Ok........ Let's try posting dyno sheets again.
370Z new cats - Y-pipe picture by dennylmclain - Photobucket
If someone can host the dyno sheet, I'm gladly e-mail them a copy to post.
Anyway, fresh from the dyno and frankly I'm confused like a big dog.
Drove to the dyno shop, the car sat for 20-25 minutes and it only gained 5 hp and lost torque over best run of the first session. Not real impressive by any means. Whoopie do, that's what I get for $1,100.00?? Let it sit five minutes and another pull. Identical to the prior. The kicker that had me confused is the fuel/air was much better almost a full point higher. ??
OK, so if that's all it gonna make, pulled the high flow filters and it sat a good 25 minutes. Made another pull and I'll be damned, picked up 13 hp instead of 5 (294.6 rwhp)!! What is up wid dat? Maybe the filters are an issue now that it breaths better from the exhaust?? OK the filters back in waiting about 10-15 minutes and it made 292 rwhp.
The bottom line we feel the car is very sensitive to heat soak and w/o a water temp gauge, pretty damn hard to get consistent numbers to compare. The conjecture as to why the first two pulls were lower was the car sat with the hood closed and may have heat soaked the intake manifold. Letting it sit with the hood open more than likely had a fairly significant cooling effect on the top end. Basically did the same damn thing last time with the first run just opening the hood being the worst.
So.......there ya go. Basically a 13 hp gain and a slight gain in torque from high flow cats and Y-pipe, but that could be a tiny bit more. OH...high flow filters also. (a waste of money)
We looked a little closer at the intake and the general feeling was the car could benefit some from a straight path shot of air. Asked what car they see the most gains out a cold air intake and it was the LS1 F-Body. They said they typically see a 7-12 increase in hp on those cars. Said if they got 10 hp, they had a good day.
This particular shop is owned by what amounts to my old full time mechanic when I was sponsored by another shop. Pretty salty and the shop produces some pretty fast race cars.His feeling being the car is so sensitive to heat, was to try two lower heat ranges of spark plug and see if that would make it more consistent. Worth a try.
Still feel with the range of numbers just from the amount of heat you see in the engine, the numbers can be fudged quite a bit of someone were to desire so. Especially if the intake was iced. The car varied by 9 hp from the first run to the better ones on each dyno session. Hey......it gained 9 hp!!
Frankly a bit, but not completely discouraged. Will try colder plugs and tuning to see what happens. Unless there is some magic in the variable valve timing tuning, not sure if people are going to see the gains they maybe had hoped for. Like me for example.
Dunno..we'll play some more and see.