*DYNO POSTED*

After a good 1.5 hour trek from Fort Worth to Garland Texas, I finally made my way to Rotary performance to install my HF cat and do a little dyno tuning of my Mazdsport Interceptor-X. I should preface all this with the fact that it was hot as all hell today, so in spite of fans and shade, I have to believe 100+ ambient air temps have an effect on your numbers. All dyno’s were done in 4th gear with 87oct. My base line with the RB Intake and HF cat (have the stock exhaust) was 182.6WHP. With the interceptor-X, We managed 188.3WHP. Attached is the dyno chart.

Needless to say I was hoping for more, thinking 190’s would have been nice. We did manage to dial the Interceptor-X in well for idle/cruise etc….its running in the mid 15’s at cruise and idling in the 14’s. The A/C is still giving me some idle issues but I’ll figure that out soon. The point is I got some mid range gains, and the car drives without surging, hesitation stalling etc…I had to leave the car after an hour of driving up in Fort Worth to fly home, which sucks, b/c I really want to play with it now.

Some random observations:

-We disconnected the stock wideband to connect the dyno wideband. The car seemed to idle at a higher RPM (around 1,100) as a result. I thought this was interesting.

-The car seemed to make the most power as you can see hovering around 13.2 afr
-It took a hell of a lot of dyno runs (even with the stock wideband disconnected) to throw a CEL.

-The HF cat with the stock exhaust is virtually silent, only on certain occasions can you hear the sound, and it doesn’t ever drone.

-The exhaust hanger that is holding up the group buy is not totally necessary. You can adjust the power plant frame to raise the whole exhaust system higher to clear the tranny braces. I do her a slight noise if I hit a really hard bump, but just driving I here no vibration at all.

Tuning the car NA with the interceptor will take some work, its not drop in and your ready to go with 20+ HP. Each car does need to be dialed in slightly differently. I bought the unit with an eye towards FI, so they is a good way to get my arms around the ECU and learn the tuning process. I may look at light weight exhaust options now in the future, and see if I can hit 200WHP NA.

I'll post my screen shots here as well, maybe there is some power missing you guys can help me find.

 

Nice write up. Your peak power wasn't that great, but I think it was the same when Scott was doing the original tune. I'm interested in how much power you made in the midrange areas.

 

hey Brillo,

next time you do a dyno run I would suggest going with the premium pump gas a time or two before you do a dyno run. I don't know about others expeirences but if i run the cheap shitty gas i do notice my car isnt as happy, on several occassions under hard acceleration i got what appeard to be some knock and ping.

I only use Shell V-power or Chevron Premium, I figure for all the money i've spent on the car spending an extra 3 dollars per tank for premium isn't a big deal.

There is an episode of Fifth Gear that tested this theory of Regular Vs. Premium gas and they found that for "high performance" sports cars.

They found that for econobox cars it doenst matter what you put in, you get the same power across the board.

However for a Golf GTI they tested
Cheap Gas: 172BHP
BP Ultimate Gas: 174BHP
Shell Optimax: 177BHP

(nothing spectacular i agree)

for a Subaru STI
Cheapo Gas: 235BHP
BP Ultimate: 248BHP
Shell Optimax 249BHP

(nice difference there)

Their testing methodology looked sound too, they did it on the same dyno on what seems the same day, drained the fuel tank after 6 runs each to get avg results, and then reset the cars ECU between each gas grade to make sure things were fair each time.

I'd love to see a dyno after you get the car 100% tuned and stick a tank of premium in there a few times in row before you go

 

The octane issue has been debated and beat to death many times on this forum. He should be just fine with the 87.

 

were those SAE corrected numbers or uncorrected?

(188.3 uncorrected would correct to 203hp if it was 100 degrees out)

 

I am a firm believer in using the same grade of gasoline that you drive around with. The stock ecu doesn't like 87 but he isn't using the stock ecu. There is no point in running a higher octane just to get a couple of horsepower difference on a dyno. Many people do this just to "cheat" the numbers. He's not running higher octane on the street and shouldn't dyno tune with it either.

 

Chris said that the numbers were corrected, but I'm not sure that can account for everything, maybe 2-3whp.

I have been reviewing my dyno chart which I will scan tomorrow, and comparing it to Scotts chart from Swoopes car.

I think my cars afr in the 6000-7500 range were too lean now, getting into the high 13's. I got close to 13.2 and held that from 8000 on. My midrange gains were not as strong, which lead me to think that the afrs were to lean. we tried to get close to 13.1-13.2, but we ran out of time and there is only so much tuning you can do at once due to heat soak.

I also am still running the stock exhaust, would could account for another 2-3whp.

 

Another thing about brands of gas, they all go through the same pipeline. Exxon might put in a thousand gallons in Houston and then pull out a thousand gallons in Chicago, but the thousand gallons in Chicago will not be the same gallons they put in, in fact they may have been processed by another refinery alltogether. The only (slight) difference is in the additives package added after the pipeline, which is something like...1 quart per tanker truck.

 

So you paid a couple grand for 5.7hp?

