onefastss223

iTrader: (14)

Alright, this is the deal. I just finished my new engine/setup and just trying to figure out if I have a boost problem. The new engine is a 408 at 9:1 CR with Patriot LQ9 2.08/1.60 valves and 222/230 .574/.580 114+4 lsa. I upgraded to the D1 blower while it was down and also added the EPP FMIC along with a DIY blower hat/intake setup from EPP and Procharger Race Valve. I also upgraded to the Kooks 1 7/8-2" 3 1/2" collector headers while i was building it.
I'm wondering if I'm seeing the right boost on this engine b/c I've lost ~3.5psi over the old engine. The other engine was 347 with same heads(2.02/1.57 valves, same cam, FLP LT's(no cats), and stock Procharger piping/intercoolers/P1SC/HKS BOV.
The most boost I've seen is 5 psi at ~5800 rpms or so. Belt slip is non-existant due to me running the SDCE 8-rib so I know thats not it. I've tried adjusting the RaceValve but to no avail. I've got it as tight as I can turn it with a ratchet and no improvement. The car is still running on a base tune so I have no dyno #'s/track times to help out. Any suggestions would be appreciated.

kp

iTrader: (34)

First off you dont want the bypass cranked all the way down tight, boost holds it shut not the spring. Cranking it down can delay it opeining a little which can blow off pipes etc..

2nd what pulley on the blower and you are only turining the motor to 5800?

But with the bigger headers and more cuobic inches I would expect to see a couple psi less then the 347.

Inspector12

iTrader: (29)

Don't compare the 347 to the 408 first off and the pullies are going to determine how fast and howmuch boost you will see just like KP is telling you. Good luck.
Jeff

NA$TY-TA

iTrader: (21)

Yep i agree %100...

Time for a smaller pulley.... and to spin the motor a lil higher......

onefastss223

iTrader: (14)

I understand that i will lose boost from the 408 being less restrictive and the bigger headers as well. I was just trying to figure out if 3.5psi was typical. I'm running a 3.4 BP and 7.25 CP. I plan on ordering a custom 7.75" CP from ASP in the next couple weeks to get the blower turning a little harder. I'm only turning to 5800 b/c its not fully tuned and I dont want to hurt anything. To be honest, it feels dead on the top end though almost like it stops pulling when it should be doing the exact opposite.

kp

iTrader: (34)

Thats spinning the D1 pretty well, I would maybe start thinking F1. But until you spin it up higher and get the tune dialed in its hard to tell. What kind of boost did you see with the 347 at 6500 or so with the 7.25/3.4?

onefastss223

iTrader: (14)

At 6500 it was seeing 8.5-9psi but for whatever reason it doesnt have the same feel up top the 347 did. I think alot of it is the tune just needs adjusting/dialing in and maybe b/c it feels pretty stout down low now too. I guess we'll see what it does when I get the blower cranked up some more and with a good tune. Im kicking myself for not upgrading to an F1 while it was down. I upgraded from the P1 to the D1 when I was still planning on running a 347 again. Bascially about 2 weeks before I decided to go 408. Are there many guys running F1's on street cars? I'm trying to keep my car as streetable as possible and cant imagine the F1 would make it that much more un-streetable.

kp

iTrader: (34)

Just the noise with the F1, gets up there pretty good. 9psi doesnt seem like much with that pulley combo unless you still have the stock intercoolers. I see over 15psi with the same size cam and big heads on a 347 around sea level. Maybe check the plenum and make sure it isnt cracked and make sure all the hoses are solid.

I would think the FMIC would be a cheaper and more effective upgrade path then an F1, especially if you still have the original 3.5 twin ICs. Except you have to cut the front of the car for the IC which is a bummer. I cant see putting a F1x on a the stock twins, kind of working against yourself there.

onefastss223

iTrader: (14)

I'm already running the EPP FMIC kit and a DIY EPP blower inlet/filter setup. I've checked all the pipes and its not leaking any where from what I can tell. Under throttle, it sounds like some of the boost is getting out at the bypass valve b/c I can still faintly here the venting sound.

kp

iTrader: (34)

you are runing the vacuum/boost line to the bypass correctly right? it depends on the boost to push the diaphram and keep it shut. If you are hearing something leaking then most likely something is. Did you swap to the FMIC with the 408 or it was there with the 347 too?

What is your elevation?

TS6

iTrader: (41)

Yeah, something is wrong. I run a 3.85 pulley on my 408 and make 13-14 psi, and thats with the stock inlet hat.

onefastss223

iTrader: (14)

Yes, everything is new. I ran the stock piping/plenum/intercoolers on the 347. The bypass vacuum line is plugged into where the old BPV plugged in. Im thinking that I may need to recheck all the connections to make sure their all tight. Not sure what the elevation is exactly but somewhere around 750-800 feet.

kp

iTrader: (34)

Make sure that bypass line is seeing boost. Also make sure one of the hoses isnt split or isnt on a pipe all the way and seperating under boost. Like I said if you can hear it then most likely something is leaking.

onefastss223

iTrader: (14)

You called it with the bypass line not seeing any boost. We moved some things around last night and made sure that the bypass line was seeing a good source of boost and its a completely different car. I saw 9psi at 6K last night and it was pulling hard up top! Thanks for the help in getting it squared away...

kp

iTrader: (34)

Thats cool it was a simple fix, have fun with it.

Drewstein

And make sure your tune is dialed in. You don't want to hurt a brand new motor!

Once it is spin that sucker to 6600rpm, so much more power to be had.

onefastss223

iTrader: (14)

Yeh, I'm trying to be easy on it. I havnt taken it over 6K rpms and dont plan to until the car is fully tuned. The wideband is reading right on 12.9-13.1 on the street all the way up so it'll be a few weeks before I can actually get on the car hard.

ty_ty13

iTrader: (42)

you dont need to take it over 3200rpms with that afr...

nvmy2000ss

iTrader: (17)

I could be wrong but isnt the ideal afr on a F/I motor 11.8 or so. Please correct me if Im wrong. I would think 13 is a bit high.

nvmy2000ss

iTrader: (17)

You got to it just b4 me