making same PSI after P&P, cams, headers. Why?

[Bullseye96]

I'm wondering why my car did not lose boost after I rebuilt the engine with a 9.5:1 vs. 9.8:1 compression, stg3 P&P, cams, and headers. can someone fill me in as to why the PSI stayed the same rather than dropping like I was expecting? I'm using an autometer boost gauge btw.

 

[flowgoode]

I read through your build thread on that other site. You said you were running a 10# pulley but only seeing 9# because of restrictions...well maybe now your only seeing 9# because of the extra flow? Just a thought I had.

Nice build btw...car looks good!

How do you like the BBK LT's? and the Accufab TB? I think longtubes will be next for me.

 

[Bullseye96]

I read through your build thread on that other site. You said you were running a 10# pulley but only seeing 9# because of restrictions...well maybe now your only seeing 9# because of the extra flow? Just a thought I had.

Nice build btw...car looks good!

How do you like the BBK LT's? and the Accufab TB? I think longtubes will be next for me.

well it was actually just opposite. pullied for 9# but I had started to see 10# a week or so after the car was tuned with the 9# pulley installed. I still see between 9-10. I'm kinda stumped.

Thanks for the compliments :rolling: I really like the BBK LTs. I really thought that there would be major clearance issues, but it's not bad like everyone was saying. The throttle body works very well. I was thinking that it might be a little hard to tune drivability with because of the massive diameter, but so far it's been great. I'm happy with the car. :rockon:

 

[timpryor]

so when are we gonna run Waylon?

 

[Bullseye96]

so when are we gonna run Waylon?

shit, I'm still getting tuned. we've been playing with the meth alot, and I'm raising the boost. Plus I'm not too proud to admit I might lose LOL!

 

[swoosh_stang]

The important question is how did the rebuild effect performance?

Also, where is the boost measurement taken from?

 

[Bullseye96]

The important question is how did the rebuild effect performance?

Also, where is the boost measurement taken from?

well the full tune is still in progress since my car was put back in the middle of a full shop after I broke in the motor. Since my previous tune was done using methanol, I must wait until a meth tune is done.

My previous #s were 401whp & 380tq @ 9psi with the small w/m nozzle at about 12.5:1 a/f ( car was stock with Kenne Bell, fuel pump, injectors, maf, Catted X, and Hooker catback.

without the meth on the above mentioned setup, I was only able to make 355whp & 360tq since the IATs were outrageous and car was tuned on a 100* day vs. the 85* temps the methanol was tuned in.

Now with only 500 miles on the motor, NO methanol, 11.8:1 a/f, the car made 38?whp will a beautiful curve. This is with the new setup. Now keep in mind we did relocate the IAT sensor to below the blower to get true IAT readings which were in excess of 220*. It would seem as though I did gain power without the methanol. We will be using the middle size nozzle so as not to make the a/f dependent on the methanol when the final tune is done.

Aside from the peak power gains (which are not really known yet), the engine is completely different in feel. I can actually feel how well the engine is balanced. When I lay into it, the rpms ramp up a hell of alot quicker than before. The rev response is very quick with immediate engine deceleration on free revs. The cams have an almost non existant lope. Blower has more "whistle" when cruising as well. I know that this car is not going to make it's potential with this non I/C KB, but it will be a little while before I can contemplate another FI source. This means that for now I must make the best of my blower.

my Boost measurement is taken from the Open House manifold via the Autometer pillar mounted boost gauge. I know that a better gauge placed much closer to the intake is more ideal, but this was the same setup that I was reading from before the build. my tuner has been reading off of the manifold during the tuning process and told me that he see's 9psi rather than the 10 that I see in the car. still there is no drop in psi. is this odd?