GUITARJUNKIE28

ignore the afr stuff for now...this was supposed to be a preliminary. i'm still having issues with the 550/1600 staging on the microtech.

anyhoo, it made 11 psi @ 6k rpm's.... (did the turbo guy clip the turbine too much?)
that boost fell to 6-7 psi @ 7k-7500 rpm
hp was more or less a flat line in that area.

here's the story with the turbo:
stock s5 based hybrid with clipped turbine, unknown compressor, but it's the stock compressor housing just bored out, so it can't be that big.


here's what i've done so far...
started at 6psi set up like stock

installed the profec...no difference until it was set at 95%, then we got like 8-9 psi
ok...moving along.

took a vacuum t and gave it a 6mm bleed line so it would see less boost...
8-9 psi

what the hell...put in a restrictor
8-9 psi

ahhh.... clamped another spring on the wastegate actuator...
10 psi whoopie!!!

heavier spring...
11-12 psi...

heavier...no difference

so this thing just absolutely will not make more than 11-12 psi.

so judging by the dismal spoolup time and the flat line hp up at the top, would it sound reasonable if i said that this compressor is just plain maxed out?

GUITARJUNKIE28

oh yea,
maybe he ported the wastegate too big. that might account for some of the spoolup.

and i did try pulling the vac. line off the wastegate actuator completely...no difference.

and i should have mentioned it's a cosmo 2 rotor with a big streetport.

FB II

any boost leaks?

GUITARJUNKIE28

nope.

nyt

iTrader: (1)

seems like your turbo was clipped too much.

even a stock turbo was able to churn out 15+ psi when i had one

11psi from a turbo of that nature at 6000rpm is absurd

Wargasm

Yeah sounds to me like the turbine is not harnessing enough power from the exhaust stream to make the compressor go.

*edit* The slow spoolup makes me think he clipped too much on the turbine, and the flatline HP up top is telling me the compressor is also a problem.

If you want decent power, don't mess with the stock turbo at all, just put a 60-1 on there with a P trim 1.00 A/R housing.

GUITARJUNKIE28

my thoughts exactly! i just wanted to get a few more opinions in case i missed something.

just because it was brought up.... this is definately NOT my turbo. (had ot defend my honor )

car got brought to my house with a microtech and that turbo. i have to do what i'm told. but the owner is planning on using this as a drag car. his budget just didn't permit a big turbo right now.

oh well, it's enough power to have fun with. i'll finish tuning it like it is and let him have some fun thrashin' on it. then later on this year or next, he might go ahead and hit up a t66, gt40 or whatever.

but hey, pull the line off the wastegate and you save some money on a boost controller

BLUE TII

iTrader: (9)

Several people have had this problem with stock hybrid turbos.

One owner found that the ported wastegates' flapper was being pushed open by the high manifold to turbo exhaust pressures (ouch!) He added a spring between the wastegate actuator and the flapper.

Others have re-drilled a new hole in the wastegates' actuator to put more spring tension on the flapper.

Another cause of this slow spool on stock hybrids that has been identified and remedied on this forum has been poor tuning.

Make sure the ignition is set to correct degree and you have lots of spark advance in the vacuum areas- well, you know the tuning side of things...

GUITARJUNKIE28

tuning is nowhere near complete, but it's ballpark enough. but even that wouldn't account for a few thousand rpm's.
advance was pretty conservative, i'll admit that. ~30-32 degrees in some vacuum areas, but around 25 degrees when it stages ~2psi. i dropped the timing in that area just to make it a bit safer when it hiccups. when i figure out how to make it stage properly, i'll put the timing back, but i doubt it'll do anything drastic with the spoolup.

GUITARJUNKIE28

i just got sent the invoice...

it says 375-385 whp.... you think maybe they meant 275-285? maybe i'll have to pop off the front housing and measure it.

i'll see if i can post it up tomorrow. it says it's a t04E 57 trim.

BLUE TII

iTrader: (9)

You stated to ignore the AFR on the dyno plot, but...

If that was actual AFR I would see that as a large part of the problem- way too lean when the turbo should be spooling.

I would run lots of advance in vacuum and 13:1 tapering to 12:1 AFR and as mani pressure reaches atmospheric get aggressive w/ retarding the timing and richen up to 9:1 to 11:1 AFR (depending on what the ignition system can handle w/ out misfire). Go w/ a close trailing split as well in this transitional area and then widen the spit and advance the timing back to normal and AFR to 11:1 again as boost comes on (retarded to safe levels as boost rises).

