Kane

iTrader: (1)

In that case - screw it.... throw the Engine Dyno on the plot then.... It is likely to be as accurate as all the stuff up there now. I mean engine mileage, compression, ignition, temp, humidity..... you get the idea; means that I can dyno my car on two different days and gain or lose 20-30 HP over 6-10 pulls.... actually more with my old bad ignition.

And I know that for a FACT.

paulmasoner

iTrader: (1)

MARKETING... thats all it is. sure, we have created a spot to post all the plots in one convenient place to view/compare them.... but the plots would exist even without the threads. its a means of a manufacturer promoting superior products.

rotarygod

Hymee has at least given a reference to what he measured on a stock engine. I care about the amount gained, not the actual number.

Brettus

iTrader: (2)

weeeeeeee dogggggy !!!!!

paulmasoner

iTrader: (1)

yes, and THATS what matters. but the way this thread is percieved, and the way i think most people look at this stuff.... eh, you get where i'm going i know

rotarygod

Since this thread is being debated and it's understood that it's all marketing bs, is there really any relevance to which does which on paper compared to another anymore? There shouldn't be if everyone here is smart enough to know it doesn't matter! There is absolutely NO basis for saying one manufacter has a superior product based on what a dyno chart tells us. It's wrong to imply as such. It's clear who has the superior product anyways.

paulmasoner

iTrader: (1)

eh, i quit. RG, i know this. and i even agree with you on the superior product bit. i'll drop it with one thought: how many people viewing this thread or any other collection of dyno plots from all over the web view and understand what the plots mean in the same way you do?

Brettus

iTrader: (2)

Let's face it -the dyno is the best tool available to compare the outputs from various systems . If we could do engine dynos on all the kits it would be an even better comparison . But to say what is presented on this thread is useless is wrong . It is usefull information - some uneducated people will just look at the biggest number and say to themselves "that is the best kit" others of us who actually go a bit more in depth will look at more than this .

But : the plots are still usefull !

Hymee

iTrader: (1)

Like I started out in my original posting - a dyno chart comparing the same engine in naturally aspirated and supercharged form on 2 different fuels... A simple baselined comparison, with nothing to argue about, nothing to confuse things, just relative comparisons. You cannot do more than that. It doesn't matter what the drivetrain losses are, how hot or slippery or viscious various gearbox oils are compared to others, how well the **** end is strapped down, how much frictional losses there are on the rollers - all of that is negated by the fact that the same tests were run on the same equipment and same engine and I even overlayed an independant engine run on equivalent equipment (superflow). Folks, I am comparing apples to apples, and I'm not trying to confuse anyone.

The biggest confusion here is the fact that those "WHP" charts are not showing actual WHP at all.

Cheers,
Hymee.

RIWWP

iTrader: (2)

I can see RG throwing his hands up in frustration... I also see that he is resisting the call to cater to ignorance. I agree as well, people don't read and don't analyze, they don't research and don't seek to understand. They want that dumb boiled number. I agree with what your saying Paul, but I don't think it should affect what we put up

I agree that you should refuse to give it to them. Make them research and they will be better for it. Don't make those correction factors for ignorance in what you post, it only makes things worse in the end.

rotarygod

I'm not trying to argue with you. I know you fully understand all of this. I'd like to hope that anyone who is able and willing to drop thousands of dollars on a forced induction kit is smart enough to do their homework and actually learn how things work. I'd also like to think that anyone reading this thread is smart enough to understand what is being said so they can take everything with a grain of salt. There will be people who only care about what number is printed on a piece of paper. Fortunately those probably aren't the people who are going to be buying anything so why appease their limited understanding?

For any true comparison to be made in terms of power, each should meet a couple of requirements and this is the hard part. First off a baseline power run on a stock, unmodified engine be performed on the same type of dyno. Second, an overlay of the results of the forced induction kit's results using the same type of dyno. The result should be indicitive of what a buyer should expect and not be tested with gimmicks such as octane boosters, intake manifold icing, race gas, higher boost than the kit comes with, water injection, etc.

When you have this info, the type of dyno used becomes irrelevant. Even the actual horsepower numbers become irrelevant as the only thing that each will show will be percent gained over a stock engine. That's what matters. That's what people care about. That's what moves you. You can extrapolate vs others to your heart's content this way.

I fully understand that there are people out there that only are about what ultimate number any particular kit can give. Not to sugarcoat it but they're idiots! Most likely few if any of them will realistically be purchasing any of these systems anyways. The few that do are only going to buy the cheapest which will be the Greddy. Then they'll be sad and finally be forced to face the reality that there's more to a kit than price or a boost number. Why on Earth should we care what they think? We shouldn't. If there's one thing I've always supported, it is educating the masses away from the brain washing marketing ploys and misconceptions that are so frequently believed to be fact and portrayed as such. The sad fact is that this philosophy may or may not work against the agenda of some of the kit makers/sellers. I don't care! If these are the people that irrelevant plots and comparisons should be made for, why not just crank up the boost on all of the kits, add race gas, ice down the intakes, add water injection and see what they can all ultimately do? It's just as accurate a comparison to the real world that way as anything else that isn't comparable.

jujo

You ever get around to Dynoing? Notice any difference after the coil change?

shaunv74

+1. Chiketd. How did your dyno runs go?

chiketkd

iTrader: (5)

Yes. No real difference afterwards as the coils I took out looked as good as the ones I replaced. My car was built late in the 2006 MY, so I'm guessing my car got the updated coils. However, it's hard to say if the coils truly had no effect, as the car wasn't 100% afterwards.
It was a "learning experience" as my car wasn't running at 100% when I dyno'd it.

