roortube's UrS6 Avant...now playing with Alfas

[mushasho]

Graphs?

[glibobbo21]

Hey its jim. Good to meet you guys. Glad you made it home safe!

[roortube]

Hey Jim...great to meet you too. You guys are straight up nuts with the scope of projects you have going on up there. Cool people too. I just read most of your thread...now those header pics you showed me make more sense. Good luck with that.

We did have a close call on the way home when there was a car stopped with its lights off in the right lane of the Jersey turn pike that almost caused a 10+ car pile up, and another when an 18 Wheeler creamed a deer just in front of us on895 in Maryland. Good thing I was awake and jacked on coffee and red bull or I may have reacted too slowly!

Obi, Marc is away this week and has the graphs in his office. He's going to send them to me when he gets back.

[roortube]

Cam timing is dead nuts perfect verified by timing marks and by an extension on piston 1 looking for rise and fall in relation to cam timing mark. The belt was a hair loose, maybe 95-98 degrees of rotation on the long run. I snugged it up. Think maybe that was allowing for things to get out of window at high revs/load? Marc said things were getting a little weird on the dyno around 6k rpm in that he was requesting the N75 to increase duty cycle and it would delay it's response. He said that there's a function in the software that does this if hall falls out of window. If this is whats happening it may also explain the late spool we were seeing, with spool occuring around 5k rather than 4k where Hank was predicting it would be.

[Hank]

5k spool would surprise the heck out of me, as that turbo is just slightly bigger than an gtx3576r, but significantly smaller than gt3582r. Perhaps I'll bring a HTA3582r with me to Carlisle on carry on for a preferred customer with a turbo capable of being swapped in 20 minutes

[mushasho]

5k spool would surprise the heck out of me, as that turbo is just slightly bigger than an gtx3576r, but significantly smaller than gt3582r. Perhaps I'll bring a HTA3582r with me to Carlisle on carry on for a preferred customer with a turbo capable of being swapped in 20 minutes

Oh the benefits!!!

[roortube]

That'd be cool, but would require a retune right? I'd like some advise from you and Marc re things to check with my car before condemning the turbo.

Oh, BTW...I have an extra tent and sleeping bag if you still need...

[chaloux]

Hmm, 5k eh. Maybe keeping my gtx76 a 30r turbine and going 1.0 hotside with qsv is the answer then. Maybe I'll have to try both that and a 3576 with .82 and qsv, lol.

[mushasho]

Though it will spool quick in it, you'll never extract full potential of that Billet GTX 58mm wheel with that 30R. Doesn't matter how big of a housing you place that 30r turbine in... Then again, maybe that's what you're after, which in that case, you're on the money.

But then again it contradicts:

[roortube]

Just so we're all on the same page here...this turbo doesn't have any lag to speak of. Once in operating range it will built full boost almost instantly. It is currently only operating well up in revs though. Chatting with Marc he still suspects a timing window issue. He's asked about the cam and crank cogs, but both are good. His current thoughts are towards the flywheel reference, although the sender is new and the flywheel was at JB for a rebuild and check prior to installation. He only thing I haven't checked timing wise is cams in relation to each other, but that was dead on when we built the motor. I had a valve cover gasket delivered to work today and will check relative can timing soon.

[drwho]

Sounds good, I'm sure when we put it together it wad right but maybe there is something we can do with the cams

[roortube]

With a week of driving this turbo under my belt I feel that I can give an honest assessment of this setup. If you want a stop light monster, this isn't for you. Below 3500rpm the car feels like it has a 2.0 8v under hood. Things change at 3500 and from there to about 4500rpm depending on the gear the car feels a lot like my wife's C5 S6 4.2L V8 in terms of response and power at the same engine speed. Above 4500rpm it gets I retreating and you'd better be paying attention to what's happening. 5k-8k this thing rips. On Wednesday I took a pair of SBC heads to my machinist. They were sitting flat on the carpet in the trunk and when I caught boost they rolled over and cracked the plastic trim inside the tail gate. Woot.

I actually kind of like the power band this way, because you only go fast when you mean to, and anybody can drive the car with out feeling intimidated if they keep the revs down. I haven't posted plots yet because Marc hasn't sent them to me, but I recall that the curves were pretty much flat from 5k to red line.

Fuel economy has also been improved to an average 23.5 mpg.

