Hybrid K04 Turbo Discussion

[YerMother]

I also don't understand why JBS with CC couldn't remove the spiking with the remapping.

The k04 is still a fairly small turbo you have to remember and spools very fast, hence has spikey characteristics, and when requesting alot of boost quickly (ie wastegate fully closed) the overshoot is unavoidable

I suppose you could request less on inital throttle depression but it could delay spool up time. TBH i'm not even sure if you can write conditions into the software can you? Thats why you have things like the APEX boost controller thingy!

 

[Mitchy]

Mitchy's custom map looks remarkably like a standard k04 boost profile, with no extra boost requested at the top end. May be e mail was down

Yes your right, its boosting stronger in the middle and perhaps upto about 5500rpm but then after that its dead and buried. (similar to standard k04)

Although saying that i am still seeing 220-225g/s airflow readings in temps less than 5c.

About 210ish on standard K04 at same OAT.

My mapping is not at 100%, it was backed off 5 degrees for 25bhp nitrous use and i think 8 degrees for 50bhp use. I need the CC software working to adjust the map off of nitrous. (i cant get cable working with software at moment)

When i tweak the map to as it should be (disregarding nitrous) ill log again

 

[wild willy]

Yes mate the boost gauge at the mo reads 1.25 BAR @ 6,500 - 7,000 rpm in 4th, obviously holds it alittle better in fifth.

Nice figures, I'll very happy if i can get the same.

 

[wild willy]

Yes your right, its boosting stronger in the middle and perhaps upto about 5500rpm but then after that its dead and buried. (similar to standard k04)

Although saying that i am still seeing 220-225g/s airflow readings in temps less than 5c.

About 210ish on standard K04 at same OAT.

My mapping is not at 100%, it was backed off 5 degrees for 25bhp nitrous use and i think 8 degrees for 50bhp use. I need the CC software working to adjust the map off of nitrous. (i cant get cable working with software at moment)

When i tweak the map to as it should be (disregarding nitrous) ill log again

I'm sure with the right tweaks, the beast will be unleashed.

 

[Mitchy]

Thats only what gauge is saying though, who's to say gauge is reading accurately to that of vagcom? Ive yet to see any logs of Sie's yet for comparisons.

Scotty's aint boosting that well either on vagcom logs. We need some logs from you Carl aswell to all compare

 

[bentaw]

any of you guys heard of these, they make a hybrid K04 for the leon that produces between 290 and 300bhp for £800

http://www.aet-turbos.co.uk/

 

[Feel]

Thats only what gauge is saying though, who's to say gauge is reading accurately to that of vagcom? Ive yet to see any logs of Sie's yet for comparisons.

Scotty's aint boosting that well either on vagcom logs. We need some logs from you Carl aswell to all compare

We did some logging on Sie's after he had it fitted, but we've both lost then and it was certainly better than a stocker, but I can remember specific figures. He's been nagging me to do some more for you, but I've been ignoring him Derby meet next week, so we should be able to do some then.

I think Sie still has a boost controller on his, which should help with the spike and the taper.

I have to say, Wilko sounds right, yours does look very similar to a stock k04 map. Didn't want to say anything before, for fear of "setting you off". I'm not that familiar with CC - did you pay for a full custom remap?

Scotty's "only" running boost 7, which is practically stock Revo boost (Stage 1, not that familar with stage 2 logs) so I still don't understand why his requests less boost than mine If I were him though, I'd be turning up da boost and logging it.

 

[Mitchy]

I was actually thinking about taking mine off and putting the standard unit back in and sending this hybrid back to Jacob. I have been pissed off with it since fitment in December.
I cant however as my standard k04 units wastegate port had 2 large cracks in it that was discovered when it was removed. I did manage to flog it and recoup £300 back so i guess that paid for the fitment, but im still down £950 The only bonus being i now have a new turbo with 2000miles and a turbo that flows a little more 220-225g/s compared to 210g/s.

It cant be the mapping as both Jabba and CC have mapped this turbo for me and both are near exactly the same.

It does feel better upto around 5000-5500rpm but then after that it really is dissapointing.

I cant see Scotty's/Carl's turbos being any better tbh. Scotty's logs even on revo sps settings are still k04 comparable. His actual is always below his requested.

I still have a few tricks up my sleeve, turbo may well be coming off and refunded and then fitted with JBS's 05 hybrid. James said its good for 300-310bhp on his rollers which i think is excellent as JBS's rollers are as tight as a nuns

God knows why i never contacted them before this American shi**y thing was sent to me.

Polish/porting is the biggest waste of time on this turbo, it just spools very quickly and spikes high.
The thermal coating is a lot of rubbish and not proven to work as was described. Jabbasport said it had no benefits at all
Not only is the turbo rubbish the options were aswell

Feel....Can you remember you linked us to the TT that had this turbo fitted and that too was not boosting as it should have done. It had very poor rolling road results, only showing a very slight increase over the rest of the K04's.

