Project 3400 Roller Cam Block (Page 70/82)
lou_dias JUL 27, 01:07 PM
stock rims weigh about 17.75 lbs with stock tires on and inflated, the wheel/tire package weighs 44.5 lbs each (15x7 215/60-R15).
my tires (315/35-R17) weigh 33.4 lbs. My current wheels are 17x9.5 but heavier than these new 17x10 wheels. I won't know the weight difference until I have the rubber dismounted. So it looks like my new combo will only be about 11 lbs heavier than stock per wheel+tire.
lou_dias DEC 22, 03:36 PM
Gonna be doing some surgery on the Trueleo intake.



A shame Trueleo didn't do their testing on ported heads. While these velocity stacks may help the stock 2.8, I think they have ended up being a restriction for my engine. Also, I'm finally removing the S neck that puts the throttle body infront of the decklid hinge so that I can run a proper cold air tube.
lou_dias DEC 22, 04:07 PM
ports still look clean on the head....
Blacktree DEC 22, 11:15 PM
The rounded ends on the velocity stacks significantly improve airflow. If you cut them back, you'll need to replicate the rounded ends, or you will lose port flow. If you're not careful, you could actually end up with worse port flow than you started with.

The graphic below illustrates what I'm talking about.
lou_dias DEC 23, 07:09 AM
But I think the fact that they sit in the tubes occupying space is a restriction overall. Remember, this is a 3.4 with a .040 over bore, not a 2.8. Also my heads flow much more than 150cfm... It probably does improve flow for a 2.8 but becomes a restriction for a 3.4... The 3.4 generates more vacuum. My peak HP is coming in about 300 rpm below two different cams' advertised peak. 4900 with the stock 3400 roller cam and 4600 with the 480/480 lift cam advertised at 4900. I'm using a 2.5" exhaust with 1 3/8" ports and primaries...so it's not the exhaust... This is the same motor that made 187rwhp/249 ft*lbs with the ported Fiero intake. I've made ~177/221 ft*lbs with this intake before putting on heavier wheels. My tune and timing is spot on so the only difference left is the intake. After cutting off the neck to have it the way I originally wanted (no S curve), multiple people looked inside and did not like the tubes. So time for some open-intake surgery...

[This message has been edited by lou_dias (edited 12-23-2016).]

Blacktree DEC 23, 09:20 AM
IMO, what you really need are larger diameter tubes and a larger plenum. So basically, the whole upper intake needs to be replaced. Talk to La Fiera for some ideas.
lou_dias DEC 23, 12:39 PM

quote
Originally posted by Blacktree:

IMO, what you really need are larger diameter tubes and a larger plenum. So basically, the whole upper intake needs to be replaced. Talk to La Fiera for some ideas.


My Formula daily driver also has a 3400 block but uses the stock ECM and Camaro 9.0 pistons...
It's using a ported Fiero intake (the upper I made 187/249 with) that now has the DAWG-mod and it runs like a champ. I still haven't dyno-tested it or done any tuning to it.
You're starting to make me want to switch back...now with the DAWG-mod it isn't crippled at 4200 rpm infront of a 3.4...

I'm hoping that the Trueleo tubes aren't a restriction and the the velocity stacks are just inserted in there lowering the inside diameter at the entrance of the tubes... I'm using a twin 42mm TB from a 91 V8 Firebird which is good for 400cfm...
Blacktree DEC 23, 01:04 PM
I think I know what you're talking about. You can probably fix that by widening the plenum. Try to imagine slicing it down the middle, and prying the two halves apart. That should give your velocity stacks more breathing room. Make it wide enough, and your throttle body can bolt right onto it.
pmbrunelle DEC 24, 01:59 AM
Cutting the trumpets flush will reduce the pressure drop in the plenum, but at the expense of increasing the pressure drop at the inlet of each runner.

Will the reduced pressure drop in the plenum make up for the loss in performance at the runner inlets?

If there are no significant gains to be had by opening up the plenum, it is silly to even think of chopping the trumpets.

To confirm that the plenum is indeed a bottleneck, I suggest you measure the pressure drop between runner #6 and runner #1. With a barb fitting at each end of the plenum, and a water-filled clear tube, you can have a passenger observe the pressure drop at WOT. 4 inches of water is approximately equal to 1 kPa.

Without measurements, you're blind.
lou_dias JAN 11, 03:27 PM
I've made the decision to ditch the Trueleo. I can't imagine how much surface rust is going thru the runner... Dug out my old middle intake...

http://www.youtube.com/watch?v=_zZB6THQ8R8

Also received a Firebird 2.8 upper intake that I'll be porting and shortening...