i_love_spool

iTrader: (1)

Pick your favourite reason:

Because they're too cheap to to the R&D for an intake when there are far superior products out there already.

Because they don't want to borrow there friends lap top again so they can do the mapping again.

Because they love the look of a stock engine bay, it just oozes JDM power.

Because Vishnu had a fight with Shiva and Shiva stole the plans to the CAI and gave it to the elephant god who turned around and sold it to Vivid.

Hal

Everything?

What about Dwell time, injector dead time compensation and a whole host of other "details".

The XEDE is a PIGGYBACK. Very similar to the EFI Systems PMS.

A "standalone" does FAR more than just fuel, boost, and ignition timing.

As far as who knows more, I'd say the people at Motec, Haltech, AEM, and probably quite a few plain old backyard car nuts.

Hal

ShapeGSX

Yeah, there is absolutely no way a piggyback can compensate for injector dead time. And that is the key to getting good gas milage, a good idle, and a good, calculatable air to fuel ratio with larger injectors.

Ryanmcd2

I know what you are saying. Hell I know Doug at EFI and we did the Rx-7 computers together then sold them to Peter Ferral, boy was Peter a PETER lol, He used to live in atlanta, SUPER smart person. So what do I do for the next 6 months? I guess wait, and that is something I am not good at doing but I guess good things come to those who wait. lol I would do a Motec on this thing but I don't have or want to do that like I did with the Rx.

rarson

Ron

Guys, remember the Xede has timing control. So when boostedwrx says he could only run 18 degrees of timing rather than the stock 21, he is probably saying the knock threshold worsened. So any power gains via reduced restriction that may have been had with the new intake were offset by the amount of timing that could be run safely or consistently.

Hotwire MAFs can be finicky if they see flow disturbances like when an open element filter is slapped on. Some MAFs are more sensitive to it than others. Backflows and turbulence at the MAF's sensing element cause apparent load variations which wreak havoc on accurate/repeatable fuel delivery and timing, which is why OE intakes use flow straighteners and/or long straight inlet sections to the MAF-- to improve the stability of the output.

Hal

From the AMS web site:

"The EVO VIII has a Karman-Vortex type airflow meter and is the same meter that has been used since the EVO IV and is very similar in shape to a 2G turbo DSM MAF "

Hal

shiv@vishnu

iTrader: (20)

Thanks Ron. The car that ran the Ralliart filter had MAF readings substantially lower than the other cars that ran the factory filter. I suspect this is due to MAF misreadings since I have a hard time believing the foam filter is more restrictive than the stock unit. It also induced odd lean spikes as illustrated in the wideband logs which induced knock sensor activity. Theoretically, I may have been able to compensate for those transient lean spikes with the XEDE but there location in the RPM band seemed somewhat random. Of course, due to time limitations, no contolled testing was done to prove (without a shadow of a doubt) that the filter was the cause of this. But considering what we've seen with filters and the normal behavior of the other EVOs present that day, I'm reasonable comfortable in pointing my finger along that direction.

As for my tuning approach behing backwards, I'm afraid, like Ron said, that some folks may not be familiar with the benefits of actual timing control. It is adjusted to eliminate knock correction, maximizing absolute advance in the process. But when the above MAF misreading situation occurs, and knock activity is randomly induced, the tuning process becomes a bit more complicated.

I hope that clears up a few issues with respect to intakes. Also, this thread, like others, has been cleaned up considerably. This housecleaning process will continue if needed. I'm sure most will welcome this.

Have a good weekend guys,
Shiv

gb-motorsports

iTrader: (1)

poor shiv, lol ,,, getting hammered again. hang in there man .

I for one never get into these situations but if you all read Shiv's post after Vivid's reply, you should have stopped and figured it out.


Shiv replied: On my dyno, removing the air intake filter altogether has little or no effect on modified EVOs (running stock turbos).


cheers

gino

rarson

Shiv, I just don't get it, because according to AMS, the EVO has the same Karman-Vortex MAF as the 2g DSM, which doesn't exhibit this.

shiv@vishnu

iTrader: (20)

Get a dyno that logs a/f ratio. Try different intake configurations and see the effects of different designs/filters. Judging by your posts on other threads, it's clear that your only interest is to prove us wrong any chance you can get. Conduct your own testing and see for yourself.

Cheers,
shiv

rarson

Why would I want to look at a/f ratio? The ecu changes fuel maps when it sees over 2.1 gms/rev, which could be possible from an intake. You can't just add a mod and not tune the car. Anyways, I don't need a dyno, I have a datalogger that can display maf output in Hz. Straight from the horse's mouth, so to speak. You're right, my years of tuning 2g DSMs and datalogging my car is nothing compared to your a/f ratio dyno. My post was meant to ask you to delve a bit more into how the stock EVO maf works, as I already know pretty much all I need to know about the 2g DSM maf, and to hear from you whether or not you confirm/deny that the maf is in fact the same on both cars. But you guys don't do DSM's, so I guess you wouldn't know.

I'm not trying to prove you or your performance mods wrong. I'm simply saying that from my perspective, you're coming out of left field and I need you to explain to me a few things before I'm going to buy into your way of doing things. Honestly, I'm skeptical but open-minded. I'm only seeking knowledge, Shiv.

rabinabo

Why does it seem like DSM guys are being overly skeptical about shiv's approach? There's at least one or two other threads like that. If it's his opinion that intakes don't do much for evo's, then that's his opinion. It's not like there's a shortage of intakes around. Hell, you can even buy an intake and a xede and tune it yourself if you'd like.

IMO all the evo intakes that I've seen are insanely overpriced anyways (especially since they're all about $300 for just a very short metal tubes). Personally, I don't think they're worth it because it seems to me that the evo gets enough air with the stock intake.

WildRice

Not all approaches work with all applications. There are two questions I would pose before going with a different intake approach with the Evo. The first question is, how can a tube that is behind the radiators (ic, engine, ac) deliver denser air to the rest of the intake sytem than the stock box that uses a very short flattend horn to intake air from the front of the car where it is near ambient? Secondly, It looks like you would give up any positive pressure generated by the driverside fan and any forward motion of the vehicle as part of the price for more friction (from more surface area with less cross-sectional area) and lag (becasue when the tubo spools the rapid increase in air velocity must act against the air mass in the down pipe).

rarson

Well, seeing as I was able to run 13.7 with the same engine in a heavier car with a much crappier turbo with nothing but an intake, bov, and mbc, I would think the intake was really helping me out. Not only that, but the car definitely felt a lot faster.

My point is, if it's the same maf, I've never experienced anything bad with an intake on my car. I think I'll refrain from any further arguing about this subject because it's clear that I can't get the answer I'm looking for from Shiv.