ctsv 2.55" pulley and intake on stock injectors

[sgod1100]

Attachment 77943Attachment 77944

Alright, so i did some data logging with the new maf model you sent me and the knock is still there. I tried retarding the IAT spark advance along with the main high octane spark table, but i'm having no luck. My actual timing advance seems extremely low. I also don't understand why my IAT2 isn't displaying correctly in the graph area. It displays correctly in the channel area but not the graph. It will oscillate from the correct value to what looks like to be IAT (prior to supercharger).

This run was done in 4th gear from about 2k rpms to about 5500k rpms

Any recommendations on why i'm getting knock in regards to so little spark advance???? thanks

nevermind on the IAT2 thing...i didnt realize that i need to NOT pick the "generic sensor" option...so my IAT2 are displaying correctly

[gmonde]

in my application I had to change the knock sensor setting ,the factory setting is set to sensitive ,, it was picking up hard shifts ,hard launches with tire spin that created wheel hop ,I made a small change and it was enough to get the static out

[sgod1100]

I'm pretty hesitant to do that though...this pull, along with multiple other ones, was done in one gear and since it was 4th i wasn't spinning either

[GHuggins]

Set your pump duty cycle from 4000 up rpms to 96% and then set your max duty cycle percent to 98%... Your still lean and pretty much out of injector... If you put long tubes on with gutted cats it would be better and could use stock injectors, but honestly injectors themselves are cheaper - on the other hand you would be better off with the better flowing exhaust - all up to you... The pump settings "might" just get things back better in line...

[sgod1100]

I actually have ID850s on my dining room table right now..Lol. I haven't put them in because I wanted to get more familiar with hp tuners and data logging. You wouldn't happen to have a tune for a 2.55 (or 2.38) pulley with ID 850s would ya?? I'm surprised i would be out of injector at such a low rpm...

[sgod1100]

How do a lot of these guys get away with stock injectors on a 2.55 and I'm over here running out of fuel at 4k rpm...lol...just my luck

[GHuggins]

Your not necessarily out of fuel at 4000rpms - you are pretty much close to being maxed up higher than that - 90+% injector dc... I'm having you ramp in the pump at 4000 just simply because that's typically where boost really starts coming in and more fuel demand with it AND in actuality your not knocking as much as you believe - you knock then it slowly removes the timing back out... You could be more aggressive with a lot of your settings, but as stated previously you really need a dyno for this... Why "other's" are getting away with it - well like I said - they could be running headers = 1 less psi of boost = fuel system able to keep up / they could just be not giving a flip and giving cars back to customers left and right with 100+ injector duty cycles - see that one a lot... Or maybe "your" fuel system just doesn't flow like "their's" for whatever reason... Who can really say... I don't have any 255 pulley tunes that didn't have injectors and/or different extra supporting mods such as headers or cat deletes to lower boost back down some...

[GHuggins]

You also need to make sure that your running good fuel and nothing on the car is causing picked up drivetrain noise to set the knock sensors off... You might even consider having your backpressure checked to make sure your cats aren't melting and causing excessive boost pressures and corresponding knock on top of that... All the little things add up in scenarios like this...

[sgod1100]

You also need to make sure that your running good fuel and nothing on the car is causing picked up drivetrain noise to set the knock sensors off... You might even consider having your backpressure checked to make sure your cats aren't melting and causing excessive boost pressures and corresponding knock on top of that... All the little things add up in scenarios like this...

Yeah , I was thinking that maybe it was false knock, but I didn't want to do any "desensitizing" to the knock sensor for fear of messing the engine up. I was also thinking about taking like 6-7 degrees of timing out of the main spark table just to see if that knock is still actually there...any problems with doing that?

