LV , Mike's not generally open on weekends.
But, I honestly havent driven it since friday, I've been working my Arse off to get the dyno pit/shopfloor done so I can build the new addition.
Put it this way, I'm considering buying my own jackhammer. Rediculous boulders!
Gotta get it up before the snow flies! (just a month away)
Im going to go out for a ride tonight after dinner. I have to see if my new cam timing map alleviates the surge @20psi 3000-4000rpm.
If you run 18psi it doenst happen. If you floor it from 3K it doenst happen. But pull 4th from 2000rpm@23psi and it's there everytime for just 1K rpm and is gone. It's not acceptable to run in surge.
I wrote a boost map that was 19psi until 4K then 23psi until 7400. No surge. What irks me is that when plotted on the comprssor map it's in a great area. well away from the dark black line.
Makes no sense, but I'll figure it out.
It could be that Im all stock and corked up a bit. The GT30R didnt have a CAT to contend with.
BTF, what's the exact cause of surge? IE, what's the air doing and why?
Definitely pull the stock exhaust... even if it's not part of the surge cause, it's still gotta be hurting efficiency.
wow how did it take me this long to find this one.....oh yea i've been out of power for 2 freakin' weeks LOL
did anyone hear any info from dejon about a tune for this baby yet, i am planning on going to biloxi, ms for cruisin on the coast the second week of october, is there any way to have this done and installed by then??
I dont see why not.. The turnaround time on the machine work is pretty fast.
From the garrett website:
The surge region, located on the left-hand side of the compressor map, is an area of flow instability typically caused by compressor inducer stall. The turbo should be sized so that the engine does not operate in the surge range. When turbochargers operate in surge for long periods of time, bearing failures may occur.
Whats buggin the hell out of me is that I shouldnt be anywhere near surge. BUt my ears dont lie..
I have it narrowed down to just a few hundred rpm. hopefully I can tune the rest out.
Last edited by BaldTurboFreak : 09-15-2008 at 07:30 AM.
How you making out Brother?
I hope the winds were kind to your home and your family is safe!
You want this little baby snail after I get the dyno #'s off it?
Made it through this one ok, one of the neighbors is missing 1/3 of his house, tornadas are a B@tch!. It is amazing his kitchen looks like a movie set 2 walls one corner and all the stuff on the counter tops, didnt even knock over the fridge, yet his roof and dining room are completely gone.
I still have the solstice packed away in the shop, in front of the G5 all the pool and patio cr@p. I have been working nonstop for the last 21 days between evacuations/recovery/evacuations/recovery it is starting to get old. One word of advice, fill up today, tomorrow the price will be differant.
To my Sol brother down in Houma, pm me if you have any needs from this end. I have a few connections between here and there.
__________________
It WAS Cool, Leather, XM, Monsoon and different! :)
wow how did it take me this long to find this one.....oh yea i've been out of power for 2 freakin' weeks LOL
did anyone hear any info from dejon about a tune for this baby yet, i am planning on going to biloxi, ms for cruisin on the coast the second week of october, is there any way to have this done and installed by then??
Well maybe you can ask Dave to take advantage of having my turbo and this way when you are ready to do yours in October, he will have the tune all check out and ready to do one for you.
BTF.
Definitely get your Dyno in place, to bad some of us do not live closer and try to help out getting things organise.
By the way DHL should have the turbocharger at your place tomorrow.
Also 2 of the tuners are ready to go when you have the turbocharger upgraded and Swaintech.
Please see if Dave and Westers can get on board. There are probably a lot of members that would like for them to offer this product with their tune.
__________________ Aggressive GXP at $25,995.00 shipping of $600, MT.
Options:
Air, $960; Chrome Wheels, $545; PCQ, Premium Package (Leather), $525; Radio, 6-Disc with MP3, $495; Monsoon, $395; Premium Acoustic Headliner, $150; and Sport Metallic Pedals, $115; all totals $29,180.00. No XM/OnStar and NO Spoiler. MODS (Magnaflow 2.5", BTF Turbo Upgrade wheel,DDM BB,ProBean&tune, K&N filter, Ventureshield.
First 1000. Aggressive with everything, NO XM/OnStar. SOLD
~~~~~~~ NASSOA
Founding member
~~~~~~~
Last edited by LatinVenom : 09-15-2008 at 09:45 AM.
