VersaTune User Forum

Hi guys, ive currently got Skiptown cat tuning my car for me but we both cannot work out why my WGDC goes up to 100% in the higher revs. I have recently fitted a FMIC to the car which at first we had problems with boost leaks but they are all fixed now and the system has been tester upto 22PSI.

The car really appears to be struggling to make the power it does which apparently with my modifications isn't as much as it should and apparently the amount of air the MAF is registering is quite low for my car as well.

Below i've posted some logs that I did. Ive tried to upload a copy of the MAP but it won't allow me to do it for some reason im not sure of but i can e-mail it to anybody that would like to have a look at it. If any of you guys could have a look at it for me and can see what is possibly causing the problem and make the relevant adjustments to the MAP then I would very much appreciate it.

Many Thanks
David

Did you try the new tune I sent you yet?

skiptownmcat wrote:Did you try the new tune I sent you yet?

Currently running it in but should get some logs for you today

You're flowing around or more than 250g/s which is probably the limit of your K04. This turbo can flow even more than that (some managed to push up to 280g/s with it) but it also depends on how worn your turbo is. the Boost air temperatures are also important, the hotter the air the higher the volume, so the turbo simply can't push into the engine as much as you want.
Moreover, FMIC and less than 350-400bhp = non-sense (it starts making sense around 350-360bhp, meaning 330-340g/s on pump gas). You should have gotten a better TMIC, that's all, because now your turbo works harder now to build that boost and meet the load targets.

P.S.: try logging more useful things such as the BAT instead of both APP and relative throttle position. App=100 means tp_r is around or above 74 (usually 76.something if you're not hitting any absolute limit), so you can drop APP from your logs. Same for mass airflow and MAF voltage - you need these logged both at the same time only when you're doing your MAF cal and yours seems to be perfect. Add ignition timing instead of MAF voltage.

I had just redone his maf cal after fixing 3 boost leaks, that's why it's there.

mituc wrote:You're flowing around or more than 250g/s which is probably the limit of your K04. This turbo can flow even more than that (some managed to push up to 280g/s with it) but it also depends on how worn your turbo is. the Boost air temperatures are also important, the hotter the air the higher the volume, so the turbo simply can't push into the engine as much as you want.
Moreover, FMIC and less than 350-400bhp = non-sense (it starts making sense around 350-360bhp, meaning 330-340g/s on pump gas). You should have gotten a better TMIC, that's all, because now your turbo works harder now to build that boost and meet the load targets.

P.S.: try logging more useful things such as the BAT instead of both APP and relative throttle position. App=100 means tp_r is around or above 74 (usually 76.something if you're not hitting any absolute limit), so you can drop APP from your logs. Same for mass airflow and MAF voltage - you need these logged both at the same time only when you're doing your MAF cal and yours seems to be perfect. Add ignition timing instead of MAF voltage.

The main reason i went for a FMIC is because i prefer the ook of it but i do intend to get a Downpipe and some other supporting modifications to get to about 360bhp.

So you think that im at the limit of my turbo with the FMIC now?

360bhp with what turbo? I'm asking this because with the stock K04 you may kiss the 300's (on pump gas) but you can't really go much higher than that. Also, for 360bhp you will have to be very carefull with the tune because you're going to approach the limit where the stock rods may snap.

The FMIC gives you insignificantly lower BAT's during hard acceleration and cruising compared to a TMIC with a good core but it hurts your spool a bit and it's also in the way of the air going to the engine radiator. So you will get BAT's with like 5-6C lower than with a TMIC and about as much higher ECT's. Also, the turbo is cooling up with engine coolant and oil (cooled down by the engine coolant as well), and if you're going to push this K04 a bit farther you will really need that heat to dissipate as quickly as possible from the turbo and engine.

So no, the FMIC you have is not limiting your top end flow, just the initial spool up maybe and hurts the engine cooling a bit. As I said previously 255g/s is a pretty good number for the K04 and the numbers significantly higher than that (270-280g/s on pump gas with no E85) are very rare and fortunate exceptions.
Adding a downpipe with a sport cat (doesn't really make sense to go de-cat) will help the initial spool quite a bit and may also give you some more top end flow if the turbo you have will be able to spin a bit quicker (don't forget it has a shaft, not bearings, which means it can't spool that fast without overheating). However, at this point we can't really tell why your car is struggling to make power as I've seen 255g/s of air there which should be goot for like 270bhp (real wheel bhp, not some dyno shop crappy estimation). If you'd be able to log the BAT's and timing it will be clear what the difference between your timing targets and real timing is and eventually conclude if the difference (if any significant) is a result of high BAT's or something else.

A fully bolted K04 w/ catless 3" TBE will hit 300 g/s in cold weather at sea level. That's pretty much the best case scenario.

Yeah, at altitude I barely see 240 g/s from a fully bolted setup. Its sad really

He means 360bhp at the crank mituc, maybe possible bolted with meth.
I'm in the process of backing off the higher end loads with him to get that 100% down, And there's still a lot left on the table with ignition timing.