I have pretty much the equivalent of the the 3076 in a Forced Performance housing in the form of an FP3052 on my DSM. I made 521 AWHP on straight 93 pump gas (no alky) with ignition problems up top on only 25-26psi. I was only seeing 70% or so duty cycle on 950's and had plenty of room to up the boost on pump gas with no knock as well. This was on a 2.3 stroker. This is definitely the pump gas record for that turbo and pretty close to the overall record.

 

I made 455whp on race gas with my 30r. There was just no more left in this turbo from what we saw. This was at 26psi, when upped the boost to 27psi we only gained .5whp, i decided to stop there as it was evident it wasnt going to make much more. Now thinking back i wish i had just ran one run at 30psi to see how it did, but there were 5 other cars that needed to be tuned. Mabey when i get to the track i will do a run at 26, then up it to 30psi to see the difference in trap.

The car is making 360whp 91 octane at about 20.5psi, a very conservative tune as i really dont care to push the car on pump fuel.

 

What backside did it have on it? 5bolt or 4bolt and what A/R was it.

 

It is the old 5bolt presicion housing RNR speaks of, with a .63. I am sure a .82 with 4 bolt conical discharge would make a bit more.

 

Really because I can spike 30-31 with mine and will taper to 27-28 at readline. Do you have the 3071 or 3076?

 

hmm... this is what freaks me out, i somtimes see these graphs of the full spool at 4500... but i know my friend running his 3052 with a staged head is making full boost by 3600... is that all in the head?

 

The more 'built' a head is, chances are will slow the spool down. Normally people will port the head but also portmatch them so the end result usually is just more power up top and usually slightly lower down low. The other thing about built heads are they normally use double springs and such, which technically lower the power of the motor but allow it to spin faster without floating.

 

My tune was with a MAF in front of the turbo and a tune NOT set on kill which has a lot to do with how a turbo spools. Alot of people to talk about spool are full of crap b/c they dident datalog the boost, they went by the "gee I looked at the guage and I think this is what it said" which is always wrong, I know b/c I did this also and was shocked when I got a way to actually log the boost verse rpm.

 

so i just won't be able to explain mark's 3800 full boost... i mean he's on aem too and that's what he uses to read his boost peak, can't be wrong.... that was on his 2 liter too... but then again maybe it was because he has an rnr road racing header. or something else....

oh yeah correction it's 3800... so typed it wrong the first time. but still... that's remarkably faster than 4600

 

Maybe and Maybe. You can build a head to increase flow at lower port velocity and lower lift to give you more torque/hp in the lower ranges and improve spool. Also when a head is modified a lot has to do with lower valve lift performance (in the .200+) range which can help with low rpm efficiency(spool).

Parasitic losses from a valve spring on our motors is pretty small (my guess a few hp), now take a 426 Hemi with a 310+ duration .680" lift roller cam with over 200lbs seat pressure and that will cost you a lot more. If you build them loose (low ring tension, higher clearance bearing, looser valve stem clearance) valve spring loss is one of the larger losses but our motor have a great tappet to lifter angle so the spring rates are not bad on the 4g63.

 

That's what I am saying, I had a maf in front of my turbo witch will slow down a turbo and he is probly running speed density so he has no maf. This alone will help spool immensely, so my point was to compare spool rates we should know what engine management they were running and the supporting mods.

 

with a post like your last i think i want to marry you..

 

When were you seeing full boost on your 3076? I am seeing full boost, via dsm link with maf, at 4500-4600 (21 lbs). I am also at almost 6000 ft above sea level though.

 

hmmm so there are still many factors to consider for spool...

 

Yes, exactly!