GoatCaptain

iTrader: (2)

Ok i've got a 402 stroker thats only been in the car for 9 months and has about 9k miles on it. I need thoughts on why i'd be down on power between dynos, below is the leak down results also.

So recently i purchased alot of stuff for the car and was all set to have it installed (ported LS3 heads/intake, 4 inch intake/100mm maf). So when i went up to get my intake and get the heads swapped the shop did a baseline dyno prior to install. This is where the red flag went up, the results on the dyno were 400/408 which after the motor was put in it produced 475/447 so something isnt right. With that said they're different shops and dynos so i expected a difference but not that much. So the shop did a compression and leakdown check for me to see what was up, the results were,



So i decided to hold off on the install until i could get my car back LMR since they installed it and its under warranty with them. After i called them and told them what was up they immediately set up a time for me to come in. They've been great to me so i'm sure they'll get this diagnosed and if something isnt right they'll get it fixed. Hopefully its nothing major, we'll see.

They said that some blow by is expected since i have nitrous pistons but they want to do their own dyno and leakdown test this week to see for themselves. My car doesnt smoke normally or burn any extra oil than these ls motors normally do. The gas mileage hasnt really changed nor have i felt any massive loss in power in my butt dyno. However the car obviously is putting out too much smoke on the dyno at WOT which isnt the norm for my car.

Recently i had the car up at the shop because of stuttering and some sluggishness which ended up being a dirty maf but since cleaning it i havent had any noticeable problems. But seeing that big of a difference in dynos and the leakdown results have me concerned. Since its my first time with a leak down test i figured i'd see what you guys thought of the initial results.

Here's the dyno video,



thanks for your thoughts

GoatCaptain

iTrader: (2)

bueller?

DarknessHunter

iTrader: (10)

could be a million different things

LS1x2

iTrader: (11)

I don't see any blue in that smoke to make me think it is oil. It is more likely fuel which means it is VERY rich. Normally you can still make good tq running rich with low hp. It's a guess, but I'm thinking 1 cylinder isn't firing. Could be anything though.

GoatCaptain

iTrader: (2)

Plugs look ok

Number 6



Number 8



Number 3

5w20

iTrader: (21)

looks like each cylinder is running considerably different than the other.

GoatCaptain

iTrader: (2)

doing a head swap and inspection on tuesday at LMR to get a better idea of whats going on. Swapping head gaskets, heads, intake, cai and retune so that should eliminate all possibilities. If the leakdown test is still off and power isnt back then its likely the rings. we'll see

GoatCaptain

iTrader: (2)

well its at LMR now and they're working their magic on it right now, should be done this afternoon with the head/intake/retune swap. That will eliminate every other possibility other than the rings. we'll see.