And why such a low number? With intake, high flow cat, and standalone ECU with good tune you should be close to 200, if not at 200.

 

A dyno is a crude device that only shows peak horsepower. It is ONLY a tuning tool and nothing that should be used to judege overall performance of a car. It does not show the other 99.9% of your driving maps and powerband at every other load level. The Interceptor most certainly has a large noticable effect on drivability as well as fuel economy.

A dyno gives us a 2 dimensional readout of a 3 dimensional problem. Can't realy do it all that well.

 

That may be true, but it's just still surprising at how low the numbers are. There are people that do those numbers stock, and yes SAE corrected. With standalone he should really be able to improve on Mazda's tune.

 

And then you have examples like mine that make 205 w/out the header and no piggyback boxes.No idle issues and 17mpg in town/23.5 hwy. We have always used the dyno (engine or chassis) as a tool to tune (engine dyno) or determine gains or losses from bolt on parts. They are both great tuning tools and are not in any way "crude". How do you think that the factory comes up with base fuel and ignition tables? Mazda has a multitude of dyno cells where engines are run under all type of conditions and with fuels from all over the world for exactly this purpose. A loadable dyno is absolutely capable of tuning "driving" maps. Maybe you ought to enroll yourself in EFI 101 there RG, you might learn more than you think you already know. I plan on doing exactly that when they get back to the south again. Even the basics are a great base when coupled with experience. 101 can take you much further than the basics but it is a pre-requisite.

L8r

 

before you totally pan the ECU, I have gone back and reviewed al the data and changes we made and I think I was running to lean in some important spots, therefore I was likely down on power partly due to that. This is more my mistake and inexperience, granted, I had Chris's help but still there was alot going on and I was trying to tune many aspects of the car. The fuel mileage improvements are unknown that this time, but hopefully will be meaningful.

 

I understand. I spent the better part of a summer getting my 7 nailed down but it was worth it and it's still kicking *** in another car. I did small segments at a time, analyzed data and re adjusted till I got where I wanted to be. Good luck with your progress.

 

Dyno Posted

 

at last - someone posts a dyno of the int x - all hail Brillo

 

I wish we could hail my tuning talents, sorry its not more impressive, but hey I'm learning.

 

can you see what causes that lean spike & corresponding drop in power at 7500rpm ?

 

That would be the Aux port opening. If you look at my afr's around 6000 or so, you see its prolly too lean up to the about 7500 where that port opens, which is the real meat of our power band.

Hopefully Scott can comment on the dyno, I plan to richen it up a little in the 6000 area, but I'll have to play with it some, its not quite as simple as just one fuel adjustment change.

 

what is the aux port ? The std AFR chart shows no spike at that point !

any changes to spark advance from stock ?

Whether it is a great tune or not - it is the first chart i've seen since Swoope's which was a frustratingly long time ago .

 

Trust me I know how a dyno works and many different ways to use them when it comes to tuning. However I won't give many shops out there any more credit with a dyno than being able to just do a full throttle run to help brainwash the mass of mindless lemmings of consumers on the market who believe full power tells the whole story. People like on a certain sister forum. You tell me to enroll in efi 101 but I think 99.99999999999999999999999999999999999999999999999 99999999% of all tuners out there should do that instead of me as most of them are bumbling idiots with a computer. In no way am I talking about RB or seveal others that I know. I know which ones I trust and who I don't. There are 4 or 5 people in the world that know how to use them to their full capabilities.

 

dynos look about the same as scotts graphs.. need to do something at the 7500 port opening.... the miderange power above the stock is strong...

btw.. i forgot to mention that most of the dynos on my car were done in nov and dec... mid 70s..

beers

 

argh... i was gonna get a dyno tune but my car is STILL at the dealer... i just called and they say they're finishing up and hopefully be ready by tomorrow...

i always put 93 octane in my car, so it'd be interesting to see what numbers i get. i live in nj and it's been hot as ***** up here as well with ridiculous humidity.

i was really hoping to break 200whp but i guess that might be a little tough... anyways thanx for posting the dyno. good luck with ur tuning experience =D

 

I agree with you and I think that you are saying that you would not learn something from getting some formal training from those who have gone further before you. Maybe I am reading you wrong, you seem like a smart young man and I would think that you would realize how much more there is to learn even about things you already know about.

CS

 

I am glad to see you are getting comfortable with the Interceptor-x. You definitely made an improvement but I am pretty confident there are a few more still on the table. I think overall the run was abit lean. The 7500rpm is actually where I set the VDIE to open when the unit was shipped (although it is user definable with the INT-X). The motor obviously didn't care for that lean spike at all, so definitely add some there. BTW-Tuning tip! When you are adding or removing fuel, especially in an N/A application, don’t just think about the volume. Instead think of how the fuel is actually entering the intake ports. If all the fuel is entering the engine from the intermediate housing and the majority of the air is entering from the front and read side housings/ports the atomization will not be as efficient. Think about it for a few minutes. Did you by chance do any data logging, I am curious to see what the pressure fluctuations looked like at the MAP sensor. Hope this helps, Scott