I wish i had taken notice

Well it looks like mine and Scotty's are the same, Carl's not fitted his yet and its only Sie's that has got these figures APR and awesome

Oh well, **** happens i suppose Its only a grand down the swanny

Thank fu*k i still have the gas installed

 

[wild willy]

Thats only what gauge is saying though, who's to say gauge is reading accurately to that of vagcom? Ive yet to see any logs of Sie's yet for comparisons.

Scotty's aint boosting that well either on vagcom logs. We need some logs from you Carl aswell to all compare

2240 103.8 1760 1330
2360 128.6 2130 1570
2480 155.6 2290 1870
2640 188 2370 2270
2840 191.7 2370 2540
3040 191.7 2380 2540
3280 191.7 2400 2530
3440 191.7 2420 2470
3680 191.7 2430 2450
3840 191.7 2430 2450
4040 191.7 2430 2450
4240 191.7 2410 2420
4400 191.7 2400 2400
4600 191.7 2370 2330
4760 191.7 2320 2350
4920 191.7 2300 2280
5080 191 2270 2280
5240 189.5 2250 2250
5360 191.7 2230 2220
5520 190.2 2200 2190
5680 179.7 2170 2190
5800 182.7 2150 2140
5920 179.7 2120 2130
6040 175.2 2100 2110
6160 171.4 2090 2140
6240 162.4 2080 2110
6360 163.9 2070 2120
6480 166.9 2060 2050
6560 159.4 1000 1990

Hot off the press.
Stage 2 APR, I dialled in 105% boost but I'm not sure it registered it so it may be stage 2 standard. 4th gear pull.
Edit .... It can't be 105%boost as the requested is too low.

 

[Mitchy]

2240 103.8 1760 1330
2360 128.6 2130 1570
2480 155.6 2290 1870
2640 188 2370 2270
2840 191.7 2370 2540
3040 191.7 2380 2540
3280 191.7 2400 2530
3440 191.7 2420 2470
3680 191.7 2430 2450
3840 191.7 2430 2450
4040 191.7 2430 2450
4240 191.7 2410 2420
4400 191.7 2400 2400
4600 191.7 2370 2330
4760 191.7 2320 2350
4920 191.7 2300 2280
5080 191 2270 2280
5240 189.5 2250 2250
5360 191.7 2230 2220
5520 190.2 2200 2190
5680 179.7 2170 2190
5800 182.7 2150 2140
5920 179.7 2120 2130
6040 175.2 2100 2110
6160 171.4 2090 2140
6240 162.4 2080 2110
6360 163.9 2070 2120
6480 166.9 2060 2050
6560 159.4 1000 1990

Hot off the press.
Stage 2 APR, I dialled in 105% boost but I'm not sure it registered it so it may be stage 2 standard. 4th gear pull.
Edit .... It can't be 105%boost as the requested is too low.

Are these standard K04 turbo logs Carl? When you fitting turbo?

Just for comparison to mine....
4040 2460 2440 = 1.44bar
4480 2450 2480 = 1.48bar
4880 2380 2360 = 1.36bar
5240 2340 2310 = 1.31bar
5600 2270 2240 = 1.24bar
5920 2150 2220 = 1.22bar
6240 2080 2120 = 1.12bar
6480 1970 2170 = 1.17bar
6720 1900 2060 = 1.06bar

3400....2410/2510 = 1.51bar
3840....2430/2540 = 1.54bar (Actual 26psi or 1.8bar)
4280....2420/2540 = 1.54bar (Actual 24psi or 1.65bar)
4680....2370/2440 = 1.44bar

Mine is ahead of yours near enough all the way so there is an improvement, its just not enough. Although like i said before compressor wheel is larger meaning a larger amount of air for given pressure so do they need to boost as much to get the same output?

Given this with 8degrees timing pulled for nitrous use, im sure its got a bit more to give.

What were your MAF logs like Carl?

 

[Mitchy]

I did a bit of testing tonight with smoothed airbox vs BMC.

I thought BMC was choking things up so i fitted the smoothed airbox with green panel filter and 3'' feed hoping it would do better....

Max airflow from 5 full throttle 4th gear runs today with the BMC was 219g/s. OAT was 7.5c
Max airflow from 5 full throttle runs with smoothed airbox/panel filter was 214g/s. OAT was 4.5c

Needless to say, the BMC will be going back in tomorrow. Even with a colder OAT the smoothed airbox/green panel still flowed 5g/s less.

Max ive seen with the BMC has been 225g/s when OAT was -2c last week.

MAF readings IMO should only be logged with OAT, as its silly comparing results obtained from -2c temperatures to that of 12c temperatures.

