VEMS tune opinions

[vwnut8392]

after 3 months of sitting because i havnt had time to touch my project car i finally had time to install the HX35 i've had sitting for it and i picked up a set of bosch EV14 1000cc injectors. it was time to work on reconfiguring everything and im still working on it but it seems to run fairly well so far although its pretty rich still. and needs some work but i figured i'd ask for some opinions and tips from the pro's on here to help me progress getting it running right a little faster. i've attached the last vemscfg file i ran and the last log file.

list of what all is done to the engine and related so far.
-AAN from 93 S4
-ebay tubular turbo manifold
-stock wastegate with 2.2 bar spring
-holset HX35W
-3in turbo back exhaust with no cat or muffler and gate is dumped externally
-front mount intercooler
-7A cams
-bosch EV14 1000cc injectors
-bosch 044 fuel pump
-07K coils
-NGK BKR7EIX plugs gapped to .024
-victor reinz metal head gasket
-ARP head stud kit

all the pulls are done on a private strip of concrete where a warehouse once stood on the property at my garage so no dyno time. please be nice as im still trying to get the hang of using vems and all of its parameters.

[yada-yada-yada]

no expert here, but have a similar setup.

looks good, good idea on pulling fuel, im curious about your ign. timing at idle though.

AANw/metal headgasket,
arp headstuds,
630cc inj.
holset hx35 hybrid with k26 hotside,
1.8T ign coils,
STR exhaust log manifold,
7a cams,
stock intercooler,
stock exhaust w/straight pipe after middle muffler.

[vwnut8392]

no expert here, but have a similar setup.

looks good, good idea on pulling fuel, im curious about your ign. timing at idle though.

AANw/metal headgasket,
arp headstuds,
630cc inj.
holset hx35 hybrid with k26 hotside,
1.8T ign coils,
STR exhaust log manifold,
7a cams,
stock intercooler,
stock exhaust w/straight pipe after middle muffler.

i dont use an ISV, i use the corner of my ignition table, the throttle stop on the throttle body and spark cut idle control to keep the idle under wraps. ISV went bad on my daily S6 avant and the one on my 4000 was brand new so i put it on the S6 and thats pretty much that. i've done a few more adjustments since i posted this too, it was a bit rich for my liking still. im trying to get the AFR's stable around 11.7 and 12.2 under full boost but im not at the boost levels i want to be at yet either. im at 18psi now and the goal is at least 25psi and if the AFR's along with injector duty cycle looks good im going to keep turning the boost up. i have an HX40 sitting on my shelf too thats ready to go on when needed

[chaloux]

I had no idle control and a very basic intake path on the 4000. It had a rock solid idle.

[88a5tq]

I had no idle control and a very basic intake path on the 4000. It had a rock solid idle.

Were you having to give more gas on cold start to keep from stalling? Took me 2 1/2 to get mine right as I've posted before. When it was unplugged I couldn't keep the car running without giving pedal when cold. It always would run fine after a minute.

[vwnut8392]

i have to give mine a little throttle to start cold but once it starts it idles at a 1000rpm cold and settles down to around 800rpm when warm.

[88a5tq]

Yep, that sound identical to how mine behaved without the IAC. I see no mention of rods. I don't suggest I know much about turbos but you must seem comfortable running that holset at 25 psi on the stock bottom end. Probably right near the limit right?

yada-yada-yada, how well does that hybrid hold pressure above 5k rpm? I'm curious how it compares to mine. K26 hotside gets me a little choked up up top

[vwnut8392]

Yep, that sound identical to how mine behaved without the IAC. I see no mention of rods. I don't suggest I know much about turbos but you must seem comfortable running that holset at 25 psi on the stock bottom end. Probably right near the limit right?

yada-yada-yada, how well does that hybrid hold pressure above 5k rpm? I'm curious how it compares to mine. K26 hotside gets me a little choked up up top

im not scared of the stock rods, they are plenty strong in my opinion. to me its all in how its tuned is how far you can stretch the stock rods and pistons. i read a real in depth thread on S2 forum about stock rods and how much they can really hold and what was said was the onset of torque too fast too soon is what kills them so i figured the lazy holset should help combat the onset of torque too quickly and its all in tuning after that.

my turbo isnt a hybrid, its a straight drop off from a 98 dodge/cummins truck. im revving to 7500 and it still feels like the turbo and the engine wants to keep going and make more power as it sits. i thought about a K26 housing but i had a feeling about it being choked off at high RPM so i just stuck with the stock twin scroll holset housing because i see the cummins guys just unhooking the stock gate and pushing them to 48psi and their making power up that high somehow. i was also using the DSM guys for reference on the turbo because those guys love holset and make good power on them.

[88a5tq]

Damn that's crazy pressure! The hybrid turbo part was for the guy with the screen name yada-yada-yada but still interesting. Link to s2forum thread? Thanks

[vwnut8392]

Damn that's crazy pressure! The hybrid turbo part was for the guy with the screen name yada-yada-yada but still interesting. Link to s2forum thread? Thanks

i have the stock holset documentation for the HX35 and HX40. it says that when setting base boost pressure on the HX35 in a dodge truck is 26psi and they also say that the maximum pressure output safely is 42psi if i recall correctly. the HX40 is like base pressure at 34psi and max 56psi. now i would assume this is all based on the engines these turbo's actually belong to as well.

Actually here's the data for my turbo straight from the holset catalog.