thoughts on my dyno and turbo size

[Robocop]

just dynoed the m30 yesterday why not.

it's stock, has a cam and 3angle valves.
the 58mm hx40. 3'' exhaust on e85. big ring gap.
between 13psi ramped to 16psi to save the clutch.

The guy said that it was running out of turbo up top
maybe he's right because on the last engine, stock cam, it wouldn't feel faster after 20psi and i took it all the way to 30psi.
ya i can do 20psi straight across and get allot more power but it seems to always fall at 6k.


So is this guy BS or wat u think?

466hp by jet jones, on Flickr
466hp-boost by jet jones, on Flickr

i'm going to raise it after 6k to 20psi and go again.
it's 100 bux so whatever. on the freeway it feels good it pulls very smooth because of the ramp up.

[someguy2800]

What does your timing map look like? It really falls on its face at 5800. I would have expected that turbo to spool alot faster and make a bit more than that, but if you say it doesn't pick up from 20 to 30 psi well then the evidence says its done.

[Robocop]

Untitled by jet jones, on


ya it's hard to believe it's maxing in the 400s.

i changed it from 5500 to 6800
to ramp up to 20psi see how it'll do i'll post a log.

i was also worried if there is a restriction somewhere else like my air filter or something.
but then would it make it fall so fast there.
very troubling.

Tight fit by jet jones, on Flickr

[PowerKraut]

Is the cam timed correct?

If you dont wanna switch to a bigger turbo, go pre-turbo meth and up the boost

[Robocop]

idk about cam timing i'm a noob to that stuff i just got it put in by the head rebuilder.

here's the new boost targets.
Untitled by jet jones, on Flickr

[PowerKraut]

ditch the filter for test rides. looks to be on the smaller side.

[someguy2800]

I would also like to see what it does without that filter. That can't be helping matters.

[Mklock]

Yeah, correct me if I'm wrong of course it would be somewhat hard to do what I'm about to say to your setup but, I run a 4" intake pipe with a proper matching 4" massive stovepipe K&N filter, also I think turbo intakes like straight pipe with some kind of ducting somehow to get outside engine bay air.

[Robocop]

Absolutely correct.
I had to fk up the sleeper look, but made sure it wasn't the filter. It seems to not be a filter restriction.
power feels about the same.

Bigger filter by jet jones, on Flickr
Bigger filter by jet jones, on Flickr
Bigger filter by jet jones, on Flickr
What have I done by jet jones, on Flickr

[Robocop]

So went for the 20psi and it felt the same exact sht...

Looks like it even maxed out the pump.. or injecters? idk.

felt the exact same.

graph by jet jones, on Flickr

[MrMuddle]

I could be wrong, to me that log is saying you're pretty much maxing out your injectors at 96.2%! Are you using closed loop boost control with Megasquirt? Looking at your boost target table you're telling it you only want wastegate pressure under 90% tps for any rpm. Also as your values are so close you could adjust the rpm row to give you greater control of the boost target under 5k.

Your boost duty is also quite up and down, its been a while since I've looked at CL boost control, but does the turbo spool up nicely once you're over 90% tps or is it a bit jumpy as maybe your PID settings aren't quite right so it's not spooling properly?
I'm no expert with Cl boost control and it may not affect the drop off at all, but if something is wrong with the PID settings it could help with spool up. Another option would be to switch to Open Loop where it's just duty based and see if it's any different overall?

[Robocop]

yup. waste-gate is 9psi and that's good enough for me part throttle.
anything below 5k will match the 5k target.

So in that logs it's 15psi.

it comes on soft to avoid initial spike.
The ebc starts to easy it in 3k to 3.5k.
so ya, it could boost sooner but it saves my clutch/axles/gears.

Boost duty swings is just the valve trying to target boost on/off. it's pretty crazy.
valve moving at 19hz. it's one of the older valves diy offered.


also.