So all of you cheaposkates who have smoothed boxes and panel filters, get a proper IK

 

[wild willy]

Standard K04 turbo still.
I'll post maff logs tomorrow.
Your logs look good mitchy they exceed all the requested, the turbo doesn't look like its been tested fully.

 

[Wilko]

Although like i said before compressor wheel is larger meaning a larger amount of air for given pressure so do they need to boost as much to get the same output?

QUOTE]

This is one of the biggest myths out there. The mass of air that passes into the engine is a function of boost and temperature. If the boost is the same, and the temp is the same, the flow is the same.
If the compressor is running slightly higher on its efficiency curve, the inlet temp may be a degree or 2 different, making minimal differences to air mass flow.

The only increase in power you will get with a larger turbo running the same boost is in the pumping losses, exhaust (turbine) side. A more efficient turbine will give some power increase, but I was under the impression that the turbine is the same in both turbos.

The only way you'll make more power is to make more boost.

And mitchy. I wouldn't necessarily take any notice of CC airfow readings. Some of the results I've seen for measured airflow vs boost on their code bears no resemblance to reality. Saying that your flows are possible, it's just they're right on 100% VE.

 

[ibizacupra]

you cannot ignore massflow rate. same boost level from larger compressor is more airflow (so long as everything else can flow it)

depends on whats the choke in the system.... exhaust turbine as John says is most likely.

bigger turbo's, compare their 1.5bar boost power levels. K03, K03s, VF34, GT28, GT30................. they are rising in proportion to their sizes. (same boost more mass airflow - bigger units sustain their boost in the rev range hence more bhp which is function on rpm and torque)

 

[wild willy]

Bill, why do you think CC has set Mitchys boost levels so low at the red line considering its an uprated hybrid. It has no problem hitting its requested.

 

[bentaw]

perhaps its cos its an unknwn hybrid and until they see more of it they dont know what it can do so they are playing it safe

 

[Mitchy]

Carl, when it was mapped by jabba the requested was quite a bit higher than the actual and the turbo couldn't make it.

They were requesting 1.4bar at 6500rpm, turbo was no where near it.

Jabba's map with the boost controller fools the deviation into not going into limp mode. Without the boost controller, if the deviation is too high the engine will go into limp mode.

With jabbas map, it was always 1 step ahead of you because of this. You could fiddle with the car, make more boost pressure and not need to adjust the requested values. On CC software you cant do this because of deviation limits set.

I need a cable that can connect to CC software so i can fiddle with a few things. My serial port cable is not working with the software, works fine with vagcom though

 

[YerMother]

Mitchy i just realised you went for CC stage 2! I thought you went stage 3!

So the reason it looks similar to k04 software is because it is. They just tweek it abit probably!

 

[Wilko]

you cannot ignore massflow rate. same boost level from larger compressor is more airflow (so long as everything else can flow it)

depends on whats the choke in the system.... exhaust turbine as John says is most likely.

bigger turbo's, compare their 1.5bar boost power levels. K03, K03s, VF34, GT28, GT30................. they are rising in proportion to their sizes. (same boost more mass airflow - bigger units sustain their boost in the rev range hence more bhp which is function on rpm and torque)

Bill. Where do I start?
At the same manifold boost pressure and the same rpm, you will have the same volume of air going into the engine.
Where the turbo comes in is that at a turbo opperating at higher efficiency on the compresser map will heat the volume of air less, so it will have higher mass (slightly). At 6500rpm and 21psi of boost, the difference between a compresser running at 70% efficiency and 78% efficiency is a difference between 131C and 142C compresser outlet temp. This equals about a 2.7% difference in mass flow (note mas not volume)

Now this doesn't take into account the density recovery of the intercooler. A 70% thermally efficient intercooler with a 20C ambient condition will drop these outlet temps to 57C and 53C, so post intercooler the density differences will be 1.3%. This doesn't take into account the heat sink of the mass of the intercooler either, so differences would be even less untill the IC is heat soaked.

So at a fixed manifold pressure the difference in mass flow between a super efficient (not necessarily bigger) turbo and a crap one is about 1-1.5% mass flow rate into the engine, so bugger all.

The real benefit of the larger turbo is reduced pumping losses on the turbine side and therefore more power at the crack from the same airflow rate through the engine.

Look at any logs of airflow at 21psi from guys running 3071's or 2871's, or 28rs, or IHI, all of which will hold 21psi at 7000 on a small port head and they all flow 240-250g/s. They will all make similar peak power (within 10%) as well. (at the same maintained manifold boost pressure.)


The 3071 could hold 30psi, and thats where the power gain from that turbo will come from.

 

[DPJ]

...........The real benefit of the larger turbo is reduced pumping losses on the turbine side and therefore more power at the crack from the same airflow rate through the engine..........

Please could you expand on that slightly John?