3.4 Boost Question

[MurderedMach]

So I traded my Gen two 2.9 for a Gen one 3.4


My pulley combo on my 2.9 was a 3.5 upper and a 6lb lower, and with longtubes and ported heads I saw about 20-21lbs.

Now with this gen one 3.4 what upper do I need to run to see 25 with the longtubes etc? This is a built engine and looking for 800 thru an auto with e85




Matt

 

[TRQJUNKIE]

I'm at about 18psi with 4.0 upper, stock lower, non Crusher, and stock manifolds. I believe every .2" pulley change is worth 2 psi so just try and figure it using that and how much pressure is decreased with your better flowing mods.

 

[testorossa1989]

.

 

[MurderedMach]

^

 

[03redfirevert.]

first of all,if you dont have the caged lower,put one on immediately,the stock lower and 3.5 upper would be around 24 psi,ported heads dont really affect it as much as cams,maybe 1/2 lb I would say the 3.5 upper with a 2 lb lower should get you to 25-26 and exceed that 800 rwhp #

 

[Jerry03cobra]

My old set up 3.4 w/crusher 3.4 rr upper stock lower 1 7/8 LT header ported heads stage 3 cams I was seeing 27 psi then it would drop to 24. I had all the idlers tensioner and I could not get the belt from slipping but I still got 903hp 857 tq on 110 gas. I sold all of that and now doing twin turbo.

 

[MurderedMach]

So I'm assuming the boost is all sorts of different from the 2.9 to the 3.4?

Like I mentioned I'm only seeing 20-21 with tr 3.5 and 6lb currently

 

[sam92lx]

Stock lower with a 4.0 I see roughly 20-21psi. With 3.5 upper I see 24-25psi all with 1 3/4 LT's. Just bought a 3.0 pulley so we'll see what happens.

 

[MurderedMach]

Looks like I need to change up my pulley combo. Was really loving the big tq numbers though

 

[TRQJUNKIE]

Looks like I need to change up my pulley combo. Was really loving the big tq numbers though

Is yours a Crusher or Standard inlet?

 

[MurderedMach]

Standard

 

[SN8KBYT_1]

I have a 3.20 pulley with the 3.4 whipple. 28 lbs of boost. Built motor. E85. Kooks long tubes. 792 at the rear wheels...

 

[MurderedMach]

Thru a stick?

 

[SN8KBYT_1]

Mine is a 6 speed...

 

[MurderedMach]

I want 800 thru my auto

 

[SN8KBYT_1]

I got you. Sorry. I would think you could still get to your goal with the right pulley and tune. My car made over 900 at the wheels but was detuned a bit. I have the MMR 900 block with stage 3 cams. Good luck. Would love to take a spin in a 800 rwhp auto! Good luck. We wanna see a dyno when you get it done...

 

[MurderedMach]

Thinking a 3.25 and stock lower

 

[SN8KBYT_1]

Should get u damn close...

 

[sabotage]

My 3.4 gen 1 with ported head stage 2 cams and a 3.5 upper stock lower I see 18lbs it made 791 rwhp on a a 3.2 pulley it would slike to 27 then come down to 23 lbs and it made the numbers on the sig

 

[MurderedMach]

We shall see what the 3.25 and stock lower nets me