couple things needing addressing
 

:hi:

I just had a couple questions/concerns about my evo ix.

First off when I first start it and let warm up is it normal for the afr's to be rich at first (10's) than gradually increase to 14.7/14.3 flux once warmed up?

Than secondly, This problem has exsisted since I bought the car.. Whenever crusing at a steady speed (usually happens at highway speeds) if I give it more throttle to merge or pass etc. than let off to 1/4 or very light throttle it will start jerking and go piss rich. untill I give it gas again.. Ive looked over all lines etc just cant find out why. I went back to a perrin intake (uses stock maf scale) and that didnt fix it. Its just really annoying when Im driving somewhere and everytime I try to let off the gas it starts jerking. I get the "WTF is your car ok" look alot from passengers.

It is tuned by shane, but I plan on getting a retune for e85 sometime this spring since my e85 tune is quite old. (currently on a pump gas tune also done by shane last march)

mods,

perrin intake/perrin foam filter
megan o2 housing
dc test pipe
greddy ti-catback
pte 1000cc's
wally 255
crushed ix bov (did it even when it was un crushed)
nesei licp
ams fmic
ams mbc
Pretty much it.

If anyone is in the mankato area I can show you what im talking about.
Or I will be in shakopee tomorrow afternoon

Re: couple things needing addressing
 

Probably needs a retune I would think.

Re: couple things needing addressing
 

See thats what i thought but this pump gas tune Im on was done in march... Who knows if i can't figure it out hopefully shane can when i take it to get tuned on e85

Re: couple things needing addressing
 

Does the bucking happen in a high gear and low speed? Ex: 5th gear, 50mph

Another thing: When I had mine, I switched from a Injen intake to a Perrin and the car was running a good deal leaner at WOT (12.1 vs 12.6).

Did you change the intake before or after the tune in march?

Re: couple things needing addressing
 

No usually happens when its around 2500 rpm and up will do it in any gear.

Yeah changed intake after tune but MAF scaling was stock already so nothing had to be changed.

Note it did it with both intakes aem and perrin so i don't think its related to the intake. It needs a new filter though, previous owner had the damn foam filter just laying on the acd resavor so it got mighty dirty and ripped on the bottom side from rubbing and being pressed up on it... Tisk tisk

Re: couple things needing addressing
 

That ACD reservoir is a pain in the ass always rubbing on filters

Re: couple things needing addressing
 

With this perrin intake it don't. I was even able to mod the stock air box to fit over the perrin intake and filter ;) looks nice and stock.

Re: couple things needing addressing
 

is your bov vented to atmosphere? if so, that could be your issue. like when you get boost up to 0 and let off a little the bov opens, and stays open cause there is no pressure/vac shutting it. all that metered air is getting dumped, causing pig rich jerking/buckin

Re: couple things needing addressing
 

^good call on the VTA but the perrin intake is setup for recirc.

The part about AFRs during warm-up is 100% normal and expected. AFRs will be rich until the o2 sensor and coolant temps fully warm up. 10's seems excessive, maybe there's a way to tune that, not sure.

The bucking issue you are describing plagued me in my evo8. It is horrible and I fucking hated it. Three things helped me:
-having the BOV away from the UICP (like stock), not directly mounted on it.
-Greddy RS valve -> Evo IX valve
-Speed Density conversion. Some people see no change but go read the posts I made, I fell in love with the car all over again.

Also, basics basics basics. Clean your MAF (carefully!), check for boost leaks, check timing, engine health, etc.

Re: couple things needing addressing
 

Thanks for input guys!

I have the crushed IX valve it is right on the perrin intake with stock tube going to stock uicp.

I am thinking of going to SD i actually want to.

I noticed when i let off to part throttle the afrs go very rich which where it starts gurgling and studdering.

I have done boost leak tests and every time i change oil i look over everything i can and everything seems fine. I hope a SD conversion cures it. Can i use stock bov for SD? I wanna keep the stock look (don't want to replace stock uicp or could i use a small hose and mount something like the tial on it?

As weird as it is sounds like bov because when it studders the bov goes into sneeze mode and goes nuts until i give it gas.

Re: couple things needing addressing
 

I will take a video today for everyone to see.

Re: couple things needing addressing
 

You are right, it is the BOV but it is also the MAF reacting to the interrupted airflow, it resonates and goofs up the MAF. Yes you can use the stock BOV for SD.

Re: couple things needing addressing
 

I tried to get a vid, my phone is way too crappy to record semi descent quality. But yeah after winter I want a SD tune so hopefully that fixes it. Just completing on using my ix bov or getting a aftermarket one.

Re: couple things needing addressing
 

you going to be around tomorrow or any other day this week? I should be around so shoot me a text

Re: couple things needing addressing
 

I work

Re: couple things needing addressing
 

Ya know, the other thing that really may (or may not) have helped my car was that i went form a MBC to a GM BCS (3-port). Just something else to try. You could bypass the MBC and go directly from the boost source to the WGA as a test.

Also, what is your source for boost control vs BOV? IIRC I sourced mine separately directly from the intake manifold (i.e. no 'T'), that may have helped too....with the BOV and MBC fed off of the same small tube you can imagine what happens to localized pressure while this is happening.

Re: couple things needing addressing
 

Yeah I have a T going from intake maifold to bov and mbc.

if I try to do it on their own each, would I just do MBC= WGA leave alone, than for the other side go from j pipe to mbc? than intake main directly to bov?

I will do the test and go wga to turbo and see how it does. I have been looking into a 3 port, ive read many good things on them. I am complating on when getting my tune switching to a 3 port.

SD is a go though.

Re: couple things needing addressing
 

Honestly don't go SD unless you have exhausted all other options. It adds another layer of tuning complication. IMHO make sure you have a way to log your car (including wideband) so you can do quick and easy health checks on it. That being said, it may very well be worth it!

Not sure I follow you on what you said, but as a test route directly a single hose from the boost source (turbo outlet nipple?) to the WGA nipple, that would delete the MBC.

Also run a feed directly from the IM to the BOV.

Re: couple things needing addressing
 

I have a wideband, need to upgrade to a aem so I can log with it on my labtop. Basically have it for safety since I didnt tune the car, although Id like to it just seems too complicated for me.

Even if I have shane do the SD tune you think I would still be a hassle?

Yeah I know what to do on the test route (WGA-TURBO). But as for getting rid of the T and do direct line set up's...

It would go WGA-MBC, MBC-Turbo J pipe ..... Than Intake mani-BOV? Correct?

Re: couple things needing addressing
 

Yip you got it.

The wide and is a safety thing I think any e85 car should have. The mix changes, it's cheap insurance.