rotarygod

Who the hell are you and what's your problem? I HAVEN'T BEEN ONLINE!!! Give me a break. Seriously, I've got to know, what was so offensive about what I said? Seriously? Why was it so bad? I made no personal attacks. I just told a story. I have never seen someone get so pissed off over such a simple thing. Get over yourself. You don't have to believe anything I say. I don't really care!

BTW: You're about to get banned again.

DOMINION

I agree the pissing match must stop. Say your piece and dont try to change peoples religion
I for one am not being "protagonist" to RG. I'm just saying if you drive a 200hp car and a 300hp can you feel the difference?
You ban me and I call Ike

Mikeluvs8

WHO POSTED NISSAN VID'S???

rotarygod

I guess it was a Honda. Sorry. I thought it was for an SR20 not a K20. I'm not too up to date on other manufacturer engine codes. The K20 is a Honda isn't it?

Mikeluvs8

Yes Sir!!!

DOMINION

PM sent

AlexCisneros

so the OBX header doesn't make power and I shouldn't believe everything I hear at Barnes and Nobles?

DOMINION

Well I asked Mike if he would like to Dyno his BPU N/A MT 8 vs my bone stock MT 8 and he agreed This will be on my expense.
Now we will sit back and let the theory's and myth's speak for themselves.

flip702

^ Gil... when is this going down? I wanna see!

DOMINION

Give it a week. We need to get the same days off. PM sent...

BoosTED

iTrader: (2)

Something good will come from this.

rotarygod

Since RX-8's don't dyno consistently against each other it won't really tell us how much of a gain was to be had by any particular mod compared to the other car. What it will show us is the power level of each car.

I'm going to write another tech article in the immediate future called "ricer logic" (not aimed at you guys) so people understand how gains can and do work on cars and how mods add up.

DOMINION

Back on topic! I'm due to place my order for the OBX Header in two weeks (payday). Cant go wrong for the price. Then another Dyno.
Every BPU mod will be followed by a Dyno. Let see how well my 8 holds up
I'm also following the most comen steps in the likes of Turbo Superstreet ect mod/Dyno sections.
Why not have fun if your going to mod

Vegaz_Nightz

let me know when you go dyno Gil.. I wanna dyno mine.. all I got is the intake.. about how much is it?

Vegaz_Nightz

thats true RG.. every engine is different but nonetheless its the same engine design.. I understand you won't get exact numbers.. but you will get an estimate.. and an estimate is all you need to give you an idea..

rotarygod

Believe me I'm not saying don't do it. I think it would be interesting. What I do want to caution people over though is through the way they estimate how much power they are going to get based off of individual mods. We've seen stock engines dyno at 200 rwhp and we've seen modded ones dyno less than this. That's why I feel it's going to be inconclusive. Give a call to Racing Beat or Speedsource sometime to see what kinds of gains they've had with various tings. Keep in mind they do hundreds of dyno runs in contolled conditions with the same engine to see what works and doesn't. RB has actually confirmed through dyno testing that exhaust gains are not cumulative based on their individual totals. I don't care if anyone believes me or not and unfortunately they never release their dyno charts but they have stated this before.

There is alot to think about when it comes to gains that each mod does. Engine design, how well it breathes from the factory, overlap, etc all come into play. Sometimes you will find a couple of mods that actually add up to greater than the sum of their gains. This happens on high overlap engines such as peripheral port engines. Other times you don't get this such as engines with little to no overlap. Because there is no one way to figure this out for all engines, a comparison against other types of engines becomes irrelevant. It's also very hard to compare the same type of engine when that particular engine has little consistency to it.

I'm all for dyno's of various mods. I feel that 5 runs should be done for each setup and then averaged together to get a baseline. For each test intake and coolant temps need to be as close to each other as possible. Tire pressure must remain equal etc. There's far more to getting an accurate way to compare mods than just taking 2 cars to a dyno, strapping them on, and getting numbers. This isn't accurate unless other things are learned first. Did both cars dyno the same when stock? Are they both running the same type of oil? Are they running the same tire pressure? Same types of tires? Same coolant and oil temps at the time of test? This is why I don't trust the average person's comparisons with a dyno. If they take all of this into account then they've got a chance.

