dbs1

I recently installed a tvs 1900 on my 07 nbs chevy max with the 6.0 (Thx Joe @ left coast).

We started with a 3.2 pulley when dyno tuning in the Phx area and dropped to a 3.1 to get 6+ lbs of boost, and a 100 hp add at the wheels (LT's & cat back.) It was hotter than hades there for sure.

When I brought it home at 7000ft elev it would'nt make 3 lbs of boost so I dropped it to a 2.9 pulley, where it finally pulled a little over 5 lbs.

Joe got me a 2.8 pulley and with 70 degrees I finally got the truck up to 6.3 lbs of boost, but truthfully it feels very weak even at that. Granted, with dod and the stock cam it has never had much low end, but it seems it should make more boost or wake up more. In Phx with the 2.9 it made 8.8 lbs of boost at 95 degrees. I'm using an aeroforce digital gauge, and not sure if the boost numbers are just off, but the sotp says no.

Is this belt slip, heat, elevation or a combination, or is there something else I should look for? (Any way to quiet that whistle down-it's LOUD) 4th sc and it's got the whistle award for sure.

SuperchargedSS

iTrader: (24)

mine is very quiet until you mash the pedal. I am running a 3.4 pulley at 7psi down here in South Florida. My crank is pinned. I don't think I have any belt slip, truck runs like a raped ape!

Spoolin

iTrader: (8)

That's really weird!! Those 1900's are really quiet, at least the few that I've been in!

BigCountryx

iTrader: (3)

hmmm, something sounds off if you are getting a loud whistle from a TVS, mine is quiet as stock and pulled 5.5lbs on my LQ9 with a 3.4" pulley. My boost gauge went out so not sure how much boost the 3.1" is giving me, but it pulls like an SOB. Maybe you've got a leak somewhere.

mike mcginnis

My guess is it has alot to do with elevation, as for the loudness, my guess is you are spinning it faster to make up for lost boost causing more noise.

zippy

I agree, the noise is likely from the rpm you're spinning it at and not from the boost. Although a whistle noise is an odd way to describe it. They are normally very quiet except on tip in. Can you post a video with the noise? You'll likely need to have it re-tuned for the difference in altitude. The faster you spin the blower, the more parasitic drag you create. On top of losing boost and losing your point of zero for boost you are taking more power to spin the blower to get it back to a decent boost number. Your truck would have been a good case for a TVS2300 just to not need to spin it too hard to compensate for the altitude. Do you have a way to check timing and AFR?

dbs1

The guys that did the tune in Phx have been pretty good to me over the years, (and I to them with well over $50,000 spent there in 6 years) so they are gonna try to bring the "tune board" up on the mtn and see if we can get a better handle on it.

I've had 3 different trd chargers on toyos and a whipple pushing 10lbs of boost on my old C3 truck, but again-no whistle this loud and I would only see a drop of 1-2 lbs tops from Phx to here.

Something sure does'nt seem just right. (besides me) It's also got a fluctuating/surge to it at part throttle. I was told it was something to do with the headers, but I'm not so sure about that. does not seem to do it in Phx, just traveling up to elevation, and while driving here.

zippy

That really does sound odd.

the slo1

it sounds to me like you have a boost leak, but i'm used to turbos. check all the vac/boost lines for cuts or ones that blew off, and the blow off valve to make sure it's not stuck part the way open.

leftcoast32

iTrader: (4)

There are different thing that all come into play here. Elevation, Heat and the VVT. The cam could be changed for one that is much better for boost and not economy. The elevation and heat are playing hell with the boost and power.