DPJ's GTRS Eliminator Install and Development

[DPJ]

2% duty cycle at 7k. WTF.

Get a boost controller on it and crank it up! Timing logs look spot on as well now.

A boost controller is what's doing it Phil.

I've got an MBC piped in parallel with the N75. (Boost signal tees and goes to both MBC and N75. Their actuator lines tee back together before the actuator)

The MBC has a bleed hole on the actuator side, so that while it holds boost, it bleeds the N75 signal away.

I just need to tweak it up a little more now...........

 

[PhilW]

Keep goin and keep an eye on CF's and your fuelling. But you already know that.

Which mbc you got? Got any pics of the setup as well?

 

[DPJ]

Keep goin and keep an eye on CF's and your fuelling. But you already know that.

Which mbc you got? Got any pics of the setup as well?

Yes Phil, CFs and fuelling are top priority.
I've kind of given up on taking the timing beyond T9 at the moment, I don't seem to be able to keep the CFs down consistently enough. The WMI is also running on a 175 nozzle rather than 225, and at 150psi rather than 180. Although I had good results on a 20% mix, I'm trusting that running 50% will pay off in cooling at a slightly higher boost level.

I don't want it to spike at more than 2.0 bar, what do you think would be a safe target for boost across the range?

I just got a cheap ebay 2 port MBC to try at the moment. That's sitting up top next to the charge pipe. The rest isn't really photo material as my N75 is tucked way down the back behind my 'teapot' tip insert.

 

[PhilW]

Sounds like its flying then dave.

Hows the part throttle surging or general running with the bleed valve? Any issues?

 

[DPJ]

Sounds like its flying then dave.

Hows the part throttle surging or general running with the bleed valve? Any issues?

I can get it to surge if I feather the throttle, but it's easy to avoid.

 

[PhilW]

Thats not too bad then.

Is this how yours is set up?

http://i33.photobucket.com/albums/d86/loxxrider/mbcwithn75.jpg

 

[DPJ]

Is this how yours is set up?

http://i33.photobucket.com/albums/d86/loxxrider/mbcwithn75.jpg

Yes.
'Useful to drop boost down to safer levels....'

 

[PhilW]

LOL. My next thing to do i reckon.

 

[Wilko]

Dave, Mork
I think you're mistaken about the maf being scaled. The stage 3 code is based on a cupra R code which uses the same maf as you. This means that the readout from vag com should be right.
It also ties up if you look at your airflow vs rpm, it suggests that at 4700rpm you're achieving >95% volumetric efficiency assuming 26-27psi of boost (guess as map sensor is maxed), and at 7000rpm you're at 81-82% VE which on a small port with standard cams would make sense.

Dave. You're on 550's right. Log block 2 or 3 (whichever one shows injector on time), along with afr. I can back calculate airflow from that fairly accurately.

 

[DPJ]

Dave, Mork.................

Dave. You're on 550's right. Log block 2 or 3 (whichever one shows injector on time), along with afr. I can back calculate airflow from that fairly accurately.

Cheers John, I'll log 002/031 tonight.

 

[DPJ]

Well I thought I'd have a stab at working it out myself. (So I'm probably about to reveal something stupid )

Block 002 gives the time an injector is open per cycle in milliseconds.
Divide that by 1000 to give time in seconds.
Multiply by RPM divided by 60 to get time injector is open per second.
Multiply x2 (two injectors fire per revolution)
Multiply by the injector capacity 550cc/min
Divide by 1000 and 60 to get litres per second

Fuel weighs 737 grammes per litre so multiply by 737 to get weight of fuel per second.

Multiply the actual lambda x14.7 x fuel weight to get actual air weight.

