Ok i know that :

-Stock lt1 with stock spring and cam should be shift around 5000rpm(higher than that is useless)
-Stock lt1 with LT4 spring and stock cam should be shift around 5500rpm(higher than that is useless)


But what about a complete LT4 engine, at what rpm should it be shift since the cam spec change a little and the heads flow also a little bit more?

Intake lift- .476"

Exhaust lift- .480"

Intake duration @ .050" - 203 degrees

Exhaust duration @ .050" - 210 degrees

 

I'd say shifting at 6,000 rpm would be optimal. It all depends on how the dyno graph looks.

 

Not remotely correct.


If you want to learn something about optimal shift points just google for it. There are plenty of good web pages out there on the subject.

 

the LT1 still pulls hard past 5000rpm...shift there would be rediculous.

talk about granny shifting.

shift it at about 6000...just before the rev limiter kicks on.

and if the LT4 has the same rev limit...do the same with that.

 

Wouldnt this info be on your cam card or listed with the cam specs? I mean it really isnt that hard to figure out. It simply lists when power starts (RPM) and ends (RPM). Without looking at a dyno sheet for your car specifically how would you have anything else to go off of? OBTW all of those supporting mods, and no cam yet?

 

In my mind you must make the car handle well and brake really well before even thinking about adding some power(pure logic).

Now that my car handle and brake like crazy im leaning toward power My engine hydrolock so i just bought a brand new LT4 GM crate engin.This is why i was asking for shift point.

 

Dont get me wrong I believe that your setup is going a nice direction. I would just figure that it would kinda suck with all of that potential and nothing to back it up. Out of curiosity, what kind of times have you ran with the stock cam? IMO I can recommend the CC503, I think this is a good medium sized cam for street.

 

Well i will take my car to the track only when its gonna be at my taste, and by the way i am more a auto x racer than drag.

I encounter so much problem and i only put maybe 3000miles in 2 years.Im a little crazy sometimes so i ve changed everything that i didnt like(wich is a lot of parts),then my 10bolts explode and now after a bad ewp(overheathing) the engine hydrolock.

The only part that i didnt change is the t56.

So now i will run the engine in his stock version,with the lt4 cam(stock 330hp/340tq) with all the bolt ons and try to reach the max that this combo can give me.I need reliability because i got other priority in life(family/house).

 

I wish I had that kind of self-control.

 

HA! same

 

Well i could present you my wife...She is really sweet to let me put so much money on my car(all my sig mods + other maintenance things ) in less than 1 1/2 year.

When i told her that my engine was shot she was a little mad because were buying a house and there was no way that i could by a forged 383 stroker that could give me 450whp and still have enough room for mortage payment and live normaly.

She gave me 2 choices,put the car in storage for a couple of year or find a cheaper realiable solution.

I ve decide to buy a new engine to be able to run the car and have fun.But dont worry about me, in a couple of years i ll have new power plant

 

whipped......



























j/p always faster

 

Sounds like a pretty cool wife to me with $6k+ in mods spent in 18 months, it's just the way you said 'she gave me 2 choices....' I'da said something more like 'since I wanted a bigger garage with the new house...' It's all in the presentation!

 

I shift my stocker at 6500 for my best times.I dont really know how accurate the factory tach is though.Had the car over a year with plenty of hard runs under her without any problems so far.Also the car has 155,000 miles on the engine.We all know they eventually break something but thats just an excuse to mod it more.

 

your going in the right direction with those mods, keep it up
having the LT4 crate will help too, the block is a 4bolt main unlike the 2 bolt main LT1s, and the heads give u a lot more to work with for porting/polishing.