The Garrett explanation didn't really describe what's specifically going on with the air. "Flow instability caused by inducer stall" still doesn't mean much to me.
But I ran across this explanation. And interestingly, it's specifically related to increasing inducer size without enlarging the exducer:
"The real trouble with a large inducer increase but no exducer increase, though, is it makes the turbo much more likely to surge. Surge is the situation when the compressor "spits out" more air than the engine can swallow, which causes a backup of air at the intake and it actually creates reverse-flowing pressure waves that can be very damaging to the turbo."
Thats a very good explaniation of the effect of trim on a compressor wheel.
To add to it the A/R of the compressor cover has the effect of widening or narrowing (peaking) the map as well.
Next step may be to extrude hone the compressor cover for a larger A/R.(fatten the map for more flow/less surge)
I wonder if much of the issue is that the turbine section is corking the motor... this combined with more flow from the compressor section causing surge.
BTF,
Now that you will have my turbocharger this is a good time to compare notes with one of the tuners. You have yours installed and they will have mine to test and try to come up with the best mods to our KO4.
Maybe now the membership will get an idea of why I put forth my plan to get this going.
__________________ Aggressive GXP at $25,995.00 shipping of $600, MT.
Options:
Air, $960; Chrome Wheels, $545; PCQ, Premium Package (Leather), $525; Radio, 6-Disc with MP3, $495; Monsoon, $395; Premium Acoustic Headliner, $150; and Sport Metallic Pedals, $115; all totals $29,180.00. No XM/OnStar and NO Spoiler. MODS (Magnaflow 2.5", BTF Turbo Upgrade wheel,DDM BB,ProBean&tune, K&N filter, Ventureshield.
First 1000. Aggressive with everything, NO XM/OnStar. SOLD
~~~~~~~ NASSOA
Founding member
~~~~~~~
I wonder if much of the issue is that the turbine section is corking the motor... this combined with more flow from the compressor section causing surge.
Naw cant be. It goes away with rpm.
What I find so odd is that I can make 22psi at 2500 and it's fine. THen in a window only about 800rpm it surges like crazy, then goes away and pulls clean.
THis just doesnt make sense if you understand the path the flow is taking across the map.
It basically means it has a "pocket island" in the map. Unless it's someting simple Im missing.
Naw cant be. It goes away with rpm.
What I find so odd is that I can make 22psi at 2500 and it's fine. THen in a window only about 800rpm it surges like crazy, then goes away and pulls clean.
THis just doesnt make sense if you understand the path the flow is taking across the map.
It basically means it has a "pocket island" in the map. Unless it's someting simple Im missing.
That last definition sounds very similar to hydraulic or electrical resonance. With electrical resonance there is a tuning point where the system displays an extreme impedance to certain waveforms (harmonics). It is a very narrow range and does not exist out of that range.
I’m guessing as a private pilot, the turbine blade angle of attack is insufficient to provide lift/spin until the speed of exhaust flow overcomes the load generated by the compressor. Essentially the exhaust flow begins to separate off the surface flow of the turbine blades because the blades can’t spin with the amount of load that they carry through the compressor shaft, only until the exhaust flow increases the lift of the blades causing them to efficiently spin again can they turn the shaft.
It sounds like the turbine is too small for the larger compressor wheel.
__________________
2008 Black/Black GXP, purchased 7/23 right off the train.
Mod#1 blacked-out headlights
Mod#2 GMPP Intake -I like to hear my turbo.
Mod#3 Special Sauce (23PSI)
Mod#4 Solo Street Race
Mod#5 Repaint w/ Custom Silver Stripes
'07 Charger R/T Mama's car
If that were so Id be having real difficulties with boost creep and I'm not.
It also would continue to happen and get worse in the upper RPM band. It's not.
I have reduced it to a small area with cam timing changes. or you can run 18psi and never know about it.
But Im an engineer, and engineers get extremely annoyed and inquisitive as to why the real word data is miles off the math.
Im going to get to the bottom of this.
The AutoGuide.com network consists of the largest network of enthusiast-owned enthusiast-operated automotive communities.
AutoGuide.com provides the latest car reviews, auto show coverage, new car prices, and automotive news. The AutoGuide network operates more than 100 automotive forums where our users consult peers for shopping information and advice, and share opinions as a community.
Linear Mode