[GHuggins]

No, that will let you know if it's false or not, but keep in mind your tune is setup to ONLY pull 7 to 8 degrees due to knock alone - you still also need to address the fuel issue

[sgod1100]

No, that will let you know if it's false or not, but keep in mind your tune is setup to ONLY pull 7 to 8 degrees due to knock alone - you still also need to address the fuel issue

yeah, I'm thinking about scrapping that idea of retarding the timing...I'm thinking about just biting the bullet and throwing in the ID850s along with the injector data and start doing some light throttle data logging. I'm going back and forth between doing the timing retard thing and just putting the new injectors in.

[gmonde]

Yeah , I was thinking that maybe it was false knock, but I didn't want to do any "desensitizing" to the knock sensor for fear of messing the engine up. I was also thinking about taking like 6-7 degrees of timing out of the main spark table just to see if that knock is still actually there...any problems with doing that?

as mentioned the knock is high and seams to be no reason other than crappy fuel (yeah injector duty is up but I was over 109% and it didn't knock consistent like I see in your log,, I second checking the cats,,

[sgod1100]

I just don't think it's running lean considering these KR areas are 3-4k rpms. I really don't want to test the cats either..lol. If I'm going to spend money I might as well get test pipes

[GHuggins]

O2s aren't exactly a wideband, but they typically don't lie either. Once you tune enough, you'll be able to see how the mv correspond to your air fuel ratio.

[sgod1100]

as mentioned the knock is high and seams to be no reason other than crappy fuel (yeah injector duty is up but I was over 109% and it didn't knock consistent like I see in your log,, I second checking the cats,,

Right now I'm going to looking at any spark advance adders that maybe adding timing that I can't see.

[gmonde]

from you log you posted its not adding timing ,, your commanded is around 11.2 or so and fuel pressure is over 50psi ,,but as mentioned as soon as the mv on the o2 sensors drop on both banks ,the knock retard comes in and the timing drops ,,I would keep adding fuel to the maf table ,, start at 8,500hz and up 5% at a time ,,, you also mentioned to had the id850 injectors ,,, I would throw those in NOW!

[DrkPhx]

^^^ I agree about the injectors. You spent good money on them, so install them, load the data and datalog. They're relatively easy to tune and you need them. You really need a WB hooked up to confirm what the actual AFR is. You also should change the spark airmass so it extends beyond the default 1.36. You're at 1.51 g at 4200 rpm, so it will only increase above that. Also change change the commanded PE AFR/Lambda to a flat number until you get it sorted out; otherwise you're chasing a moving target. It's also adding timing at WOT from the AFR Correction table based on rpm and EQ ratio. It's adding 2-3 degrees from that table alone. It looks like the IAT table is also adding some spark as well. If you have headers, I would check to see of they're hitting the steering column which is not unusual on a V. I would also check to see if the exhaust is hitting somewhere. These motors are hyper sensitive to any type of knock and can cause issues.

[sgod1100]

^^^ I agree about the injectors. You spent good money on them, so install them, load the data and datalog. They're relatively easy to tune and you need them. You really need a WB hooked up to confirm what the actual AFR is. You also should change the spark airmass so it extends beyond the default 1.36. You're at 1.51 g at 4200 rpm, so it will only increase above that. Also change change the commanded PE AFR/Lambda to a flat number until you get it sorted out; otherwise you're chasing a moving target. It's also adding timing at WOT from the AFR Correction table based on rpm and EQ ratio. It's adding 2-3 degrees from that table alone. It looks like the IAT table is also adding some spark as well. If you have headers, I would check to see of they're hitting the steering column which is not unusual on a V. I would also check to see if the exhaust is hitting somewhere. These motors are hyper sensitive to any type of knock and can cause issues.

Since i last posted on here, i zeroed out those spark adder tables and was able to get a pull with virtually no KR (a few 0.X blips but nothing major). My latest run is below. I know i still need to put those injectors in and will do so in the near future. i'm lame and just have the stock exhaust manifolds as of now. I appreciate all of the suggestions though!

wot with timing changes and NO KNOCK 3_31_2018.hpl