sense.

A tiny turbo, low boost, what did u expect. It's massive, maybe if you step up to a t3/t4 and 12-14 psi you'll break even. I know people who have made tons of power on them with bigboy setups though. I'm actually going to be running one on my All Motor setup.

 

I don't see how it could make less power at the same boost pressure. As long as its flowing more air it has to Make more power. Thats like saying going from 2.25" piping up to 2.5" will cost you power. It might take longer to spool but its not gonna cost any power.

 

He isn't lying, that is one of the biggest assumptions that it WILL make more power - only if you have the air to shove down it

 

The puny turbo can't create enough cfm to through down the big *** throat that you installed. Don't make me use the squeezing of the garden hose example thats been played out!

 

It's not the amount of air, its the quality of the air flow, and if you dynoed a year ago on the same setup, its not a fair comparison, you could have lost 10hp though the rings or valve seats in a year. I'd like to see a back to back.

 

If your making 10psi in the manifold now and before then you still have 10psi of air there to feed into the valves. it should make more power. If you have a good reason why please explain... I'd like to hear this garden hose theory.

 

Ok I just reread that. He would not lose power if the turbo was maxed out at the old flow.. He just would not make anymore. I don't think he was maxed out before though.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Overblown-Teg &raquo;</TD></TR><TR><TD CLASS="quote">I don't see how it could make less power at the same boost pressure. As long as its flowing more air it has to Make more power. Thats like saying going from 2.25" piping up to 2.5" will cost you power. It might take longer to spool but its not gonna cost any power.
</TD></TR></TABLE>

Increasing the flow capacity kills the flow velocity. Thats the same reason that throwing on a 70mm throttle body on a stock motor will kill the power. Unless its matched with the right setup, you will only lose power. Exhaust flow and intake flow are not good things to compare.

 

I meant intake charge pipes. I know your gonna love this but with boost you don't need to worry about anything but having the biggest runner possible to get allow the air to ram into the cylnder. Here is my example. You have a nice big tire.. This will be our boosted plenum.. you poke a hole in it.. this is the stock runner and valve. The air comes out. Now you take the same tire with the same air pressure and cut a 3" hole in it. The air goes out alot faster. That is like the big intake. The only restriction you have then is the valve.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Overblown-Teg &raquo;</TD></TR><TR><TD CLASS="quote">I meant intake charge pipes. I know your gonna love this but with boost you don't need to worry about anything but having the biggest runner possible to get allow the air to ram into the cylnder. Here is my example. You have a nice big tire.. This will be our boosted plenum.. you poke a hole in it.. this is the stock runner and valve. The air comes out. Now you take the same tire with the same air pressure and cut a 3" hole in it. The air goes out alot faster. That is like the big intake. The only restriction you have then is the valve. </TD></TR></TABLE>

Wrong, bigger hole = lower air velocity. That may not sound important to you, but when air velocity gets low enough you won't be filling the cylinders up all the way.

 

Inaccurate test because they were not on the same dyno. Also, you put a years worth of wear and tear on the motor so you could have lost a little bit from that as well. Like they stated on this manifold, it is designed for high rpm 7,000-10,000rpm range improvments. So if you are not looking to improve hp in this range, the mani. should not be run unless you want to save 7 pounds over the stock gsr mani.

 

Look at how much power boosted hybrid is making on his stock gsr with that intake manifold.. He put down 350whp at 12psi??? Maybe you need a new tuner that knows what he is doing.

 

You should be gaining some power from ~7K and up.... the tuner was correct if he meant that you would be loosing more area under the curve throughout the entire torque curve....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Overblown-Teg &raquo;</TD></TR><TR><TD CLASS="quote">Look at how much power boosted hybrid is making on his stock gsr with that intake manifold.. He put down 350whp at 12psi??? Maybe you need a new tuner that knows what he is doing.</TD></TR></TABLE>

Jeff is a master hondata tuner too. Is this guy running hondata? I'm betting he's not.

 

No he is running the vafc hack.. But don't blame a manifold for his bad tuning. I can't wait to get my jg manifold and test it.. I'm willing to bet that Jeff is making more power under boost with the jg intake than with his stock gsr one. Any rpm under boost.

 

When you are selecting an intake manifold that is currently produced you have to determine where you want your peak torque to be. The skunk2 is more suited towards the 8K redline, the eldebrock is more suited to a 9k redline. By the shear definition of horsepower, the higher you can carry the torque the more peak horsepower you'll make. The eldebrock does just that, it carries the peak torque higher to give you higher peak horsepower gains. Intake manifold geometry has some effect upon the air velocity, but more importantly it has a greater effect upon the frequency dampening charaterisitcs. The frequenices that build up on the intake stroke of the engine that are bounced back inside the intake manifold can create bottle necks, slowing down the airflow far more than the geometry could dictate. You could the theoritical optimized shape for an intake manifold, but unless you have analzyed where you want your frequencies minimized called Helmholtz tuning peaks, you wont make very good power. In general the volumetric efficiency of the engine will suffer greatly due to the frequencies, effecting both horsepower and torque. The aftermarket intake manifolds may consider this, and may not. In reality the intake manifolds on the market, excluding the air search/endyn are not engineered using frequency analysis. I just want to illustrate that there is much more behind the simple geometry of an intake manifold that will effect power production.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Overblown-Teg &raquo;</TD></TR><TR><TD CLASS="quote">No he is running the vafc hack.. But don't blame a manifold for his bad tuning. I can't wait to get my jg manifold and test it.. I'm willing to bet that Jeff is making more power under boost with the jg intake than with his stock gsr one. Any rpm under boost. </TD></TR></TABLE>

No I am not running the VAFC hack. I am running the inline pro setup which consists of a vafc, intank pump, fmu, and 450cc injectors. There is no partial throttle hesitation and I think my car runs fairly well with this setup. A/F ratio was around 12-12.5.

 

I still think you should be making more power.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boosted hybrid &raquo;</TD></TR><TR><TD CLASS="quote">When you are selecting an intake manifold that is currently produced you have to determine where you want your peak torque to be. The skunk2 is more suited towards the 8K redline, the eldebrock is more suited to a 9k redline. By the shear definition of horsepower, the higher you can carry the torque the more peak horsepower you'll make. The eldebrock does just that, it carries the peak torque higher to give you higher peak horsepower gains. Intake manifold geometry has some effect upon the air velocity, but more importantly it has a greater effect upon the frequency dampening charaterisitcs. The frequenices that build up on the intake stroke of the engine that are bounced back inside the intake manifold can create bottle necks, slowing down the airflow far more than the geometry could dictate. You could the theoritical optimized shape for an intake manifold, but unless you have analzyed where you want your frequencies minimized called Helmholtz tuning peaks, you wont make very good power. In general the volumetric efficiency of the engine will suffer greatly due to the frequencies, effecting both horsepower and torque. The aftermarket intake manifolds may consider this, and may not. In reality the intake manifolds on the market, excluding the air search/endyn are not engineered using frequency analysis. I just want to illustrate that there is much more behind the simple geometry of an intake manifold that will effect power production. </TD></TR></TABLE>

Nice post. Now I have to try to understand it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jared &raquo;</TD></TR><TR><TD CLASS="quote">It's not the amount of air, its the quality of the air flow, and if you dynoed a year ago on the same setup, its not a fair comparison, you could have lost 10hp though the rings or valve seats in a year. I'd like to see a back to back.</TD></TR></TABLE>

exactly. and you cant compare two different types of dynos either.

there is a lot of diff things that can happen in 1 year.