Hello Shiv-

 

Lets try that again,
I noticed both evo's made very similar power curves (91 oct)despite 1 running the perrin fmic w/stock cat vs the vishnu package.

Why? Increased back pressure due to higher cfm forced through the stock cat offsetting the fmic gains or just run to run, day to day variences. were boost levels the same?

 

Well I even offered to bring Brett down and put him up but seems he has better things to do- Something about a glamour shoot with a mag. Well I guess Ill have to wait as I cant afford to put the big man in a 5 star with an open room service tab. Like fear and loathing he will run the tab at $30/hour for 72 consecutive hours

 

Whose to say theres much in the way of dynamic GAINS from a FMIC? Consistancy maybe but if the compressor effeciency and the dissapative effects of the stock FMIC are good enough to reach equalibrium during the pull then a new FMIC would do very little on a dyno

 

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Track Day Track Day...come on lets do it! Shiv can bring out the Stage 2 (or by then 3!) car. That's all the guys do in Europe, we can visit different tracks so we can take turns doing the all- nighters.

That way we can all start *****ing about our brakes

 

After all the pressure drop reductions being claimed by fmic makers, i was hoping to see about a 5 hp gain. I have seen in the past that a 2" Hg reduction was worth about 2.5 hp on our dynos. Now a 2 pound reduction = 4" Hg = ~5 hp. That is based only on a supposed pressure drop reduction. I was also hoping to see some temp reduction from the new fmic as well, on a 28c day I was seeing 41c @ the plenum, stock fmic. Not knowing the plenum temp reduction of the new fmic, if you were to lower a 41c plenum temp down to ~25c, you should then see another 4 or 5 hp at best, based on the cfm requirement to make 300 hp.

None of which was seen. So where are the 10 extra ponies?Hence my question's, car or ambient variances & boost level differences.

One could also interpet from just hose 2 graphs that a hi flow cat gets you as much power as a aftermarket fmic from perrin if run a stock cat. So ~85 bucks for a car sound cat or +700 bones for a FMIC. Which goes against a majority of fmic makers that claim +20 hp.

Then again, people dont race dyno's, they race on a track where the gains may be better realized from a fmic.

Still, I am just curious & thats why I asked.

 

Great post. The psi drop is usually an indication across the core (the volume of the core and its restriction if you will) This shouldnt be confused as a comparison about the PSI drop of the stocker (which I havent seen any confirmed tests- We played this bigger is better game with the WRX until shiv got fed up and tested it and built a proper TMIC) So the dissapative gains from big FMIC might be nullified because of 1) the overspinning and heating of the charge air by the stock turbo (Having to work harder to fill the bigger core) 2) the blocking of rows of fins by body panels and a mixing of the properly intercooled charge with uncooled charge from the blocked fins) 3) the blocking of the radiator and higher engine temps leading to less agressive timing despite the cooler charge

 

 

In the case of the EVO, we've measured an improvement of just 10-12 deg F as far as charge temps go in a Stage 1 application. This is comparing a 3rd party IC with the factory IC. Same day, same testing methods, same dyno, etc,. As for pressure loss differential between the two ICs, it's less than 1psi, making it hard to quantify. That, along with the incremental colling improvement makes the IC upgrade (in that application, at least) a hard thing to argue for. About the only significant thing I would quantify was a few hundred RPM increase in boost theshold (more lag due to having to pressurize the bigger core volume). Of course, the upgraded IC we tested wasn't designed very well, IMHO. Core was oversized for the output the car as making. Plus, the end tanks were way too small which resulted in what I can only imagine as miserable airflow distribution to the entire core cross-section.

FWIW, the IC I'm running on our 11 second car (doh, I'm talking in drag racer speak now!) is the same core dimensions as stock, just a different core design better suited for the big CFMs we are moving through the system. Works better, I imagine but doesn't offer the Bling Bling factor that many want

Cheers
Shiv

 

Thanks for the insight.

 

Shiv,

Can those numbers be attained with the same mods but with just a reflash as opposed to a reflash w/ xede?

 

I'm fairly sure that's going to be a NO. You won't have good boost control.

 

We're getting awfully close. The XFlash on a stock EVO makes provides identical performance as the XEDE on a stock EVO. It's only until we get into the higher boosting Stage 1+ or Stage 2 levels where we still have to do some work with XFlash boost table mapping. Just not enough data points to make a baseline map at this time. Soon though...

Shiv

 

I honestly hate to do this, but I don't know any other way to ask.

DynoFlash recommend the uses of a MBC. I assumed that it was because that they/he only had control of "boost taper". Do you have good boost control within the stock ECU? Can you "map" the boost or just delay the taper?

Sorry for bringing up the competition. Feel free to edit or delete the post if you feel like it.

 

No its amazing what a dedicaited EFI tuner can find in the code. Its there it just didnt come with the flash machine instructions Either way if you mess with the boost your in Street Mod Autoxr