cam shaft swap help

[SappySE107]

The low end power should be close to stock. Past 4k, there is kore power with the new cam and that is probably why it needs tuning there and doesn't feel as powerful right now.

[Rootie524]

i know 60dgrzbelow0 that's where i plan on getting all my ported stuff from..like heads and LIM and UIM and TB. and idk if you have headers yet that will work on the N-body.

heres a pic of the cam spec sheet:

[SappySE107]

Tuning for sure. Can you post the cam specs again? My ported heads will improve power all over because I focus on flow with velocity. The cam is a huge impact on powerband though.

[60dgrzbelow0]

Rootie.... Unless you have already covered this... Why not ask Ben (WOT-Tech) if he has some or all of the performance or modified components you are thinking about adding to your engine? Chances are... he either has them...or knows of a member who does...

[Superdave]

Tuning will fix most of that.

[Rootie524]

oh and i can definitely feel the power band of the new cam. 1k-3k it's pretty slow then you start to feel it growing in power..its quite nice.

only concern is..i lost alittle low end power..no problem..but if i need doing mods..wont that make low end power horrible. like if i power the heads, get headers, get the 3500 vavles, ported 3100 LIM and ported 3500 UIM with 65mm TB..won't that make low end horrible?!

how do i keep low end decent while having awesome high end? i hope you understand what im saying

[Rootie524]

well ill be sure to tell them to do VE and then go for the hp numbers.

[SappySE107]

You can only use the upper intake. I hope they are doing a VE tune first before they go for the hp.

[Rootie524]

i've setting up dyno time this monday at a local dyno that can tune it for me. im excited about that.

and quick side note..i can do a 3500 top end swap (LIM and UIM) on my 3100 right? if i get the ported 3500 intake manifolds how much better is it than ports 3100 manifolds?

[IsaacHayes]

^^^ It could be water vapour. That is a by product of combustion.

If you put in bigger injectors you will have to have it tuned right after, as it will flood the engine if you don't. The computer won't learn, but it might get better as far as driving around like a normal person would. Don't go past 70% or so throttle as it stops reading the O2 sensor there and goes off the programmed tables, but since those aren't tuned that is bad... Drive it gently and normally without getting on it too fast and the PCM will adjust and be more driveable. It won't be right but as long as it's not off too much it shouldn't blow up but it's not good for it to just drive it untuned all the time...

And don't disconnect the battery, if you do then it has to start all over at trying to compensate.

You really need a tune, especially if the cam is a moderate or aggressive one. Drive it gently until you get a tune.

[pocket-rocket]

i've only seen this happen once and it went away. ill go see if gas comes out again.

Could it have been moisture in the exhaust from high humidity (you said it was raining) and not running for a while since you were trying to fix it? Or did you smell it and verify it really was fuel?

[SappySE107]

It adjusts fueling based on O2 feedback and adjusts spark via knock sensor feedback. At WOT, there is no O2 feedback. In open loop, there is no O2 feedback. I still don't know what cam you have to know how it should be acting right now. It is best to tune it when you are done if you don't have the ability to tune it yourself. You would have to tune it for injectors.

[Rootie524]

well crap. sorry if this has already been made clear..but until i can make it to the dyno or get a tune..will the PCM fix itself a tad to make it at least alittle better?

and if i need a tune..im going to wait till i port my heads, get the 3500 valves, 28lb injectors and all that good stuff.

and when i get headers and exhaust..that won't need a tune, will it? the PCM can learn little stuff like that, right?

[SappySE107]

volumetric efficiency is off, and your power enrichment would need to be changed on a dyno tune. Spark and other modifications could also show some improvements. Without datalogs, its all just a guess at what all needs to be done.

[Rootie524]

i've only seen this happen once and it went away. ill go see if gas comes out again. when it did it wasnt much just some small drops came out for a bit then as the car warmed up it went away. vcm suite is pretty expensive so i might try to find a shop that can tune.

what exactly is it that i need to get tuned? what's off?