dmaxvaz

iTrader: (1)

Those of you with turbo cams- does it hurt driveability with higher duration on the exhaust side? Would lack of vacuum be an issue? I talked to comp cams about the cam specs that my engine builder installed in my engine, and the told me that the cam is the issue for the idle quality and lack of vacuum. any thoughts?
Engine specs: 390 ci, ported and polished 317 heads, edelbrock proflo xt, s480 with FI etr-ho billet wheel/ 1.32 exh hsg. Engine made 801 rwhp/ 684 rwtq @ 17.5 psi w/e85

dont have the cam specs in front of me, but i will post them up later

turbocamaro125

iTrader: (3)

LIL John will know what you need

HexenLord

You would have to post can specs. LSA/overlap play a far bigger part in driveability than individual durations. If someone is claiming a turbo cam is hurting idle and vacuum, they are selling you the wrong cam.

For example, look at the Lingenfelter GT9 cam. 215/247 duration, .629/656 lift. Not a small can by any means at all, but produces a smooth idle and enough vacuum to be daily driven.

http://www.lingenfelter.com/mm5/merc...gory_Code=P016

smokeshow

iTrader: (17)

Power definitely seems low for the displacement, turbo and boost level. Often times you'll find that cams that drive nicer often perform better with a turbo.

dmaxvaz

iTrader: (1)

.605 int, .608 exh lift, 238 int, 240 exh @ .050, 114 icl, cam was installed @ 110 icl

Unreal

It can as overlap goes up, driveability goes down.

Just got a turbo cam for a 416 TT setup, was pretty mild. 234/234 115+2. Goal is 1100rwhp. A bit small compared to my blower cam which is a 232/246 116+3.

That cam has 11 degrees of overlap which probably won't drive like stock but isn't that bad.

Forcefed86

iTrader: (4)

How much power do you want it to make? I see no need to have the duration that high. 11* of overlap. Could easily make 1000+ on much less duration with that setup and retain stock like driveability/idle. I'd look at a 218/218 112 ISKY cam. Using that cam Stock48 is well over the 1000whp mark on a stock 6.0 long block.

dmaxvaz

iTrader: (1)

I am maxxed out on injectors with e85 (1000 cc). it makes power, just idles like ****, 7 inhg vacuum, and i would have liked to have a little more tq

Forcefed86

iTrader: (4)

Right thats exactly what I'm saying. You are giving up a ton of low end with that cam. Swap it out for the above unit it would be a night and day difference. Idle would be nice as well.

I'm making more power than that on a stock 5.3 shortblock with an OEM ZR1 cam with .56x lift. (which isn't the best either) Though it does idle/drive just like stock. No need for a "huge" cam to make that kind of power... esp with 390ci.

dmaxvaz

iTrader: (1)

I wonder how the stage 2 tick ls2 cam would be (reverse split) in my 5000 lb tbss?

stock48

iTrader: (17)

The the longer stroke needs a little more cam than a std 6.0/370. I would keep it below 230 and lsa between 112-114. If it were me. Truck in sig has my triple 12 cam and makes 800 at the tire16psi on 91/meth with a cast 76. With race gas mix and more timing Was 936 sae locked at 20 psi and ran 9.73/@139.xx. Truck will sometimes bark all 4 tires off dead idle with no brake spool.

dmaxvaz

iTrader: (1)

How about this one: .600/.600 lift, 230/230 @ .050, and 115 lobe separation

ninetres

iTrader: (35)

It would idle better if it was installed at 114. Probably more power too....IMO.

MonmouthCtyLS7

iTrader: (6)

Drop Martin @ Tick Perm. a pm I'm sure he can lead you in the right direction.

dmaxvaz

iTrader: (1)

i did when i recieved the engine from the builder. He pm'd me back saying it should be good. I need to call him tommarow and talk cams

Fraser588

The funny part about this, you're making 801rwhp through a 4L80 and complaining about idle quality.

If making 800rwhp is what you want, you have the right cam.

If you want stock idle and 700rwhp, get a smaller cam.

shawnc16

He's not complaining about it as an idle quality stand point, Its the lack of vacuum that's the issue. No power assist for the brakes is a safety issue.

Fraser588

If you have stock like idle you will have 18-20" of vacuum, idle quality goes down so does the vacuum.

Another part though, that edelbrock intake manifold may not be great for low end torque, i'd consider trying an OE intake, just me.

In a light car the shift in power band from an intake runner change will not be noticeable, in a 5500lbs truck quite the contrary.

dmaxvaz

iTrader: (1)

ok, it must be my intake then. Riddle me this- I have been talking to another guy with a tbss (you guys built the 385 for him), he also has an edelbrock intake, has remote mount twins, 4l80e, and a cam spec'd by someone else : .600/.600, 230/230 and 115 lsa. He has no problem idling at 800 rpms, great vacuum, and makes more power than mine (946 hp), oh and has low end power. I guess he has a unicorn (only person to make low end power with a edelbrock proflo)

T/ALT1

iTrader: (3)

Looks like you should go with the smaller cam. Stock48 made 900+rwhp with the 212/212 and the TBSS makes 900+rwhp with smaller cam also . I would PM stock48 and get him to spec you a cam, he's been doing 5.3/6.0 turbo truck builds for awhile and makes a ton of low end power on all his builds.