Will this fix things or is it just the nature of the m30 to die after 5.8k?

https://www.ebay.com/itm/Holset-Turb...ty!92804!US!-1

[NOTORIOUS VR]

Going by this thread (M30 w/ HX40 turbo on E85), https://www.bimmerforums.com/forum/s...-M30-HX40-dyno

I think you just need to get bigger injectors and/or pump and keep raising the boost until you have a nice flat TQ curve holding to 400 like the other thread...

[someguy2800]

Your intake air temps are pretty good which would indicate to me the turbo is not choking out completely. You said you ran it up to 30 psi before, do you have any datalogs of that? A cam and springs would probably really help it pull to a higher RPM too. My initial thought looking at the drop off on your dyno graph was its probably floating the valves or something is wrong with the tune or ignition system.

[328iFun]

Is the cam timed correct?

If you dont wanna switch to a bigger turbo, go pre-turbo meth and up the boost

I have a second meth nozzle was just thinking about placing it in the turbo inlet. But wouldn't the MAF get wet?

[Def]

Turbo is pretty laggy, but honestly, I think that's what you're going to get with a big turbo on a very low VE SOHC 2V/cylinder head. Late boost response due to the big turbo and old turbo tech, then as soon as you spool it up the engine is out of breath and your VE is dropping like a rock.

You could probably put another couple degrees of timing towards redline, but it probably won't make a huge difference to your power, just add a little bit right at redline.

Looks like your WG boost control is to vent the WG line signal. You can put some duty in before you go WOT to speed up the boost response a little.

[Robocop]

thanks. i really appreciate the very helpful suggestions and will order some valve springs and upping timing
but didn't want to post back until i re-dynoed


Just a thought, Why does fuel needs keep going up when power actually plummets after 5,8k

Also, here's an old log just having re-wired the fuel pump and using a crappy mbc.
could that be some evidence of the valve float?

ok.
Shoots up to 17psi @ 3.5k
simmers down to like 15/14 and goes back up to 17psi but see that pressure drop ?
17.3psi @ 5,875k
14.3psi @ 6,195k hangs then drops rpm
17.0psi @ 5,939k

looking even closer the rpms fluctuate from 5,6 rpm to 6,2 rpm.
They goes up/down 20 to 40rpms. not including that huge spike. hm.

valve float? by jet jones, on Flickr

[PEI330Ci]

RPM fluctuation is normal....you'll see that on the street too. The higher the gear load, the more obvious it is. In lower gears the rate of change of RPM covers up the fluctuations a lot....

I've been caught out before with this with Nitrous activation, where the engine exceeded an RPM threshold deactivating nitrous, but then with the nitrous off the rpm dropped below the threshold....and this would cycle a few times making it feel like you hit the rev limiter.

RPM activated devices usually use some form of Hysteresis as a result....

[rajicase]

That turbo is done. My s256sx was done at 460whp.

[Nutzy]

My thoughts...

1 - your TQ takes a pretty massive hit at only about 4750rpm. A gradual roll-off is fine, but this is dramatic.
2 - Not being familiar with MSxx, what's with the EGO (correction?) beginning at about 4800rpm?
3 - 4800 is too low to be expecting valve float
4 - Your air filter sucks....for real. The pressure drop inside that b*tch must be crazy and turns a 60lb compressor into a good deal less and spikes turbine shaft power up as well (but you've fixed that now).
5 - Is it mildy misfiring? What are your plugs, your ignition set up, and plug gaps?
6 - Is the clutch and or tires beginning to slip? Or is it a hub dyno?
7 - Your 60lb compressor should be able to do 550whp on e85
8 - Where is the cam timing? Are you certain it is correct?
9 - What intercooler? Can you log pre and post IC pressure?

