Options and what is worth it.

[BlueDubbinTDI]

Originally Posted by Fast_Freddy

Let me get this straight... A header + tune that gains 30 whp is a bad tune???

205+ whp should be expected from just a header and e85???

Seeing as how just an e85 tune makes ~193whp and catless headers used with about any tune makes about 8-10 by themselves ide say very possible.

[StormTrooper]

I forgot the e85 in the first part... Meaning header with e85 w/ custom tune should easily break 30whp added. Since its been done multiple times on 91/92 octane.


So if we assume 165 stock baseline then 195 with header and tune ..205 with e85 added.

[forzajuve]

Thanks for your input man. Why do you prefer/suggest an EL header over a UEL header? I am not understanding the technical difference/benefit of EL vs UEL... other than sound output.

[boredom.is.me]

EL vs UEL
http://www.ft86club.com/forums/showthread.php?t=49638

[AspenItIs]

Originally Posted by boredom.is.me

How would it be silly? When they post dyno plots of the various FI, it is typically with the stock exhaust components. Also you spend ~$5000 to get more power than you ever could with any amount of bolt-ons. Why should you be obligated to spend another $1000-$2000 on just an exhaust.

Because N/A exhaust design is the complete opposite of FI exhaust design. why would you invest that much in something only to complete the bare minimum? Ask Crawford if they used the stock exhaust for their 450hp BRZ.

Here's a good read on exhaust theory written by a Turbo Systems Engineer at Garrett.

"N/A cars: As most of you know, the design of turbo exhaust systems runs counter to exhaust design for n/a vehicles. N/A cars utilize exhaust velocity (not backpressure) in the collector to aid in scavenging other cylinders during the blowdown process. It just so happens that to get the appropriate velocity, you have to squeeze down the diameter of the discharge of the collector (aka the exhaust), which also induces backpressure. The backpressure is an undesirable byproduct of the desire to have a certain degree of exhaust velocity. Go too big, and you lose velocity and its associated beneficial scavenging effect. Too small and the backpressure skyrockets, more than offsetting any gain made by scavenging. There is a happy medium here.

For turbo cars, you throw all that out the window. You want the exhaust velocity to be high upstream of the turbine (i.e. in the header). You'll notice that primaries of turbo headers are smaller diameter than those of an n/a car of two-thirds the horsepower. The idea is to get the exhaust velocity up quickly, to get the turbo spooling as early as possible. Here, getting the boost up early is a much more effective way to torque than playing with tuned primary lengths and scavenging. The scavenging effects are small compared to what you'd get if you just got boost sooner instead. You have a turbo; you want boost. Just don't go so small on the header's primary diameter that you choke off the high end.

Downstream of the turbine (aka the turboback exhaust), you want the least backpressure possible. No ifs, ands, or buts. Stick a Hoover on the tailpipe if you can. The general rule of "larger is better" (to the point of diminishing returns) of turboback exhausts is valid. Here, the idea is to minimize the pressure downstream of the turbine in order to make the most effective use of the pressure that is being generated upstream of the turbine. Remember, a turbine operates via a pressure ratio. For a given turbine inlet pressure, you will get the highest pressure ratio across the turbine when you have the lowest possible discharge pressure. This means the turbine is able to do the most amount of work possible (i.e. drive the compressor and make boost) with the available inlet pressure. "

[boredom.is.me]

My only point is that not everyone wants 450whp. I should have specifically stated that. I personally wouldn't want to go above 250.
I'll read what you have a little later when I have some free time.

[boredom.is.me]

@AspenItIs
So I read your little quote, but it only discusses exhaust in a turbo charged application. Isn't it safe to assume that a supercharger would also benefit from the same things (back pressure) a normal N/A would benefit from? Based on what you have above, boost by turbo is a function of exhaust velocity up to the turbo itself. Meanwhile, boost by SC isn't a function of velocity. It is a function of rpm, so finding the ideal exhaust diameter would be the same as finding the ideal diameter of an N/A. Yes or No?

[kombatlion]

Ok I will join this debate jajaja.
I have full exhaust, overpipe, no cat, no header and Greddy Intake no Tune 161whp on dynojet and 171 on dinomite... weird right?

Now I will tune soon and maybe I will see a decent dyno graph on Mustang, then I will go back to Dinojet and compare.

If I dont get 180whp I be very pissed!!

Here in Puerto Rico there is no E-85 And I want to get to 200whp NA there is 93 and 100 octane. Like I said 200whp Aspirated enguine will make me happy but nobody have been there yet with bolt ons an no E-85.

[forzajuve]

I am with you as well. Like you, I am only looking for a modest boost upgrade. 450 whp is too much for what I will be using the car for. i.e. predominantly a daily driver. As you also said, around the 250 whp would be perfect, heck even 220-230 whp would be really nice as a DD.

[AspenItIs]

Originally Posted by boredom.is.me

@AspenItIs
So I read your little quote, but it only discusses exhaust in a turbo charged application. Isn't it safe to assume that a supercharger would also benefit from the same things (back pressure) a normal N/A would benefit from? Based on what you have above, boost by turbo is a function of exhaust velocity up to the turbo itself. Meanwhile, boost by SC isn't a function of velocity. It is a function of rpm, so finding the ideal exhaust diameter would be the same as finding the ideal diameter of an N/A. Yes or No?

This theory is for Turbo applications, can't comment on superchargers. But i disagree with your statement, boost is a function of your right foot!

[Fast_Freddy]

Originally Posted by BlueDubbinTDI

Seeing as how just an e85 tune makes ~193whp and catless headers used with about any tune makes about 8-10 by themselves ide say very possible.

You can guess and say whatever you want but the facts do not support your conjecture.

Originally Posted by StormTrooper

I forgot the e85 in the first part... Meaning header with e85 w/ custom tune should easily break 30whp added. Since its been done multiple times on 91/92 octane.

So if we assume 165 stock baseline then 195 with header and tune ..205 with e85 added.

You didn't mention e85. You said "Header and tune and only 30whp...sounds like a bad tune". Personally I think that you are wildly optimistic with your whp estimates. Maybe you meant to say that a header (+ full exhaust + intake) + tune = +30whp (~195whp for MT, in Dynojet equivalent figures, of course).

[AVOturboworld]

Originally Posted by forzajuve

Vortech - $5,687 - +132 whp

If you took the Vortech figures off their page, you should read them a bit more carefully. Their quote of 294hp is just that - hp, not whp.

So you need to either multiply all the other figures by 1.18%, or subtract that from the Vortech figures. For instance, we made 275whp on a stage 2 kit, so that ends up being around 325hp.

[StormTrooper]

Originally Posted by Fast_Freddy

You can guess and say whatever you want but the facts do not support your conjecture.



You didn't mention e85. You said "Header and tune and only 30whp...sounds like a bad tune". Personally I think that you are wildly optimistic with your whp estimates. Maybe you meant to say that a header (+ full exhaust + intake) + tune = +30whp (~195whp for MT, in Dynojet equivalent figures, of course).

Like I said I forgot to add e85 in my first post. Don't be an ass. Also intakes on this car are useless

[BlueDubbinTDI]

Originally Posted by Fast_Freddy

You can guess and say whatever you want but the facts do not support your conjecture.



You didn't mention e85. You said "Header and tune and only 30whp...sounds like a bad tune". Personally I think that you are wildly optimistic with your whp estimates. Maybe you meant to say that a header (+ full exhaust + intake) + tune = +30whp (~195whp for MT, in Dynojet equivalent figures, of course).

Oh no?

Before header and ~205 after....