Turbo 3.2 Carrera Ignition Upgrade Pathway

[GJF]

If you take your current ignition map and delete everything from 160 across and up. Then shift the entire map up. Then fill the bottom section of the map 1 degree per cell you would have a good base. The ignition map you have now is VERY MILD, a little too mild. It is urrently not one for rapid throttle response. Shift the map and you should gain much more response.

[Raceboy]

RagingBull, it is not fixed lol. Regular FPR will hold the fuel pressure at 3 bar over intake manifold pressure, that's why it has vacuum reference line to it. At idle with vacuum fuel pressure is less than 3 bar, with say 1 bar of boost fuel pressure is 4bar with regards to ambient air pressure. It is called linear fuel pressure regulator.

RRFPR adds more fuel pressure than linear, for example at 1bar boost fuel pressure is not 4 bar but 5 bar of whatever it is set to.

[RagingBull]

Raceboy, thank you for the clarification - my mistake as I did not realize the stock FPR would deliver 1:1 as boost is applied. With a naturally aspirated 3.2, I know the Fuel Pressure is rock steady from vacuum to ambient.

[Raceboy]

Fuel pressure will be lower at idle (depending how strong vacuum the engine makes) and at full throttle it will be at the FPR rated value when n/a (since full throttle with n/a means ambient pressure). Also can vary few kPa since engines are different (some have intake restriction -> vacuum at full throttle), also at what altitude the car is.

With very agressive cams (and thus noisy and very low vacuum signal) it is better to remove vacuum reference altogether in n/a applications as that stabilises fuel pressure and makes for easier idle tuning.

[Pork Chops]

Originally Posted by GJF

If you take your current ignition map and delete everything from 160 across and up. Then shift the entire map up. Then fill the bottom section of the map 1 degree per cell you would have a good base. The ignition map you have now is VERY MILD, a little too mild. It is urrently not one for rapid throttle response. Shift the map and you should gain much more response.

Thanks for the feedback 👍

[Pork Chops]

Originally Posted by RagingBull

I believe the stock headers / heat exchangers, J-pipe, and 0.82 A/R housing will all contribute to the lag you are seeing (and the response / feel).

I do not know how the system can adjust fuel pressure with boost as it currently stands. You have the higher power pump and the large injectors but the fuel pressure itself is fixed throughout the range. Typically I understand turbo 3.2 applications using a BEGI RRFPR or similar. That being said, your AFRs would show if this was truly a problem. I would recommend a chat with Turbokraft or Protomotive to shed some light unless our knowledgeable fellow members can chime in.

Thanks for the input 👍

[Pork Chops]

Originally Posted by GJF

If you take your current ignition map and delete everything from 160 across and up. Then shift the entire map up. Then fill the bottom section of the map 1 degree per cell you would have a good base. The ignition map you have now is VERY MILD, a little too mild. It is urrently not one for rapid throttle response. Shift the map and you should gain much more response.

Any further feedback on the ignition map. If anyone could share an ideal or typical map that’d be great.

[GJF]

Every motor is alittle different. It will be close but atleast you would have base to start. Edit your map but save your original for comparison. Dyno time will show you the exact path.

[John at J&S]

Doesn't VEMS have knock control? You should be able to use that as a tuning guide.

PauerTuning (Vic Timpauer) used a J&S that way on a 944, while tuning his Vipec:

Reutterwerk Forums - View Single Post - Rant Rant Rant

Reutterwerk Forums - View Single Post - Pauertuning's Vi-PEC Standalone kit

[Raceboy]

Yes, VEMS has dual knock inputs but that would also require to install knock sensors, route cables and tune noise table.
Should be done by tuner, setting up knock sensing is not something for novice.

[John at J&S]

The brute force approach always works.

I came up with a better way in 1983, while working as a technician in a signal processing lab at Hughes Aircraft.

Shirley and I decided to keep it a trade secret, rather than file for a patent.

That makes marketing very difficult, as you can't really talk about how it works. But, I have gotten carried away a few times and let a secret or two out.

[baloo]

Originally Posted by John at J&S

The brute force approach always works.

I came up with a better way in 1983, while working as a technician in a signal processing lab at Hughes Aircraft.

Shirley and I decided to keep it a trade secret, rather than file for a patent.

That makes marketing very difficult, as you can't really talk about how it works. But, I have gotten carried away a few times and let a secret or two out.

