Hybrid K04 Turbo Discussion

wild willy

Full Member
Aug 4, 2003
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WW - 218g/s on your log above.. what size maf housing?
Its one of these Bill.
http://www.modshack.info/bamm.htm
I run APR stage 2 program which only runs on 3 bar reg. Once the hybrid was fitted and tweaked i started hitting fuel cut at about 290bhp (approx 228g/sec on orig maff tube)and fault codes indicating Maff signal too high.
The 4 bar reg and oversized maff cured both problems, although without the mbc fitted, during the spike i still get Maff signal too high codes logged.
I'll measure the actual diameter of the Maff tube latter.
 
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wild willy

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Aug 4, 2003
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A standard LCR Maff has an internal diameter of 70mm which equates to a csa of 15394mm squared.
The uprated maff housing i'm using has an internal diameter of 74mm which equates to a CSA of 17203mm squared. An increase of 11.75%.
 

wild willy

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Aug 4, 2003
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I managed to break the 300bhp barrier today. On a Dastek Dyno i got 308.3bhp and 292.4ft/lbs torque. This was 1.3bar @ red line. Plenty left in the tubby for more bhp but thats enough for now, it held torque well throughout the rev range. High flow mani in the new year, so we'll finally see what these hybrids can do.
 

wild willy

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Aug 4, 2003
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thanks Willie, no wmi yet thats just the k04, induction kit, zorst, fmic and stage2 APR.
MWI and mani nextyear which should take it to 340bhp.:headhurt:
 

Feel

Veedubya 'velle
Jun 12, 2003
4,918
2
Midlands
I managed to break the 300bhp barrier today. On a Dastek Dyno i got 308.3bhp and 292.4ft/lbs torque. This was 1.3bar @ red line. Plenty left in the tubby for more bhp but thats enough for now, it held torque well throughout the rev range. High flow mani in the new year, so we'll finally see what these hybrids can do.

:clap:
 

Feel

Veedubya 'velle
Jun 12, 2003
4,918
2
Midlands
It's taken some time to get there, was it just the fuelling? I see your Stage 3 APR Post, I think that's the way to go, if not, see what Bill will do (if he's not too nervous to push an unknow tubby).

If it's anything like Sie's was, I bet it drives really nice.
 

wild willy

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Thanks mate. :) how credible would you say Dasteks rollers are in general. The level of tune i ran on the dyno was quite soft as i'm a bit concerned of my stock rods but i was still measuring 240 g/sec in a stock maff housing unmolested (not descreened) athough i ran an oversized maff housing on the day.
 

Damoegan

Sir Bob,a geordy legend..
Oct 15, 2007
8,993
3
Newcastle
From my experiences with Dastek rollers they seam very accurate, Carl.

We have had a few RR days up this way on them and they have always produced spot on numbers for standard cars and expected numbers for tuned cars.
 

wild willy

Full Member
Aug 4, 2003
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Wales
It's taken some time to get there, was it just the fuelling? I see your Stage 3 APR Post, I think that's the way to go, if not, see what Bill will do (if he's not too nervous to push an unknow tubby).

If it's anything like Sie's was, I bet it drives really nice.
Rome wasn't built in a day ;) but i do need to speed up my modding process if i'm to finish the car before the world runs out of petrol. :D
My current APR map is perfect in nearly all ways, fueling is excellent with a 4 bar reg (not exceeding 90% injector duty cycle) and a few tweaks with lemiwinks ( main fueling reduced by 11%), 0.83 lamda under WOT.
I have two issues with boost control however. To increase boost using V tune i increase the boost request by 10% say, which increase requested boost at the red line to 1.45 bar but it does so linerly across the rev range which causes requested boost mid rev range to exceed 2550 mb. This is pants because my map sensor will only ever reach 2540mb and so the map never reaches its requested boost values and so boosts uncontrolled until the boost rquested by the map drops below 2540mb, i overcome this with a mbc connected in parallel with the n75 valve but its not ideal.
The second boost issue i have is n75 duty cycle and actuator spring pressure related.
Because the hybrid is compressor heavy compared to a stock tubby, the 6 psi actuator doesn't even produce stock tubby performance levels, so i upgraded to a forge uprated actuator with a 10psi (measured) spring tension. This is great and produces the goods but does occasionally cause overboost/limp issues in 5th gear on rolling roads etc and is very annoying. Its that 200mb difference between requested and achieved that cause the ecu to throw a limp mode which most stage 2 software still keeps but appears to be missing in most stage 3 codes.