New Dyno #'s

[Tennpenn83]

Engine mods are
GMPP Stage II
2.8" pulley
K&N Typhoon Cold Air Intake
LS4 Throttle body
Dual-pass Intercooler Endplate with Option B
ZZP Mid-length Header/3" downpipe with 2.5" Magnaflow Hi-flo cat
Stock cat-back with Magnaflow Hi-flo muffler
Wicked tuned (by WickedSS2005) to 11.6 AFR using an AEM UEGO Wideband

Before anyone starts flaming about a 2.8" pulley on the Stage II 42.5lb/hr injectors, during tuning, my IDC's never went above 95% and the pulse width stayed at or below 17.

Dyno pulls were done in 3rd gear at 94-95 degrees F and 33% humidity.


http://i20.photobucket.com/albums/b224/azn_ladie82/8-5-08dyno3pulls.jpg

Whatcha think??

I think I definitely need a heat exchanger and meth...

[bc3tech]

what were your IAT temps? that'd be a good indicator. or how much timing you were running

[GMRedline]

I like it! You have to love the nice TQ and HP curve of the LSJ. :rofl:

I wish I would have gotten my Stage 2 setup dyno'd before I installed the 60#s.


Before anyone starts flaming about a 2.8" pulley on the Stage II 42.5lb/hr injectors, during tuning, my IDC's never went above 95% and the pulse width stayed at or below 17.


Most people don't realize that it is "safer" to run a 2.8" pulley with 42.5# injectors on a custom tune. Like you mentioned your car is tuned for a 11.6 commanded a/f ratio. So your tune is demanding less fuel then the GM Stage 2 tune. Even though 95% IDCs is high it would be higher with a GM Stage 2 tune which commands a mid to high 10s a/f ratio. 10.7-10.8 IIRC.

If that was a GM Stage 2 tune your IDCs would be over 100%.

I am going to get my car dyno'd very soon. I have been waiting for things to cool down but I am getting impatient.

[Tennpenn83]

what were your IAT temps? that'd be a good indicator. or how much timing you were running

well the 3 pulls were done all within about 5 minutes so there was no cooldown time.

but this morning when we were tuning, we probably did about 15-20 back to back to back wot runs and towards the end the iat2's started to get hella high, around 210+. evident of my immediate need for a heat exchanger and meth. i don't know exactly what they were at the dyno, but i am going to guess at least 180 or more, seeing as the only cooling mod is the dual pass

timing is set to 20* and the whole time we tuned this morning, i didn't see any knock retard at all until the iat2's got above 200

I like it! You have to love the nice TQ and HP curve of the LSJ. :rofl:

I wish I would have gotten my Stage 2 setup dyno'd before I installed the 60#s.



Most people don't realize that it is "safer" to run a 2.8" pulley with 42.5# injectors on a custom tune. Like you mentioned your car is tuned for a 11.6 commanded a/f ratio. So your tune is demanding less fuel then the GM Stage 2 tune. Even though 95% IDCs is high it would be higher with a GM Stage 2 tune which commands a mid to high 10s a/f ratio. 10.7-10.8 IIRC.

If that was a GM Stage 2 tune your IDCs would be over 100%.

I am going to get my car dyno'd very soon. I have been waiting for things to cool down but I am getting impatient.

thank you for the input. most people think that the 42.5's are inadequate for anything other than stage 2, but your post hit it dead on. if i were to go any lower than a 2.8 then i would most definitely need 60's

[MGM1979]

While the custom tune is safer than the stock tune, IDC in the 90s - even if for a short time - is not safe, period.

There's a reason tuners prefer not to even spike their IDCs in the 80% range...you want that "lee-way" of 20% or so for the what-ifs - and when you're punishing the cars like we do, those times might come a little more frequently than if we were driving around town getting groceries. Any number of factors could lean a cylinder or two out, which is where the computer would step in and add that "lee-way" of fuel into the mix...if it's not there, then boom - that simple.

If you're planning on adding injection into the mix, you'll probably be ok...my original plans called for the 42s and meth, but as soon as I were to drop down to the 2.6 or lower I would have put the 60s back in anyway - so, I'm sticking with the 60s.

You might also consider the return-line conversion - that'll get you a little extra "lee way" out of those 42s as well.


Not all bad though, at all...keep up the good work, and be smart.

[Tennpenn83]

While the custom tune is safer than the stock tune, IDC in the 90s - even if for a short time - is not safe, period.

There's a reason tuners prefer not to even spike their IDCs in the 80% range...you want that "lee-way" of 20% or so for the what-ifs - and when you're punishing the cars like we do, those times might come a little more frequently than if we were driving around town getting groceries. Any number of factors could lean a cylinder or two out, which is where the computer would step in and add that "lee-way" of fuel into the mix...if it's not there, then boom - that simple.

If you're planning on adding injection into the mix, you'll probably be ok...my original plans called for the 42s and meth, but as soon as I were to drop down to the 2.6 or lower I would have put the 60s back in anyway - so, I'm sticking with the 60s.

You might also consider the return-line conversion - that'll get you a little extra "lee way" out of those 42s as well.


Not all bad though, at all...keep up the good work, and be smart.

you also hit it right on the head. i'm considering the return style system, but am still doing research as to how involved it is. the lee-way is not as much with the 42.5's but it will do for the time being. most of the time my IDC's were in the mid to hi 80's and only got into the 90's towards the top of the rpm range (albeit probably right where they shouldn't be that high)

meth should be on in the next month or so, and 60's will be on soon as well. i'm gonna need them for my harrop anyway... lol but until then, they should be fine. then when i install the additional heat exchanger, the meth and the rest of the exhaust, the car will run better and probably not have to worry as much about those 95% IDC's

[GMRedline]

but this morning when we were tuning, we probably did about 15-20 back to back to back wot runs and towards the end the iat2's started to get hella high, around 210+. evident of my immediate need for a heat exchanger and meth. i don't know exactly what they were at the dyno, but i am going to guess at least 180 or more, seeing as the only cooling mod is the dual pass


210? Dam!