So many variables eh! Years ago I had my S13 SR20DET on the dyno to diagnose why it felt 'flat'. Under boost on the dyno, it was misfiring in a barely perceptible way - you could hardly hear it - but it knocked power out of the thing pretty badly. Maybe it was the difference between a good burn, a shitty burn, and a total misfire? So we pulled the plugs and they were coated in this reddish brown all up on the porcelain. The dyno guy - who I knew and trusted - laughed and said "Ah, you are running Shell Optimax aren't you". He'd seen lots of cars with issues lately and they all had this crap on the plugs AND were using Optimax 98 RON. A dash to the store, install new Platinums, problem solved!

valve float? by jet jones, on Flickr

[Robocop]

Thanks nutzy i appropriate your help

EGO is the 02 correction factor so it seems i was alittle richer than target
so EGO was bringing fuel down. I think the limit is like 0.5 afr.

On the turbo size it's actually a 58mm. idk if that really changes things.

Plugs are Ngk bpr7es i took 6-3 out before dyno and looks very clean.
but will check the other half maybe you're right on that. Uses the ign1a coils from diyauto in wasted spark.
https://www.diyautotune.com/product/ign-1a-race-coil/

ya, the clutch slips sometimes on the freeway so i have to kick it in to re-bed, then it's good to go.
it's a dynapack and the run was in 3rd to help the clutch and he said the dyno calibrates for the ratio
and doesn't effect power except the later spool

Cam timing. I have no idea. I had the head rebuilt and gave him the cam I assume there's just 1 way to put it in.
if you're talking about with an adjustable gear, there isn't one is that something i should get????
This is what i got.
http://www.catcams.com/products/cams...MSETUP_id=1428

For now i can't log the pre-cooler temps because i don't have a sensor/wired but i WILL get on that for you.
i think the cooler is 24x18x3 biggest cooler an e30 could fit.
Intercooler by jet jones, on Flickr


On the dyno by jet jones, on Flickr

2 - Not being familiar with MSxx, what's with the EGO (correction?) beginning at about 4800rpm?

5 - Is it mildy misfiring? What are your plugs, your ignition set up, and plug gaps?

6 - Is the clutch and or tires beginning to slip? Or is it a hub dyno?

8 - Where is the cam timing? Are you certain it is correct?

9 - What intercooler? Can you log pre and post IC pressure?

So many variables eh! Years ago I had my S13 SR20DET on the dyno to diagnose why it felt 'flat'. Under boost on the dyno, it was misfiring in a barely perceptible way - you could hardly hear it - but it knocked power out of the thing pretty badly. Maybe it was the difference between a good burn, a shitty burn, and a total misfire? So we pulled the plugs and they were coated in this reddish brown all up on the porcelain. The dyno guy - who I knew and trusted - laughed and said "Ah, you are running Shell Optimax aren't you". He'd seen lots of cars with issues lately and they all had this crap on the plugs AND were using Optimax 98 RON. A dash to the store, install new Platinums, problem solved!

[someguy2800]

The cam timing would be set when you put the timing chain on, not when installing the cam into the head, so whoever put the head back on the motor set the cam timing.

[PowerKraut]

...so whoever put the head back on the motor set the cam timing.

Yeah, i mentioned cam timing pretty early in this thread. would be the very first thing to check in my opinion, besides the obviously restrictive filter. check it already

[Robocop]

^i did and posted in this very thread
looks like about twice the size maybe

timing is correct then.
This is how to set m30 cam timing.
https://cdn2.hubspot.net/hubfs/38673...-set-tdc-2.jpg

today i'm just going to replace the dryer hose with this flex stuff and braced the boost pipes @ throttle body.
bov is on the small side so it pops off sometimes.

Bigger filter. check
cam timing. check
up timing to 22, 24 after 5.5k. check
valve springs. need
check all plugs. need

bigger turbo last resort.

Flexhose by jet jones, on Flickr
BoostHolder by jet jones, on Flickr

[JOutterbridge]

Question, what AR turbine again? I think you have the smallest compressor so it will max out around 540bhp. The turbine if oversized WILL make it lazy. And you're dropoff in torque up top could be various factors as stated above...