Keep in mind the best way to get a comparison on a dyno is to do the aformentioned 5 runs stock. Then do 1 mod and again do 5 runs. Make sure all of the above listed things are as close as possible to ensure consistency. Restore the vehicle back to stock and install the nect mod by itself. Again do 5 runs. Repeat the process for as many mods as you have. They finally install all of them and repeat. Yes this would get expensive. Yes this would be alot of work. Yes this would take a long time. Now you know why people like RB and others do so many runs. It's the only way to get any accurate comparisons for what works, what doesn't, or by how much. Merely showing up to a dyno with 2 cars and doing a run for comparison sake tells nothing important. Dyno's are great for selling products though and companies rely on the fact that the average person will believe one dyno chart.

If you really want to get good information, you'll dyno all of the above at multiple set throttle load levels for information as to what happens in other driving conditions. This way you aren't only getting full throttle information which doesn't really tell you much when it comes to street use. This is why a dyno is nothing mroe than a tool and not an absolute fact generator based on each individual run.

Vegaz_Nightz

certainly not accurate.. or official.. but I'll say this.. Curiosity killed the cat.. .. and its curiosity that drives most people into doing something to get a solution.. even if the solution isn't the proper way.. once again curiosity!!

all I'm saying is.. even if something isnt accurate or perfect.. all of us want one thing.. To be happy!! and if something makes Joe Smoe happy.. then let em be happy.. so what if it isn't the correct way.. what matters in life, regardless... is our happiness

the only thing I see everyday.. are people who are envious of others happiness and try to tear it down.. (note: this is not directed at anyone.. just a statement)

Everyone enjoy your 8 and be happy with it....

SolarYellow510

This is where DOE (design of experiments) can get tricky. When I look at a dyno plot, I look at more than the peak number. Generally, smoothness or lack of it will tell you quite a lot about how an engine is running, and there can be significant run to run variation. When you start averaging multiple runs together, it automatically smooths the plots, making the tune look artificially good.

As much as it's non-ideal, my strategy has been to get three runs acceptably close together (repeatability - I want to see within ~1.5 hp for three runs, or tighter), then report the middle one, unless there are some aberrations in the curve. That way, I'm not distorting the "subjective" elements of the curve by processing it.

With computer-controlled cars, I've found if the coolant and intake air temps are at the same point at the start of each run, the results will usually lie right on top of each other. I try to get out on the freeway and see where these stabilize at cruise, and use those numbers as targets for the dyno. Managing heat flux out of an intercooler adds a whole 'nother level of complexity and room for debate and fingerpointing.

Haven't dynoed RX-8s much yet.

brillo

any typical tuner mag (modified, sport compact car etc....) will tell you that HP gains from single mods to a car don't aggregate 90%+ of the time. Its just a known commodity. I'm sure there is an exception, but I'd put money on that fact of car tuning if I had to. I can't believe that concept is even debated anymore.

lepichichi

iTrader: (10)

Here is my 2cents, i had the OBX headers in my car for 6 months now and i really havent notice any power gains or loss gain, the header is much lighter than stock and it doesn't heat up my engine bay so overall not bad for its price, i do have a engine light cell after installing my headers and agency power muffler, I'm running stock converter so i'm taking it next week to the dealer to clear the light, i will keep you guys updated!!

AniZckN

hi my name is Nick and i just recently start wanting to hook up my rx8 ..i found your message on here and i wondered if you can help me to see what kind of parts would go great with my rx8 .. i looked at the cat backs and mid pipes but they cost around 600 .. is that a good price? and which ones do you recommend? sending a link would be best .. thank you.

BoosTED

iTrader: (2)

There are numerous threads on parts reviews Nick.

Use the search button in the top tool bar on the site it is your quickest way of finding the information you want to help you decide what is best for your car.

stuartm

Dyno the stock car & the modded car. Then swap the aftermarket parts to the stock car & use the oem parts & stick them on the modded car. Dyno the cars again, this will remove the inconsistency between the cars & reveal if the mods do what they say.

Cromax

Whoa!!! This thread has been going for over 3 years!

After reading the whole thread, I've decided against getting headers for the following reasons:

1. The people who have posted up results have had minor to no horsepower improvements or,
2. Other mods have been done at the same time.

Unless Dominion has a different opinion?

olddragger

iTrader: (3)

it would be wise to wrap them--under sustained wot(like a dyno) the headers will glow red hot.
OD