More results from my 3500Z!

[blackbombshell95]

What octane fuel are you running? Stock fuel pump right?

[ForcedFirebird]

Yes fast burn style heads require less. The aluminum heads with the heart chambers have less timing than the old iron heads.

Good to know .


Dave that cam is sick! It must idle like a 4x4 driving on railrod ties, no? I'm thinking of using a modified 260 advertised duration modified a little for boost.

[IsaacHayes]

Yes fast burn style heads require less. The aluminum heads with the heart chambers have less timing than the old iron heads.

[3400-95-Modified]

I was unaware that the efficency of the combustion chamber will affect timing as well.

[sharkey]

im running 38 degrees, i have had it as high as 42 without knock on premium. old open chamber heads love lots of timing.

on the flip side of things, my buddys ecotec only runs 22 degrees max, and i knock it down to 15 at 5psi. they have an extremly efficient combustion chamber, so lots of timing isnt needed.

[3400-95-Modified]

I guess that makes sense... The race car is 230 234 @.050 and we run 39* yeah its a dist setup and V8 but timing is timing really.

Where I'm at 209.4/213.1 duration

[Superdave]

Long duration cams love higher spark advance... i was running around 38 on my T/A at WOT as well and it's a 270 advertised .510 lift cam with crappy heads.

[3400-95-Modified]

Yes too much gear will hurt your times. Remember your time is really made before the 1/8 marker... Anything after that it just takes way too much power to make a difference.

Spark advance of 36 sounds nuts!!! I'm hitting 24 at WOT right now and I hear about boosted 3800's being in the low teens for timing... I wonder why you can get away with that high of a number.

[Superdave]

Thats one weird dyno graph... I dont know if I would trust those numbers.

Is there something you know of that would be causing those peeks and valleys? because thats nuts... Its like a instant gain of 50hp right before you hit your peak... That would feel like a nitrous hit.

Can't argue the slip though... I musterd a 13.818 at 100mph, so with you hitting 103 I'm sure you'll be mid 13's when you get a better day.

we ran into some strange stuff..


The engine likes high 11 to low 12.x AFR's.. the leaner we took it the less power it made. Dropping the spark advance from 36 to 34 lost me about 2 HP in the top end as well.

I got 0 knock counts during the session! (and yes the sensor works, LOL)



thanks for all the comments guys!


As for the track times, i hope to drop those down ALOT here in the next few weeks. I'll be pulling out my W41 tranny and swapping the good 4th over to the stock V6 tranny with my LSD.. the 3.94 diff is a little too much and i think it's hurting my times..

[geldartb]

Nice build dave. makes me want to put my stuff in and also makes me want to get different heads.

[3400-95-Modified]

Thats one weird dyno graph... I dont know if I would trust those numbers.

Is there something you know of that would be causing those peeks and valleys? because thats nuts... Its like a instant gain of 50hp right before you hit your peak... That would feel like a nitrous hit.

Can't argue the slip though... I musterd a 13.818 at 100mph, so with you hitting 103 I'm sure you'll be mid 13's when you get a better day.

[Superdave]

more later...

[PCGUY112887]

Are you nuts... 232 and 238 duration vs your 206... thats a HUGE Difference.

the lift is close but damn that duration is whats getting him the power. Plus all his race porting setup... HUGE ports FTW!

Hence the in my post

Sometimes it can be hard to get sarcasm across online.

[3400-95-Modified]

His cam isn't THAT different than mine

But his CR does beat mine, kinda wish I put something other than stock headgaskets on now.

Are you nuts... 232 and 238 duration vs your 206... thats a HUGE Difference.

the lift is close but damn that duration is whats getting him the power. Plus all his race porting setup... HUGE ports FTW!

[Superdave]

Soon.. had some after-bash drama today.. I'll scan everything in and find the videos tomorrow sometime. I've had about 8 hrs sleep in the last 4 days so i'm dead for now.. lol