pbass

Engine mods: Injen CAI, Injen hotside, Dejon coldside, Treadstone TR8 IC, Treadstone DP with Bear River 79130 cat, BNR GT2860 turbo, GMS1, tune.

First dyno is car with stock turbo and without the IC and DP.

Remaining dynos are all listed mods. Low one is 17 PSI. Rest 22-24.











What is wrong? And what is that weird wiggle up top? All ideas, experiences and stories welcomed!

Shibito

Sounds like something's wrong in the tune. Only picking up 40whp and 60tq with a swap to a GT28?

How much boost on the GT28?

cardelino18

iTrader: (3)

dam... thats weird... who tuned it? also post a pic of the vcm chart.... u are on a VERY conservative tune, looks like ur still on stock timing... u should b making way more than that....

cardelino18

iTrader: (3)

lol SPECIALLY on a dynojet

HHRSSouth

Wasnt the BNR 2860 suppose to originally have a new compressor housing like the 2871?

Then he (Brian @ BNR) said he didn't think it would make any gains?

Maybe the K04 compressor housing is to small for the 2860 wheel and at that high of rpm is messing the air flow up top? choking it up top

My 2871 has a dip at 6.5k comparable to your little dip at 6.25k but then raises back up at 6.7k and pulls to 7k again.

You did make a 40 whp gain but you also raised the boost pressure up a good bit and added a DP. So how much power was made by the 2860 wheel vs. raising boost pressure/DP?

Terminator did say the 2860 turbo looks like it flowed about 2 lbs/min more.

So your not going to see huge gains, but you should definetly gain better flow/hp all the way across the board and higher up in the RPM band where the K04 drops off.

pbass

If you look at the lower power curve, you'll see the same weird dip, bump, notch and spike at the top as you see on the higher power curve, just not as pronounced. So the prob must be something that gets worse when you jam more air through it. Previously, James had suggested checking out the cat. Makes sense. Car's in PA. I'm sending a catless DP there to see if that smooths out that spot.

After that, I'm still thinking about the clutch being a general power robbing problem. The car doesn't make enough power to make a stock clutch slip if it's in good condition. But when I bought the car I was slipping the clutch way too much (trying to change my habits now). Anyway I'm worried that maybe the clutch is glazed. I think I smelled something burning while accelerating a couple times, and the shop owner thinks he smelled it a couple times while dynoing.

I know this means that as a starting point I assume there's nothing wrong with the tune or turbo. But I don't have any basis for thinking it's either of those.

drewbroo

iTrader: (2)

The 2860RS is supposed to be Superior on paper.... but the 2860RS hybrid, I cannot imagine flowing much more than a stock K04. The 2860RS is just the the K04+ part II IMO. Intentions are there. Everything looks great on paper. Then when you throw it on a dyno... disappointment.

pbass

Again, the Q is: What's wrong? And what's that weird-looking squiggle at the top?

peachpuff

Post an hptuners log, a picture of it isn't enough.

drewbroo

iTrader: (2)

The weird looking squiggle looks like the turbo returned to pushing the air that it should be pushing

pbass

Right. Any guesses as to what might momentarily stop it?

The mystery squiggle is present in all graphs...

drewbroo

iTrader: (2)

Are you on E85 or 93 Oct

Chevycobaltss3

iTrader: (2)

If your clutch is slipping your boost could actually ramp up a tad depending on boost setting. Also your cat can be clogged. Basically when your car boosts. It trys to push air out but cant and it ends up coming back into the combustion chamber. 3Rd if your car makes wot surge. Also check ure couplers including intake coupler to turbo..

HHRSSouth

That very well might do it, I had a ZZP Spun metal cat on when I dyno'd mine and got a little weird dip at 6.5k- 6.7k (nothing major like you had).

I switched to a Dejon catless (I would not recommend, build quality was cheap imo) that a friend let me borrow, logged it and gained 2 lbs/min more flow just by switching to it.

I have not dyno'd witht he catless on, just logged it.

Iam Broke

iTrader: (10)

Is CAT overtemp protection disabled? In a long hard pull it will make it run pig rich, like .75 lambda or so when calculated EGT's go high.

Need to know your PE Lambda ect. 0.88 PE Lambda would be a good place to start though.

Iam Broke

iTrader: (10)

Tune would be nice to look at also.

c1_c1rca

Therizinosaurus.... now thats a fucked up looking dyno... zebra looking mother ******

Wangspeed

iTrader: (2)

What he said. Log the commanded Lambda.

HHRSSouth

He was dyno tuned by a well respected/known HPT tuner for the LNF.

I will leave it up to him or the tuner to say who it was.

Just from what I know of the tuner, I highly doubt its the tune.

pbass

93

Chevycobaltss3

iTrader: (2)

it is good, It just needs to be figured out (no i did not tune him lol) But To me It seems like a cat issue.... Once the car warms up it gets worse or after long pulls. Theres no surge from what Op says, so the wiggly line could very much be air trying to pass through the cat, and the air that cant could be fluctuating.. ID HAVE TO SEE A FULL LOG... I say your tuner will figure it out but things like the downpipe not catted will do it.!

fakameanrepresent

iTrader: (4)

^listen to him

drewbroo

iTrader: (2)

I know how long was put into dyno tuning this car. Its not the tune, it is something mechanical. My guess could be something funky going on with the wastegate actuation. Also how is it holding boost?

pbass

Yeah, a LOT of tuning variations were tried so I agree, it is something mechanical. WG was left as Bryan set it. Catless DP will be installed this week.

HHRSSouth

I adjusted my wastegate actuator rod 2 threads longer myself just the other day. I was seeing 26 psi but spikes to 28.
I turned it 2 threads and now I get a good steady 25-26 psi.