850 r ecu in t5?

**MoleT-5R** · Thursday 11th February 2016, 23:40

Originally Posted by Bigsi15

So found this in the Garrett site, almost perfectly describes it:
A. Boost creep is a condition of rising boost levels past what the predetermined level has been set at. Boost creep is caused by a fully opened Wastegates not being able to flow enough exhaust to bypass the housing via the Wastegates itself. For example, if your boost is set to 12psi, and you go into full boost, you will see a quick rise to 12 or 13psi, but as the rpm's increase, the boost levels also increase beyond what the boost controller or stock settings were. Boost creep is typically more pronounced at higher rpm's since there is more exhaust flow present for the Wastegates to bypass. Effective methods of avoiding or eliminating boost creep include porting the internal Wastegates opening to allow more airflow out of the turbine, or to use an external Wastegates.

Mole you may have hit it on the head there. Any ideas how to solve this, can you tighten the arm too much so it limits the opening perhaps?

Thanks again

over-tightening is not a good idea and most probably will cause your boost spikes, If we've found the issue and
I am correct in how I've heard how this next step should be done, then you should really now wind the actuator back off and then re-set the actuator to standard or desired boost level without the bcs plumped in ( boost gauge required here ), but still connected to the wiring ( else limp/mil mode will trigger ), when desired base boost level is set the bcs can be replumbed, Boost cut could possibly occur if your on a standard ecu ( then slacken the rod a half turn at a time till the problem is cured ).

**MoleT-5R** · Friday 12th February 2016, 04:57

Originally Posted by Bigsi15

So found this in the Garrett site, almost perfectly describes it:
A. Boost creep is a condition of rising boost levels past what the predetermined level has been set at. Boost creep is caused by a fully opened Wastegates not being able to flow enough exhaust to bypass the housing via the Wastegates itself. For example, if your boost is set to 12psi, and you go into full boost, you will see a quick rise to 12 or 13psi, but as the rpm's increase, the boost levels also increase beyond what the boost controller or stock settings were. Boost creep is typically more pronounced at higher rpm's since there is more exhaust flow present for the Wastegates to bypass. Effective methods of avoiding or eliminating boost creep include porting the internal Wastegates opening to allow more airflow out of the turbine, or to use an external Wastegates.

Mole you may have hit it on the head there. Any ideas how to solve this, can you tighten the arm too much so it limits the opening perhaps?

Thanks again

also after reading this post again, aren't we be really talking about wastegate creep, where as boost levels rise the wastegate creeps open earlier than it's predetermined setting thus your boost tails off before it should, this would be common for a failing/old actuator

**Bigsi15** · Friday 12th February 2016, 12:45

So I tried Lengthening the waste gate arm today just in case it was unable to push far enough to open enough, turned it about 1 1/2 turns and it's done nothing. I can only assume at this stage the ECU was perhaps not set back to standard properly as leaving everything alone as is and using my stock ECU in runs absolutely fine. I'll send it back to the chap for another go and keep you updated! Thanks for the help so far

**claymore** · Friday 12th February 2016, 13:10

You could have gained your "slight performance increase" by simply fitting a MBC, I don't know why you would bother faffing about with swapping to a 850R ecu, why not fit a HLM or Rica ecu?

**Bigsi15** · Friday 12th February 2016, 18:26

You're absolutely right, at the moment though I am looking for a stock replacement to avoid major insurance issues. The plan (very slow work in progress!) is another engine build with stronger rods and a number of supporting modes including a good tune but that is still quite a way off so this would be a stopgap and out of interest as well really

**Bigsi15** · Friday 12th February 2016, 20:07

There are obviously a lot of far more intelligent people on here than me who know a lot more about maps :-) I was wondering if I could rack your brains! I have read a lot about how too much boost too lowdown with an incorrect map can do a lot of damage to a stock engine mainly the rods, but I don't seem to be able to find any more detail on what too much boost actually is. This ECU in its current state seems to steadily build to about 0.4 bar from 2000-2500 rpm reaching about 0.8 bar by 3000 rpm which I believe is about stock target for an r, it will then however spike quite suddenly up to about 1 to 1.1 bar within 3-3.5k rpmthen drop back a bit. This is about 15 PSI isn't it which I believe is when the stock ECU will try and cut things back for safety. Is this a dangerous tune for a stock engine and turbo? Thanks guys sorry for all the questions!

**claymore** · Friday 12th February 2016, 20:43

you're not going to bend rods with a 15g, I'm using an 18T with a HLM Map and a bleed valve at 22psi, and my rods are fine, as long as you don't hit full boost under 3500rpm you will be fine

**Bigsi15** · Friday 12th February 2016, 21:43

Thanks claymore. That's a decent setup if your on stock internals

can a bad tune do any harm if a 15g isn't in itself capable of? Iv heard too sudden boost build up is bad or if not tuned right can get very hot or run lean?

**claymore** · Friday 12th February 2016, 21:57

just get a hlm, rica or shem ecu and be done with it (much safer than playing around with a 850R ecu for very little gain) you're over thinking things, Adrian has a 15G and a basic tuned ecu and is managing low 14's on the quarter mile

**claymore** · Friday 12th February 2016, 22:04

look, no bent rods.

**Bigsi15** · Friday 12th February 2016, 22:12

Yeah think your right, il just wait till the final build is done then get on to Shem or Tim and let them do the hard bit! Lol! Thanks for your help buddy

**MoleT-5R** · Saturday 13th February 2016, 00:52

Originally Posted by Bigsi15

Yeah think your right, il just wait till the final build is done then get on to Shem or Tim and let them do the hard bit! Lol! Thanks for your help buddy

Where you racing a Gul to Cosford in that clip......lol......Seriously though I run high boost on standard rods just and make use of the higher rev range so when you change up you don't drop into 3000-3500rpm danger zone, mines been boosted and hammered daily for over 9 years and going stronger and stronger ( it will go bang sometime soon , but it is a 300,000 miler with a 200,000+ engine and I drag the arse off it chasing the 13's)...

**Bigsi15** · Saturday 13th February 2016, 11:04

Haha thanks mole. What's your setup? My other worry is that the ecu has not been set up for my car so not sure on timing and air fuel ratios etc which makes me cautious!