Meth Kit and FMIC FTW!

Did you port the inlet of the SC for that TB?

Have you considered slightly porting the outlet of the SC?

[Tennpenn83]

210? Dam!

Meth Kit and FMIC FTW!

Did you port the inlet of the SC for that TB?

Have you considered slightly porting the outlet of the SC?



210+ yes, but after about 15-20 WOT runs lol

i used an aluminum spacer plate that has 2 taps, one on top and one on the side (for when i eventually do get meth and nitrous)

I only used a dremel to grind down the spacer plate, which is about 3/4" thick. it needed to be ground down in order for the TB blade to open.

a port/polish of the s/c is down the road, don't worry lol

[Doc]

interesting....not bad
how's the idle with the ls4 tb..??
I have one, just haven't gotten off my ass to install it.

[GMRedline]

interesting....not bad
how's the idle with the ls4 tb..??
I have one, just haven't gotten off my ass to install it.

The idle is the same as any car with 60# injectors.

Get off your *ss and get to work!

If you plan on porting the SC inlet you will need at least 2 cutter wheels, 2 sanding wheels and 3-4 purple polishing balls.

[Tennpenn83]

interesting....not bad
how's the idle with the ls4 tb..??
I have one, just haven't gotten off my ass to install it.



as long as you change the idle scaling value (?) or whatever it's called, in hptuners, you won't notice any difference at all at idle. you MUST tune for the ls4 throttle body

you WILL however notice a HUGE difference in throttle response. the damn thing is so touchy it probably looked like i was just learning how to drive a stick. much much better down low torque tho as the tb doesn't have to open as far to let in the same amount of air as the stock tb

The idle is the same as any car with 60# injectors.

Get off your *ss and get to work!

If you plan on porting the SC inlet you will need at least 2 cutter wheels, 2 sanding wheels and 3-4 purple polishing balls.

i don't know if i'm brave enough to port/polish my own supercharger yet...

[GMRedline]

i don't know if i'm brave enough to port/polish my own supercharger yet...


LOL! I paid someone to do mine! :)

[Doc]

The idle is the same as any car with 60# injectors.

Get off your *ss and get to work!

If you plan on porting the SC inlet you will need at least 2 cutter wheels, 2 sanding wheels and 3-4 purple polishing balls.

I have a spacer I'll have to modify to accept the larger TB.
It would be nice if it wasn't 100+ outside when I get home....

[aikidoshadow]

I have a spacer I'll have to modify to accept the larger TB.
It would be nice if it wasn't 100+ outside when I get home....

+1 million on that ugh

[Tennpenn83]

I have a spacer I'll have to modify to accept the larger TB.
It would be nice if it wasn't 100+ outside when I get home....

i used a 3/4" aluminum tapped spacer that already has the tapped holes for meth and nitrous. i ground that down so i didn't even have to take the s/c off

i may take a pic in the morning if i'm not too lazy

[GMRedline]

Was this a dyno tune or street tune?

[Tennpenn83]

Was this a dyno tune or street tune?

street tune

[GMRedline]

street tune

Ahhh.

I got dyno'd yesturday and it was NOT pretty. I wish my graphs looked like yours do....

[Cat Ion]

Engine mods are
GMPP Stage II
2.8" pulley
K&N Typhoon Cold Air Intake
LS4 Throttle body
Dual-pass Intercooler Endplate with Option B
ZZP Mid-length Header/3" downpipe with 2.5" Magnaflow Hi-flo cat
Stock cat-back with Magnaflow Hi-flo muffler
Wicked tuned (by WickedSS2005) to 11.6 AFR using an AEM UEGO Wideband

Before anyone starts flaming about a 2.8" pulley on the Stage II 42.5lb/hr injectors, during tuning, my IDC's never went above 95% and the pulse width stayed at or below 17.

Dyno pulls were done in 3rd gear at 94-95 degrees F and 33% humidity.



http://i20.photobucket.com/albums/b224/azn_ladie82/8-5-08dyno3pulls.jpg

Whatcha think??

I think I definitely need a heat exchanger and meth...

Not trying to flame you on this, but I pulled 239/225 3 pulls straight with a fraction of what you have listed. No exhaust upgrades, no meth, mildly custom tune. Also ran similar ambient temps. You might want to look closer at your tune. There might be more in there.

[Tennpenn83]

Not trying to flame you on this, but I pulled 239/225 3 pulls straight with a fraction of what you have listed. No exhaust upgrades, no meth, mildly custom tune. Also ran similar ambient temps. You might want to look closer at your tune. There might be more in there.

i'm only running a zzp midlength header on the 3" downpipe to a 2.5" hi-flow cat to the stock exhaust with magnaflow muffler, so there's not too much gained in the exhaust

what size pulley? i'm on a 2.8" with only the dual-pass so at this point I'm making 17.5-18 psi but it's producing a shitload of heat which, when i get meth and heat exchanger, will really open up some power. ambient was 95 deg, i can only imagine what iat2's were with a 2.8.

i do know that iat's were up around 200 after a few pulls while tuning, and i am still a little rich up top, according to my wideband so i could get a few more i think

Ahhh.

I got dyno'd yesturday and it was NOT pretty. I wish my graphs looked like yours do....

you just need wicked tuned...