Group A:	'002		'031						
rpm	Inj. 	Air mass	Lambda	Lambda	Fuel Vol	Fuel	A/F	Air	Scaling
 /min	 ms	 g/s	Actual	Target	litres	Weight		Actual	
						g/s		g/s	
3360	10.88	78.31	0.774	0.797	0.0112	8.23	11.38	93.67	1.20
3520	11.56	89.64	0.75	0.789	0.0124	9.16	11.03	101.03	1.13
3720	12.24	113.94	0.758	0.805	0.0139	10.25	11.14	114.25	1.00
4000	14.62	141.11	0.789	0.797	0.0179	13.17	11.60	152.74	1.08
4280	15.98	167.44	0.789	0.797	0.0209	15.40	11.60	178.64	1.07
4560	17	190.78	0.797	0.797	0.0237	17.46	11.72	204.53	1.07
4880	17.68	204.31	0.797	0.805	0.0264	19.43	11.72	227.63	1.11
5160	17.34	213.67	0.797	0.805	0.0273	20.15	11.72	236.07	1.10
5440	16.66	215.64	0.782	0.805	0.0277	20.41	11.50	234.61	1.09
5640	15.3	202.14	0.789	0.805	0.0264	19.43	11.60	225.38	1.11
5840	14.96	206.39	0.789	0.805	0.0267	19.67	11.60	228.19	1.11
6040	14.62	215.53	0.782	0.805	0.0270	19.89	11.50	228.59	1.06
6240	14.28	214.5	0.797	0.805	0.0272	20.07	11.72	235.10	1.10
6400	13.94	217.61	0.813	0.805	0.0273	20.09	11.95	240.11	1.10
6600	13.26	217.94	0.797	0.805	0.0267	19.71	11.72	230.90	1.06
6720	13.6	225.44	0.782	0.805	0.0279	20.58	11.50	236.59	1.05
6880	12.92	214.08	0.813	0.805	0.0272	20.02	11.95	239.23	1.12
7000	12.58	214.94	0.797	0.805	0.0269	19.83	11.72	232.33	1.08
7120	12.92	212.36	0.766	0.805	0.0281	20.72	11.26	233.26	1.10
7240	13.26	214.5	0.75	0.805	0.0293	21.62	11.03	238.35	1.11
7240	11.9	205.61	0.75	0.805	0.0263	19.40	11.03	213.91	1.04
6320	0	1.67	0.922	0.945					
5640	0	11.44	1.991	1.047					
5560	0	12.75	1.991	1.047

Hmmm, I get scaling, but not a constant.

Also, why doesn't the methanol affect the lambda.......

 

[The MoffMeister]

Block 002 gives the time an injector is open per cycle in milliseconds.
Divide that by 1000 to give time in seconds.

dont you times that to get it to seconds?

 

[DPJ]

Block 002 gives the time an injector is open per cycle in milliseconds.
Divide that by 1000 to give time in seconds.

dont you times that to get it to seconds?

10.88 milliseconds
divided by 1000
0.01088 seconds

 

[PhilW]

No, coz that would give you injector opened time of 18-283minutes+ opening time. lol.

Off topic.
On a side note dave, your spool looks slower using the MBC.

 

[The MoffMeister]

a milli second is a 1000th of a second though

 

[DPJ]

On a side note dave, your spool looks slower using the MBC.

The run above wasn't a good example, Phil - I was in 4th far too early and it bogs down. Most of the runs I do now, I'll boot it in 3rd to about 4.5k, then change (slowly) to 4th to start the power run.

a milli second is a 1000th of a second though

Blink and you'll miss it.

 

[ibizacupra]

methanol will effect lambda - does on mine big time. 50/50

 

[DPJ]

methanol will effect lambda - does on mine big time. 50/50

That's what I would have thought, Bill. It doesn't seem to affect mine.

 

[ibizacupra]

strange one.. mine went from a 0.75 to 0.80 lambda on full chat down to 0.65 when water/meth was running. I had to trim the fueling back to compensate for it. (its bogged the thing down)

 

[DPJ]

strange one.. mine went from a 0.75 to 0.80 lambda on full chat down to 0.65 when water/meth was running. I had to trim the fueling back to compensate for it. (its bogged the thing down)

Strange indeed.
Your wmi is set up correctly, so at first onset of max boost, you've got 28ccs of water/methanol going in for every 100cc of fuel. (WMI 22% of total volume.)

Assuming a 50% wmi mix and the methanol is all burned, and it makes the mixture richer
89% of a .75 lambda is 0.67 - as revs increase the proportion of methanol would drop, so lambda would go up?