thesoldier

Okay guys a few months ago I posted my results with my heads & cam package from Advanced induction with the stock modified air box and it came out to 430rwhp & 380rwtq with the cutouts open. I recently purchased an OTRCAI for this same GTO. I wanted to make sure the MAF readings weren't being thrown off since its now mounted in front of the TB. Long story short I loss 35rwhp & my torque stayed the same. Engine wise everything "feels" just like it did when I put down 430 but idk what the heck is going on. I'm lead to believe it's my clutch slipping bad on the dyno but the catch is it didn't lose torque at all which has me scared to take it to the track. I figured even though it's a Different day the numbers on the hp side wouldn't have that much of a gap. I'm by no means a dyno finatic but being that they're used for tuning & I couldn't crack the 400 mark on the dyno has me scared that something is giving in the car & it's only a matter of time. I've checked my driveshaft carrier bearing & that's still good. I'm clueless any thoughts?

thesoldier

Well if anyone was following this I'll update you. I swapped the clutch it for the most part stayed somewhat consistent in the rwhp department at 380rwhp 365rwtq. I did a compression test & all cylinders were dead on 195psi. I did a fuel pressure check and it maintained 58 psi at all rpm. I feel better knowing that the engine isn't hurting but it's disappointing to see all the money I spent barely out perform my Hotcam & 243 heads setup. Next I'm
Going to take it to the track and get a mph on it.

slow trap

iTrader: (22)

if it did 430/380 and is now 380/365 on the same dyno something is wrong.is the dyno graph still look smooth ? afr on the dyno still right ? might try checking your plugs. hard to diagnose over the internet but plugs,wires i would check 1st.

gagliano7

Sound like the new cold air intake is robbing you of power.

jmilz28

iTrader: (13)

Post both graphs...need more data here to help.

thesoldier

As I was doing my compression check the plugs looked fine. They had a look of running slightly lean because my air fuel is 13.2 on the day it did 430. Going back to dyno it was 13.2. All my wires look great from what I can see and they don't show signs of cracking or being burned through.

thesoldier

Here is my dyno graph from the night it did 430 I'm waiting on an email from my tuner for the other graph. I'll try to get an overlay as well.

thesoldier

Yes I already have my stock one ready to bolt back on. Its an odd case but I guess my combo somehow does better with my stock modified airbox

thesoldier

After months of troubleshooting everything with the engine, I did find it odd having some SES light issues for a P0442 Code that would randomly go off and come back on these past two weeks. I did some reading and I was led to the Engine Sensors fuse which was blown. I bet that very well could be the cause of the drop in my dyno numbers. Has anyone ever experienced this before? I wont be able to confirm it until I get to a dyno again but I'm crossing my fingers. Everything else has checked out positive.

kingtal0n

iTrader: (1)

So is this is what happened:

1. car made 430
2. you changed/modified a part
3. car made 380

If so I would go back and reverse #2 whatever you did, and in this light I am sure you see why I would suggest that?

thesoldier

I did that already, car put down the same, I never updated this post, my last hope is that engine sensors fuse that was blown.

kingtal0n

iTrader: (1)

Use the same dyno? Its a Dynojet right? same style roller in the ground both times?

Have a clogged cat or other recent disruption to the air path (new air filter?)
Needs a tune-up, plugs gapped? Do a compression test and check the plugs for signs of problems.

thesoldier

I did a compression test and all cylinders were either 205 or 210 percent. I have begun to break the top end down to see if what everything looks like internally. First my intake manifold had a lot of oil in it compared to the last time. The intake ports got a good bit of oil in them and so do the combustion chambers. The compression test indicates that my rings are in decent shape. Not one cylinder leaked down. this leads me to believe that I was getting excessive crankcase pressure for some reason. I have a remedy for that I'll just run a small filter on the valve cover to let it vent instead of running a hose to the throttle body. I do see signs that my head gaskets were slightly leaking as well. some bolts had a fair amount of oil on the threads as well. Or either that much oil was going through the intake ports. which after what I saw I believe is highly likely too.

gagliano7

Before you go crazy i would go to the track to see if runs the same times. If so it could be the dyno now reads lower than the time you had dynoed last time. If it runs the same and the power feels the same i doubt anything is wrong. If you really lost 50 hp you should be able to tell while driving.

thesoldier

Thanks, I definitely can't tell of a power loss at all and now that the car isn't my DD I will definitely be tracking it a lot.