reduce voltage by 10% rescale maf by 10% .... surely..............



Mine will - but I haven't got the turbo to get there

 

Seems to me it'd be easier to just move up to a larger maf housing. We've had the discussion before. I'm surprised nobody has done it yet.

wrt maxing the maf, it wouldn't make sense for it to go to zero at or above 5V. If anything it should just flatline just like any other similar pcm situation


.

 

Main reason it hasn't been done is that people (on this forum anyway) have not pushed the boundaries this far before . Mainly because of the max calc. load bogey - which we have now resolved

Next issue is the maf and I for one think a voltage drop and maf rescale is a much better/more elegant solution than an oversized maf tube . So long as we have enough headroom that is .

A biggermaf tube will be difficult to calibrate .
Not even sure it will be possible to even get the stock sensor central to the tube
Plus it's a big ungainly pipe which will throw up mounting and transition challenges.

 

Your previous 10% correction comment is incorrect. You haven't thought it through fully. A larger maf with compatible maf sensor. They are out there with both the maf and temp sensor calibration charts supplied.

 

Yeah.... not a straight line so can't do that .

 

Fazda, you are the man! I got back from Seattle and threw in my stock yellows in the P1's Friday night but they turned out bunk. eBay specials, lol! Anyway, Fazda swung by today with a set, we popped them in and she purred smooth as silk I also picked up a used Turbo XS HP boost controller just for some quick testing. Hopefully that shows up tomorrow or Tuesday... I will try to get some logs this week and report back!

 

great news slash. Keep it up man

 

sounds like some good progress . Good luck .

 

just got off the phone with PTP. Ryan was telling me about his personal experiences. he told me that what he felt was him running out of injector was actually him running out of fuel pressure. "The returnless fuel system is crap" Just wanted to say that before I forgot and just in case we see this as a problem once you start playing with the car again.

In other news, the phone call resulted in a great deal on the same "Piping kit" you purchased from ebay. In all Ryan at PTP, now Stout Performance, seems knowledgeable and very nice. The kits he is installing now are using the Cobb and Haltech in conjunction to put down 325hp at 10-11psi. I meant to ask him for a dyno sheet.
Sorry to semi-threadjack...

 

Not a thread-jack at all, this is good info, thank you for sharing! Sorry I haven't updated. Fazda and I got the injectors installed this last weekend. I had to make another trip back to Seattle, but I am back now. I was also waiting for my boost controller to show up, which was in the mail today. Not sure if I will get it in tonight. I need to go back to a lower spring and use the bc to slowly crank up and see if I run out of injector/pump/etc.

 

A dyno sheet would be awesome. Any details on the turbo the are using? Mine is comparable to the turbo that was included with the original PTP kit and 325 @ 10psi would be in the ballpark with what VD is estimating from my logs.

 

I want to say he mentioned the latest turbo was a precision unit. 5862, I think. He said somewhere around 15-16psi is where he started noticing the drop in fuel pressure. He said he was capped to 385whp in that area. We didn't go too far into how he tweaked the MAF. He did however mention that when tuning he could either get the idle great or the midrange great. He couldn't have both. This leads me to believe his methods of maf tuning most likely meant scaling the entire maf by a multiplier.

 

Did he mention the fuel pump he is using?

 

PS: just finished installing the BC. Hopefully will have it dialed in and do some logs tomorrow.

 

Slash is there any chance you know the major and minor on both sides of your turbo?

 

Interesting . I still think slashes' injectors are what was causing the leaning out he was getting the other day . I've seen the exact same thing a couple of times and it all adds up ............IE power level, injector capacity , the afr behavior.

 

Not at the moment, but I can tell you it is a Comp Turbo CT4-6062 with billet compressor and Triplex BB with .70 A/R cold side and .81 A/R hot side.

Comp Turbo - CT4 Series

CT4-6062 433300-0013 Dynamic Aluminum with water ports HE 62 670

 

he did. i can't remember for the life of me which one. it wasn't a walbro or aeromotive unit though. I remember thinking to myself "why is he running that?" Maybe it will come to me later.

 

Got the boost controller in. Tying open the SSV seems to have alleviated the AFR spike around 4K. Injectors seem to be doing the job up top. Need to work on the tune, but wanted to share the logs. 12, 13 & 14PSI, roughly. Brettus, I know you aren't a fan of ZIP files but I am in a hurry, so figured you'd rather see them now then later FYI, I've barely had a chance to look at them, haven't really dug in yet...

 

looking good man .

Are you at slightly less boost though ? Thought you were hitting 15 before ?

 

Yes, I didn't want to risk running lean again if the previously logged high AFRs were due to something other than injectors. I only have a 5lb and 10lb spring so I picked up the Turbo XS HPBC. Now I have the 5lb spring back in and I can adjust the boost slowly and see if I have any fueling issues after going to Y/UY/UY injectors.

 

Good stuff . It does look like the injectors have done the job but you didn't wind it out all the way on that 14psi log so even though loads were about the same as the 15psi log I can't tell for sure .

 

Yeah, I still need to analyze the logs, bouncing from meeting to meeting today...

 

Also, I set my main rev limit to 8250.

 

I was looking for 4inch MAFs and came across a couple. I'll put one of my finds here:
HTP 4.0" Full Intake System + 51R Battery Tray Combo (Mazdaspeed6) - Hi-Tuned Performance Products

HTP makes a 4inch intake for the speed vehicles. The actual ID of the maf tube is 3.83 but that's a decent jump from the stock MAF. This would be a decent upgrade when/if the times comes. Of course scaling the MAF is another issue.
looking through the speed forums There are guys pushing just over 700hp with room to go using this MAF. Doubt the renesis will get there but If we ever start maxing out the current MAF then this seems like an option. It is rather expensive but the linked item comes with extra stuff that we obviously wont need.