I took my car to the dynojet on Saturday, with a vacuum leak that I wasn't able to fix beforehand (repalcement part was still on the way). Last weekend when changing out my coils, I removed the airbox and broke off a vacuum line in the process.

On the dyno, my car made 164.4hp and 129.8wtq. Peak power was reached at only 7,200rpms and the curve became flat afterwards. My afr's were monitored, and in "open loop" they varied between ~11.9-13.5.

The dyno shop had a low mileage bone-stock '05 6MT on their dyno previously, and that car made 179hp and 127tq.

shaunv74

You're losing something up top. Your power peak should be at 8krpm or so. I guess the vacuum leak could be part of the problem.

Other thoughts are clogged cat. or plugs and wires. Can you post up the dyno sheet.

chiketkd

iTrader: (5)

Dyno sheet can be seen below...



As we've discussed previously, my spark plugs, plug wires and coils are all brand new. I doubt the cat is clogged as this car is autocrossed quite a bit and taken to redline often - but who knows. The owner of the dyno shop also felt my varying afr's in open loop indicated air getting in after the MAF. He felt that b/c my car made more wtq than the otehr RX-8 they dyno'd, it indicated my engine was healthy, something was just not working like it should in the 7-9K range.

P.S. Parts were actually waiting for me when I got home, so I replaced the vacuum line and fittings today. However, 5-8" of snow are coming down right now, so I won't know how the cars "feels" until Tuesday/Wednesday at the earliest.

jujo

Ahh, that's too bad. You did make more torque though! Indicating potential
Looks don't really mean much when it comes to coils though. How many miles on your engine?

Yes... I'm looking out the window and definitely not going to work today

You know, now you're going to have to help me with the BHR coil install later this month Let us know how she feels when the roads clear up.

chiketkd

iTrader: (5)

My engine has 45K miles. You know, looking at my power and torque curve up to 6K rpms, it was actually looking pretty solid for a stock car. I was definitely ahead of the car that dyno'd at 179 - so I'm guessing my peak hp should have been somewhere in the mid 180's.
Drove my wife's lancer into work today. Definitely leaving the RX-8 parked for most of this week.

I'll have to see as I'll have autcrosses on 5-6 weekends. I'm also not sure if I'd trust myself with someone elses car as I broke off that one vacuum line on my car - even though I now know which lines are safest to pull.

shaunv74

Let's hope it's the vacuum leak. It looks pretty healthy until after the last intake runner opens up and then it just dies off. My only other thought is clogged cat. as the power loss can vary depending on the health of it. I've seen much worse for a clogged cat though.

chiketkd

iTrader: (5)

How are these intake runners activated? If they open from engine vacuum, that might explain the high rpm power loss.

Also, would the afr's jump around like that with a clogged cat? My thought is that the afr's should look reasonably normal, but the car would just lose power up top. I'm thinking I'll take the car back to the dyno sometime in mid-to-late April. By then she'll have 4-5 autcrosses and hopefully any winter soot in my cat will be blown out!

I do plan on building the car for STX this Fall and my plan is to install the Fluid Motorsports header and the RX7store mid-pipe w/ high flow cat. So a new cat (highflow) will be in this car in about 9-10 months.

Hymee

iTrader: (1)

The "6-port" valves (APV) are electrically operated.

The VDI valve that shortens the effective runner length is vacuum operated, as is the SSV (4-port) and VFAD. The VDI and SSV vacuum comes from a small tank that holds vacuum like a reservoir and a check valve to hold retain it when there no manifold vacuum. The VFAD vacuum is done similarly through a separate tank and check valve.

Cheers,
Hymee.

chiketkd

iTrader: (5)

Hymee,

Many thanks! You are absolutely correct and the parts diagrams I've been looking through for the last hour confirms this.

In the attached image, the grey circle around the middle of the page shows the "vacuum chamber" where I had broken off a vacuum line completely (I placed electrical tape over the openings to keep large dust particles out). The grey circle at the bottom of the page shows the Fresh Air Duct (FAD) which these vacuum lines control. With that vacuum line completely disconnected, the FAD would not have opened at 7,250rpms on any of my dyno runs - which explains the 7-9K portion of my dyno graph.

I'll definitely take my car back in a month and re-dyno. Thanks again Hymee.

shaunv74

Or you could just remove the VFAD.

Flashwing

It's also important to note that the "smoothing" setting on your dyno sheet is set to Zero. So, you're going to have more of a heart attack look to your dyno plot.

I'm sorry if I didn't understand this exactly, is the dyno sheet you posted with a vaccum leak? You said you dyno'd with one but I didn't see for sure if the sheet you posted was without the leak or not.

Here's something to look at:



Granted, the smoothing setting is on 5 on this dyno, but you could see where it's possible that it would look almost exactly like yours except yours simply is making less power. The plot itself looks right, it's just not as high as it should be.

This dyno was done with fresh plugs/wires and new coils as well. Only difference would be mods and tuning.

chiketkd

iTrader: (5)

Unfortunately that's not legal for my autocross class. I need to keep the system in place.
Flashwing, the dyno plot I posted was with the vacuum leak.

I got to dyno the car for just $55 as part of a group dyno day. I didn't want to flake on my group, so I went ahead and dyno'd the car even though she was not running at 100%.