This gives you a higher EGT in the transition to boost and will get the turbo moving. Keep the transitional area just as boost is comming on and the elevated EGTs won't cause problems.

BLUE TII

iTrader: (9)

You should be able to get it spooling fast, but it will still suck on top as the ported comso plates are HUGE and the T04E 57 trim is too small and loses efficiency since it is stuffed in a bored stock housing.

Cheap upgrade would be T04 60-1 or 62-1 in T04B 60-1 HiFi housing.

It will still be a little wheezy on the bottom since the cosmo intake ports are so big, but the top end will be better. I have seen 3rd gens w/ S5 stock hybrids post 377RWHP.

BLUE TII

iTrader: (9)

You stated to ignore the AFR on the dyno plot, but...

If that was actual AFR I would see that as a large part of the problem- way too lean when the turbo should be spooling.

I would run lots of advance in vacuum and 13:1 tapering to 12:1 AFR and as mani pressure reaches atmospheric get aggressive w/ retarding the timing and richen up to 9:1 to 11:1 AFR (depending on what the ignition system can handle w/ out misfire). Go w/ a close trailing split as well in this transitional area and then widen the spit and advance the timing back to normal and AFR to 11:1 again as boost comes on (retarded to safe levels as boost rises).

This gives you a higher EGT in the transition to boost and will get the turbo moving. Keep the transitional area just as boost is comming on and the elevated EGTs won't cause problems.

GUITARJUNKIE28

i know i can get it spooling faster, but i'm not gonna knock 2-3k off the spoolup time. i'm waiting to hear back on what's gonna happen to this thing. when its fate is decided, i'll either take it off or tune it. i can more than likely get 300 to the wheels. timing was conservative and it had a pretty big split.

but where you're talking about the 13:1 thing--did you notice it dip rich off the chart right after? that's the staging issue. if you look right before that, you'll see it in the low 12's. i dunno about running it into the 9's... have you noticed any incredible gains by doing it that way? it's not worth 100rpm to me.

BLUE TII

iTrader: (9)

Once my ignition system was up to the task, the only time I noticed running rich costing me power in the seat of the pants was running richer than 8:1 AFR.

Running pig rich and retarded helped spool 500-1,000rpm for me.

Every port had different AFR needs, but I imagine a large ported Cosmo port needs to be rich rich since it won't have good atomization, chamber fill (velocity) or resonance.

GUITARJUNKIE28

the primaries are medium, it's just the secondaries that are heaping.

i'll try what you said and see what kind of difference it makes. it's kinda on the other end of what most guys say--leaner with more timing to get the egt's up. it's definately safer your way, although less efficient. but all that set aside, he's pissed at the total power, so the turbo will more than likely come off and get swapped out for something else. i think that hifi 60-1 hybrid would probably be the best candidate. but i kinda wish he'd just deal with the hp for now since we were planning on going with the big turbo later on in the year. no sense in upgrading twice.

thanks for the help man.

BLUE TII

iTrader: (9)

The rich mixture and retarded timing during spool-up actually raises EGTs very high due to all the unburnt exhaust gasses expanding (combusting) between the rotor and turbo during the exhaust phase. The close split timing actually increases the chance of misfire so you dump even more fuel in the exhaust.

It is cheapo anti-lag, make sure it is in the small area of the map in the rpms the turbo is spooling and the load is high (low vacuum) so the high EGTs don't affect reliability. In normal driving you will blip through the area fast in lower gears and keep things cool, but if you load it up in a higher gear and dwell in that map segment or just spool many times in series (auto-x) EGTs become elevated. Lots of flames.


Just stock Cosmo ports are HUGE compared to S4 or S5 TII intake ports that the TII hybrid turbos usually are used on. The 13BREW and even more so the 13BRE used very fast spooling sequential turbos to provide the low rpm torque their big intake ports would otherwise limit. Compare 13BT primary ports/runners to 13BREW and 13BRE...

A 13BREW/13BRE will lack low rpm torque before boost comes on compared to a 13BT- mostly noticeable on single turbo conversions.

GUITARJUNKIE28

the ports aren't that big. it's just the runners-which creates a big venturi...so wouldn't that help the low end?

i've never measured the degrees, but just by looking at things, i think the primaries have a little less overlap in the re's than the rew or fc motors.