seZy350

I have a dilemma and see what anyones thoughts what this could be. Recently got my motor redone( built for n/a) mods to list is the bottom end just got reworked with cp pistons 11:1 and eagle rods it was overbored .020 and redecked. I have full bolt ons with long tubes ypipe intake pulleys and exhaust... 3000 miles later with the new bottom end i go to a local shop to get it tuned with utec. With utec hooked up and set at 0 it was at 178whp stock ecu 212whp and final tune it made 238whp....let me also statee this is a 06 revup. Those numbers just dont seem right at all.. Ive seen non revups STOCK making if not more the same numbers im making right now with the bottom built. Tuner said car is running with no hiccups no knock and no codes are thrown... What could it be? Exhaust restriction? Need a spacer for the intake? If that was the case i still wouldnt see it making much different....

MREDDLE

You should post a copy of your dyno with A/F logs on it. Then get a commpression check and a leak down. There are way to many itens that could be wrong and without more information we cannot help. There could be a problem with the tune, dyno, machine work, cam timing, fuel, all of the above or something else?

whitez33350ztt

iTrader: (4)

i made 285 whp on a dynojet with full exhaust and cams, stock bottom end. something isnt right and there are many things that could be cutting ur power down, just like MREDDLE just said, do you have cams?

seZy350

AFR is at 14.20 after final tune and 13.79 before. once i get the charts uploaded to my comp i can post those. whitez - thats what i am saying, something is definitely wrong since mine is a revup it should be making way more then 238 with bottom end work.. =/ i also forget to mention i am running cams as well. this car has just been a nightmare for me =[.. first oil consumption now this..

as for the tune i just cant believe that it could be the tune. brought it to one of the most respected tuners here in AZ.. the weird thing is if you see the difference between the gains there is quite a big gain in numbers.. i just dont see why the total power numbers are so low though.. i need to get the charts uploaded!

Frostydc4

iTrader: (3)

That could be your problem right there. Are you able to get an AFR reading for each bank?

I'm assuming this is a dynojet? What boltons do you have?

12AutoX

iTrader: (7)

A dilemma is when you have to choose between two options that will both suck in some way. What you have, my friend, is a PROBLEM.

That being said, your AFR for an NA build should be between 12.5:1 and 13:1 if you are looking for power. It's really wierd that you have such lousy power before the tune.

MREDDLE

I dont know if this is your problem but, I did some calcs for Dynamic Compression and with the some out the larger cams out there with valve overlap, ect. If you dont really bump up compression and get some air in the motor DYC goes out the door and you will lose power.

Z1 Performance

iTrader: (564)

bottom end work in and of itself does not net any horsepower

type of dyno, calibration, etc etc also play equally huge roles. Lots of holes in the story, no one can say what it is till those holes are filled in

tuko316

iTrader: (6)

Even 11:1 isn't enough?

How big is too big?

MREDDLE

Well, That is a good question and is completely relative. this is very technical but, I am using JWT C8 cams and if I install them at stock timing then at 11:1 my DYC would be 7.01:1, stock DYC is 7.84:1. So this would be a loss of power. I would have to bump static compression to 12.5:1 (DYC 7.97:1) in order to gain power in the stock rev range. Now there are many factors that would change all of this and I don't have that kind of time to go over all of it. I brought up Dynamic Compression only to prove a point that you need to find a good performance shop that can give your motor and setup a once over, you have a problem that just can not be solved over the Internet. I wish you the best of luck.

seZy350

actually dyno used was a dynapack

boltons consist of ypipe,longtubes,exhaust,intake,pulleys,

Z1 - yes i understand that bottom end work alone will not net power, but with the boltons cammed and it being a revup and a tuned utec wouldnt ya think it would push out more then 238...as for calibration not too sure i have to ask the tuner... still trying to get the charts emailed so i can upload and post it for you guys to see.

Z1 Performance

iTrader: (564)

No I would not assume anything the least of which is whether or not you
improved things. The only thing you can assume i you changed things. Change does not ensure positive results though and you could have a multitude of things potentially going on

The amount,or name of parts you have has nothing to do with how much power the car makes

Z1 Performance

iTrader: (564)

But you would not install a cam like a c8 and run stock cam timing so it renders any such calculations essentially useless.

MREDDLE

Z1... As stated above. You are correct. What I wrote is just a starting point to figure out how a cam will react with-in a given motor. It is very hard to calc dynamic compression with adjustable intake cams. Maybe, I shouldn't give my opinion but, without others opinion what is the use of this forum?

MREDDLE

The cam timing on my motor will be degreed for my setup and my requirements.

Z1 Performance

iTrader: (564)

My point is it's not a starting point at all because the dynamic ratio is tied inextricably to the cam timing. Any calculation based on a stock cam timing curve with that cam really tells you nothing. Opinions are great but if they aren't taking all the facts into account they just confuse people.

Fwiw a utec would not be the ecu that would even be on my radar for a revup engine build, let alone one with cams. Who helped you plan this build before you started buying parts? They should probably retire or stick to their day job

MREDDLE

Fair enogh. Thank you.