Power, where is the sweet spot for the road?
06-21-2023, 07:45 AM
#46
Drifting
Thread Starter
That turbo is a real Triggers broom. And you have to wonder what someone was thinking, to sink even half of that money in to it. I seem to recall it being for sale 2 or 3 times, but 170k is the kiss of death for buyers, unless it's a very special car.
06-21-2023, 07:55 AM
#47
Drifting
Thread Starter
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Eldavo (06-21-2023)
06-21-2023, 08:25 AM
#48
06-21-2023, 08:55 AM
#49
Drifting
Thread Starter
I'd like to try the autotune to start with, how close did you get with that? I'll wait until I've fitted the big turbo and binned the gutted AFM, plus fitted the boost solenoid and wasted spark, before getting it mapped I think.
06-21-2023, 10:06 AM
#50
Oh dear , I have 184,000 on my odometer !
But it is a bit special just like my mum said about me .
I'll put the 16v head to one side till you have had a go in Davids car Blade .
But it is a bit special just like my mum said about me .
I'll put the 16v head to one side till you have had a go in Davids car Blade .
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Eldavo (06-21-2023)
06-21-2023, 12:24 PM
#51
Drifting
Thread Starter
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Eldavo (06-21-2023)
06-21-2023, 02:35 PM
#52
Comes with cam cover , variocam and both cams . I will include 16 exhaust manifold and a turbo one you can cut flanges of to mate to your crossover . David has a great welder to do intake , my welder has retired .
As for valve guides , any 944 engine with the head of is worth doing the guides as they dont last long . I think its around £150 as most places dont remove , replace and ream porsche guides but use there own .
See what you make of Davids first , i think you will like .
As for valve guides , any 944 engine with the head of is worth doing the guides as they dont last long . I think its around £150 as most places dont remove , replace and ream porsche guides but use there own .
See what you make of Davids first , i think you will like .
06-21-2023, 05:12 PM
#54
Autotune was ok for getting the fuelling in the right ballpark but it doesn’t do spark advance and that is VERY conservative for obvious reasons.
06-21-2023, 06:36 PM
#55
Drifting
Thread Starter
06-22-2023, 01:24 AM
#57
Three Wheelin'
The entire exhaust back pressure discussion is an important one in terms of optimising these engines for whatever use scenario you are targeting.
The other area where I think we could perhaps look at things a little differently is not to talk about boost pressure- which is nothing more than a measure of restriction - an important practical limitation though it is.
I think we should be talking about an engine's VE in terms of the air mass it can flow in lb/min.
You can apply a rule of thumb to convert that air flow to crank bhp - approximately 10 crank hp per lb/min airflow.
Two engines with different VE's will flow different amounts of air at any given boost pressure - and as an engine is essentially a pump - we need to be thinking of the engine system in terms of pumping efficiencies rather than pumping restrictions.
Basically no two tuned 951 engines are the same - we all have various combinations of parts, whether they be factory, aftermarket or own build - so we all have slightly different "systems" - so let's look at the air flow mass of our systems to identify which are being most efficient before they encounter unacceptable levels of restriction.
That said, we tailor our build to our intended use - so some might choose to sacrifice top-end efficiency for enhanced low-end or mid-range transient response - all valid - it's horses for courses.
The other area where I think we could perhaps look at things a little differently is not to talk about boost pressure- which is nothing more than a measure of restriction - an important practical limitation though it is.
I think we should be talking about an engine's VE in terms of the air mass it can flow in lb/min.
You can apply a rule of thumb to convert that air flow to crank bhp - approximately 10 crank hp per lb/min airflow.
Two engines with different VE's will flow different amounts of air at any given boost pressure - and as an engine is essentially a pump - we need to be thinking of the engine system in terms of pumping efficiencies rather than pumping restrictions.
Basically no two tuned 951 engines are the same - we all have various combinations of parts, whether they be factory, aftermarket or own build - so we all have slightly different "systems" - so let's look at the air flow mass of our systems to identify which are being most efficient before they encounter unacceptable levels of restriction.
That said, we tailor our build to our intended use - so some might choose to sacrifice top-end efficiency for enhanced low-end or mid-range transient response - all valid - it's horses for courses.
For those keeping stock-ish engines, however, the "old school" discussion method of boost pressure numbers and the pros and cons of the limited amount of bolt-on turbo options are still valid, as this type of build is clearly geared towards someone on a budget and/or wants to keep the car close to stock parameters, and datalogging is limited. That said, I do remember some of the folks running MAF setups comparing peak raw voltages back in the day---though that is subject to the parameters of the various 951 MAF setups at the time.
To your point about measuring overall air mass, Banks Power (does mostly diesel tuning) here in the USA has the same idea, but takes it a step further:
https://official.bankspower.com/density/
Last edited by Droops83; 06-22-2023 at 01:35 AM.
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Noahs944 (06-25-2023)
06-22-2023, 02:47 AM
#58
Drifting
Thread Starter
.
06-22-2023, 06:17 AM
#59
It made 308bop on the LR/Promax chips. The 180 was on VEMS with the bobby basic map. Just ping me your email and I’ll send you the map I used - but the caveat is it was done for my engine, with my hybrid turbo, 80lb injectors, bigger valves and a different cam so as they say in the USA - YMMV!
