[Mk2] [Turbo] Limits of the stock fueling system

[2mad]

Ryanrs made over 400hp on 540s,
Granted was a 2.2ltr I believe.

Wow, 400hp on 540's that is amazing

[jimGTS]

Likely a big pump or 2 and raised fuel pressure at a guess also.
Was his 'running in' map, ha.
Then went to 550hp+! (Obviously not on 540s).

I'd have thought raised fuel pressure with 540s can get closer to 360-370 range on a 2ltr surely?

[Ryan S]

I don't fancy running stock fuelling for too long as IDC was at 97% for 1.2bar!

JD, You seem to be the exception to prove the rule, for how long did you run 97% injector duty cycle @1.2bar and your car not go bang

You must have the record for power vs stock fueling with rev3 injectors

this ^^

can't help thinking everyone has been upgrading injectors/ecu for no good reason, especially if you're only aiming for the 350bhp area

[tubby_tony]

JD, You seem to be the exception to prove the rule, for how long did you run 97% injector duty cycle @1.2bar and your car not go bang

I have been running 97% @ 1.3 bar on a CT20b for approx 9 years now. Granted I dont floor her every where but she has a few rolling roads and a good few spirited early morning drives over the weekends of ownership. Mind you, she is probably overly serviced and pampered to keep her in great running condition.

[Marf]

All the pampering and servicing in the world won't help you if you run the engine lean. I'd say you've been pretty lucky

[Ryan S]

JD, You seem to be the exception to prove the rule, for how long did you run 97% injector duty cycle @1.2bar and your car not go bang

I have been running 97% @ 1.3 bar on a CT20b for approx 9 years now. Granted I dont floor her every where but she has a few rolling roads and a good few spirited early morning drives over the weekends of ownership. Mind you, she is probably overly serviced and pampered to keep her in great running condition.

you got any figures?? I can't believe all this info is just cropping up now

[raptor95GTS]

Paul Port was running something like 22psi on the CT20b on his rev3, damned thing runs so rich at the top end it can run the boost no problem. Mind you, he was a clever sort and had made the clamping Fuel Cut Defender, used the stock VSV to set the boost level he wanted and ran Water Injection

[Ryan S]

All the pampering and servicing in the world won't help you if you run the engine lean. I'd say you've been pretty lucky

9 years worth of luck?? I doubt that

[Marf]

97% max duty doesnt leave alot of overhead for overboost, boost on a cold day etc etc

I'd not be comfortable running my car at the limit like that....

Granted I dont floor her every where

I like to be able to use my car like its got an OEM map, i.e. can take whatever I throw at it in whatever weather conditions. Frankly I'm surprised the tuner left it like that

I'll sticky by my original opinion. Lucky.

[Ryan S]

97% max duty doesnt leave alot of overhead for overboost, boost on a cold day etc etc

I'd not be comfortable running my car at the limit like that....

Granted I dont floor her every where

I like to be able to use my car like its got an OEM map, i.e. can take whatever I throw at it in whatever weather conditions. Frankly I'm surprised the tuner left it like that

I'll sticky by my original opinion. Lucky.

guess it depends on the boost control, admittedly I wouldn't be too keen on running my car on the ragged edge either, my boost controller does spike a wee bit

[jimGTS]

Rev1/2s run 100% duty soon as it hits fuel cut boost levels (ie 12psi).
1000s of people over the years have run there cars over this boost level without 'fueling problems', or 'running lean'.
Why would it be an issue with 540s on a gen3?

9years is a plentiful example that high duties isn't a problem.
I have plans for a bit more power without the hassles/money and worries of injector and ecu upgrades.
I've been there, done that, the gen3 ecu is capable of a lot more than people give it credit for.

[Ryan S]

Rev1/2s run 100% duty soon as it hits fuel cut boost levels (ie 12psi).
1000s of people over the years have run there cars over this boost level without 'fueling problems', or 'running lean'.
Why would it be an issue with 540s on a gen3?

9years is a plentiful example that high duties isn't a problem.
I have plans for a bit more power without the hassles/money and worries of injector and ecu upgrades.
I've been there, done that, the gen3 ecu is capable of a lot more than people give it credit for.

I ran 14PSI on my rev2 the whole 5 years I owned it, the current owner runs a CT27 (hybrid) and as far as I know the engine is still going strong

[Marf]

Rev1/2s run 100% duty soon as it hits fuel cut boost levels (ie 12psi).

That's a safety feature. I can bet you anything you like that at 11psi the duty is nowhere near 100%

Any tuner who'd leave a customers car with a fuel map that nearly maxes out the fuel injectors is a tuner worth avoiding.

[Marf]

9years is a plentiful example that high duties isn't a problem.

Nah it's just evidence that the owner has been lucky in this singular instance not to create a situation where the airflow through the engine has exceeded the ability of the fuel system to provide for it

[2mad]

sheppy and jimGTS are spot on , I ran my rev2 engine at 1bar and 1.1 bar for 6 years with a ct20b and I could easily have pushed it further, after 4500 rpm (full boost) iirr afr's pretty much went to 10:1
I spent days with a mines ecu so it had fuel maps for higher boost (still 10:1 afr on boost) trimming fuel with a afc and 1:1 fpr to bring it down to 11.5 then 50/50 water/meth on top gave me 10.8 afr and the car went like stink.
I was happy to stick with the 440's my wideband gauge never did anything out of the ordinary to show the 440's couldn't keep up .

After my experience with tuning a rev2 I will be pushing my st205 to around 325/330 i dont want to be greedy

Kev.

[Ryan S]

sheppy and jimGTS are spot on , I ran my rev2 engine at 1bar and 1.1 bar for 6 years with a ct20b and I could easily have pushed it further, after 4500 rpm (full boost) iirr afr's pretty much went to 10:1
I spent days with a mines ecu so it had fuel maps for higher boost (still 10:1 afr on boost) trimming fuel with a afc and 1:1 fpr to bring it down to 11.5 then 50/50 water/meth on top gave me 10.8 afr and the car went like stink.
I was happy to stick with the 440's my wideband gauge never did anything out of the ordinary to show the 440's couldn't keep up .

After my experience with tuning a rev2 I will be pushing my st205 to around 325/330 i dont want to be greedy

Kev.

have to agree, i don't think anyone to date (other than the 345bhp car mentioned) has pushed the rev2 or rev3 tubbys anywhere near their limits yet, look at turbonozs budget build? 487bhp i believe? on 440s albeit he blew his ringlands to smithereens eventually.

[jimGTS]

That's a safety feature. I can bet you anything you like that at 11psi the duty is nowhere near 100%

yep, im not denying that. simply saying most are running way more than that and dont have problems.

Nah it's just evidence that the owner has been lucky in this singular instance not to create a situation where the airflow through the engine has exceeded the ability of the fuel system to provide for it

in your opinion.

[Marf]

9years is a plentiful example that high duties isn't a problem.

In your opinion, and anyway, one example is not plentiful especially as the guy says he doesn't push his car.

97% duty is bodgetastic mapping

We'll have to agree to differ.

[JD]

I've opened a can of worms... or is that snails!

[2mad]

I've opened a can of worms... or is that snails!

I dont think you have opened a can of worms, I think you have just shown (good idea on paper or not) what's possible with 540cc injectors