Now and again when I drop the car in neutral from cruise the revs drop to the point that the engine stalls, which sucks. I have no air leaks, the ISV is clean and working, and the throttle damper is new, so I dunno what's causing this, but I need to fix it.

[drwho]

Maybe something with response rate of the air density boost signal line or maybe air temp sensor needs cleaned just a thought

[mushasho]

the motivation is a prick near my work with a murcielago who needs to be out accelerated by an old wagon. dude is a jerk...im gonna get him to 160 before Im done.

So how's the prick doing?

[roortube]

I'm not ready for him yet Obi...baby steps. I'll get there though. By that point he may have something crazy like a Huayra though.

[Marc]

Sorry for the delay on getting you the graphs Rob. I was away at lemons this weekend. the boost curve will be improved with N75 control once the drop-out is sorted (I still suspect some form of cam offset problem). As you can see here, the manual boost controller thats in there isn't holding boost very flat.

[chaloux]

6k! Something is wonky dude.

[loxxrider]

That is when my HX52 (aka huge diesel turbo) was getting 25 psi. Something is definitely wonky! I'm sure it is still fun though!

Just because your ISV is working doesn't mean it is "tuned" right in VEMS. Check out the PID values for the ISV and tweak them a bit (if you know how to). That should help you out the most. If you dont' know how to, just increase "P" a little and see what it does. It may send it into doing some oscillation at which point you should back off and adjust some other things which I can explain to you if you don't know how.

[Marc]

That is when my HX52 (aka huge diesel turbo) was getting 25 psi. Something is definitely wonky! I'm sure it is still fun though!

Just because your ISV is working doesn't mean it is "tuned" right in VEMS. Check out the PID values for the ISV and tweak them a bit (if you know how to). That should help you out the most. If you dont' know how to, just increase "P" a little and see what it does. It may send it into doing some oscillation at which point you should back off and adjust some other things which I can explain to you if you don't know how.

its motronic Chris. I suspect there is just a decel cell in the map I need to retouch, going a bit rich or lean causing a stumble. I'll bring my gear with me and check it at Carlisle.

[loxxrider]

Ah, that shows how out of touch I am with this project. I gotta get used to the idea of these cars getting motronic tunes now! See you at Carlisle

[Hank]

Easy with freaking out on the "dyno says I am getting full boost by 6000rpm" mindset. If you overlap this with a HTA3582r like Ed's that was performed on the same dyno, the similarly sized wheels(HTA3582r 59.5mm and this 60-1 59mm wheel) manage to spool very close to eachother. Dynos are ultimate tools for calibration and simulating load, but they do not ever 100% represent road conditions.

My own 2.2L on e85 in 4th gear


Vs my dyno in 4th gear.




25psi and 400whp is probably 30-40whp less than what I would have guessed, but there are other variables to consider. I have been high on e85 for to long to make rational estimation of power!

[EDIGREG]

That is true but note that we had a known final drive calibration issue (didn't calibrate) with my car...which explains why it was showing so late on the dyno graph. I don't think that is the case for Rob's car. Coupled with his description of "below 3500rpm the car feels like it has a 2.0 8v under hood" makes me think there is actually something wrong.

Fortunately in my case it is easy to compare the VEMS logs with the dyno logs and see that there is a clear disconnect (dyno was seeing 8000 rpm while the actual rpm was 6500).

[Hank]

Right, but that would reflect less HP than indicated. If you run the formula for HP( RPMxtorque/5252) you will see that while spool would improve incrementally on an incorrect cal, hp would decrease. Also it would not be a 1500 increase in spool as it would be a ratio, much like a MPH gap in ratios as you increase engine speed.

I too think there is something wonky going on with Robs car. 5000 RPM street spool is still unacceptable to me for those sizes of wheels.

[EDIGREG]

Yes, but it was nowhere close to a complete tune. We stopped as soon as we discovered the fuel pressure issue, never got to tune boost and didn't even touch the spark map. That plus the calibration issue make the numbers irrelevant/useless.

Don't know what the dyno "should" have shown for spool, but it should be wayyy to the left. Maybe even more than 1500rpms - dyno shows 30psi @ about 6,100rpms while my street log shows 30psi @ 3,850rpms (both 4th gear). There were changes to the boost settings after the dyno though, so it is a combination of factors.

Should be getting back on the dyno sometime this summer, //sfest in August at the latest.

[mushasho]

my street log shows 30psi @ 3,850rpms (both 4th gear).]

Now this sounds like fun on the street...