Heya John (J&S),
I have one of your knock sensors, not mounted yet. Also presently planning on using stock computer with Steve Wong chip.
BUT, I am thinking I may go with a RaceBoy VEMS system sometime in the near future.

So, I'm interested in your comment about trade secrets, etc. I don't understand the implications of what youre saying.
Anything I should know in re. to using the VEMS and your unit?

[dannobee]

Here's a stock 78 930 advance curve. Remember, that figure shows dist, not crank advance. From your ignition map, your timing is very conservative up top.

[John at J&S]

It works well and is easy to use.

I'd love to explain how it works, but other manufacturers would say "Wow, why didn't I think of that?"

Here's a video of it on a Mini Cooper, which has a factory Seimans ECU with knock control function. They installed a different pulley for more boost, and added a J&S, and a Snow water/meth system.

In the first run, the water/meth is turned off. The J&S gauge lights up, showing the unit is controlling knock that was missed by the Siemans ECU.

In run two, the water/meth is turned on. As expected, there are no knock detections, showing the water/meth is doing its job, AND proving the J&S was not detecting false knock in the first run.

The J&S was more sensitive than the factory knock system, while avoiding false knock detections. All without setting up a noise table, knock amplifier gain, etc.

https://www.youtube.com/watch?v=tjA8xiPd3SU

[Raceboy]

Knock window is essential for filtering out false knock events (since knock occurs only in certain crank angle), VEMS has that. I am not expert in knock sensing like John, but have tuned several cars with VEMS+knock sensors and it also works. Just requires some knowledge of how internal combustion engine works and some experience in tuning in general.

[Pork Chops]

Originally Posted by dannobee

Here's a stock 78 930 advance curve. Remember, that figure shows dist, not crank advance. From your ignition map, your timing is very conservative up top.

Thanks appreciate the info. I regard the tuner, so I’m imagining there is a reason for the conservative ignition map and that’ll be knock. So I’m therefore going to assume it’s knocking too early or easily. Fuel is 98 RON and engine specs are in the first post. Perhaps the weak spark (sorta the original point of this post) means it’s hard to advance the timing?

Cheers.

[John at J&S]

Advancing timing makes the spark easier to fire, as the cylinder pressure is lower at the time of the spark.

Also, when you adjust timing for no knock, you are retarding the whole engine, just to quiet the cylinder that knocks the easiest.

[Pork Chops]

My tuner confirmed he adjusted the dwell when it was being tuned, and it made no improvements. The ignition map is conservative because of knock.

I’m out of ideas....

[John at J&S]

In your first post you say the spark was getting blown out after raising boost. I assume that was solved by increasing dwell?

Increasing dwell increases coil current. Energy stored in the coil goes up with the square of the current. Theoretically, if you double coil current, you quadruple the energy stored in the coil.

Others have analyzed your timing map and have said it's conservative, which can happen when you tune for "no knock".

No one wants knock, but some cylinders knock easier than others. Overall timing is compromised when adjusting for "no knock", robbing power from the more knock resistant cylinders.

Your Vems has the capability to do individual cylinder knock retard. It may even allow you to set timing offsets on a per cylinder basis.

I suggest you learn the system, install the sensors and start tuning/calibrating, or pay your tuner to do some or all of it.

[Pork Chops]

Thanks John, per the above dwell was adjusted and made no improvement in the situation. The tuner will have made decisions based on safety and I have to trust he knows where that point is. He tunes all sorts of high hp turbo cars so I’m going to leave that decision with him. Honestly I’m not going to learn the system any more than I have as I don’t intend to become a quasi tuner. I’d be happy to explore the possibility of individual cylinder knock retard but don’t really want to go back to the dyno until I’ve got a read on why the spark is blowing out.

Originally Posted by John at J&S

In your first post you say the spark was getting blown out after raising boost. I assume that was solved by increasing dwell?

Increasing dwell increases coil current. Energy stored in the coil goes up with the square of the current. Theoretically, if you double coil current, you quadruple the energy stored in the coil.

Others have analyzed your timing map and have said it's conservative, which can happen when you tune for "no knock".

No one wants knock, but some cylinders knock easier than others. Overall timing is compromised when adjusting for "no knock", robbing power from the more knock resistant cylinders.

Your Vems has the capability to do individual cylinder knock retard. It may even allow you to set timing offsets on a per cylinder basis.

I suggest you learn the system, install the sensors and start tuning/calibrating, or pay your tuner to do some or all of it.