Jump to content

Does a Link G4+ meet my requirements?


Loupoz

Recommended Posts

Hi, just signed up to ask this question.

Im planning a high HP NA build for my E28 M5 with a S38 engine. I want it to feel like a more modern engine, in terms of bells and whistles. Ive got all the mechanicals planned out pretty good, but im searching for an engine management that meets my requirements, they are as follows:

 

DBW Control

Downshift blip. (revmatching)

Knock control

Peak and hold injector drivers.

Fully sequential injection and ignition.

Possibility to view live data on android device - Oiltemp/pres. EGT, AFR minimum. 

Barometric correction.

Closed loop lambda (O2) control.

EGT input.

Cruise control.

 

Would also like recommendations for what sort of actuator to use to control the ITBS.

 

Regards Poul

 

 

Link to comment
Share on other sites

You can see a comparison of the main feature differences between our different models here: https://www.linkecu.com/products/ecu-comparison-chart/

As you can see from that table, the Xtreme, Fury or Thunder will cover most of what you ask.  The Thunder is the only one with built-in thermocouple inputs but you could still get EGT's into the others using an external amplifier. 

Although all of these ECU's will also do downshift blip, I feel our blip strategy may not have enough functionality to work well in a road car with h pattern gearbox with synchros.  I have only seen it used in race cars with sequential dog boxes where the shifts are quite fast and there is little variation (in terms of driver input) from shift to shift. i.e. the driver is always shifting as fast and hard as possible.  In our present firmware the main blip rev match is done by throttle control (or blip solenoid) only, whereas in the few road car GCU's I have seen the blip strategy is quite a bit more complicated with an overblip then a cut applied immediately to get the rev match more exact.  They also normally take multiple other inputs into account in the shift strategy such as brake pressure and wheel speed etc.  I have never tried it in a road car so this is just me making an educated guess but thought it should be mentioned upfront.

Link to comment
Share on other sites

Adam I thought about that as well.   

I did also ponder on the last Ecutek car I tuned.  They have a blip strategy that watches the clutch and brake switch and the order that they are pressed which should be able to transfer over with some imagination.  The way they do it is if the rpm is past a set point and you are on the brake and then press the clutch to down shift, it will blip a specified amount for a specified time frame.  Should be able to make that work with the use of some virtual auxs.  

Link to comment
Share on other sites

6 hours ago, Adamw said:

You can see a comparison of the main feature differences between our different models here: https://www.linkecu.com/products/ecu-comparison-chart/

As you can see from that table, the Xtreme, Fury or Thunder will cover most of what you ask.  The Thunder is the only one with built-in thermocouple inputs but you could still get EGT's into the others using an external amplifier. 

Although all of these ECU's will also do downshift blip, I feel our blip strategy may not have enough functionality to work well in a road car with h pattern gearbox with synchros.  I have only seen it used in race cars with sequential dog boxes where the shifts are quite fast and there is little variation (in terms of driver input) from shift to shift. i.e. the driver is always shifting as fast and hard as possible.  In our present firmware the main blip rev match is done by throttle control (or blip solenoid) only, whereas in the few road car GCU's I have seen the blip strategy is quite a bit more complicated with an overblip then a cut applied immediately to get the rev match more exact.  They also normally take multiple other inputs into account in the shift strategy such as brake pressure and wheel speed etc.  I have never tried it in a road car so this is just me making an educated guess but thought it should be mentioned upfront.

Okay, so theres no way to make it behave like a new BMW, where if you dont release the clutch, while coasting it just keeps on at an engine speed that matches the gearbox speed?

How configurable is the blip feature?

Anything else where ill encounter problems?

Link to comment
Share on other sites

8 hours ago, Brad Burnett said:

Adam I thought about that as well.   

I did also ponder on the last Ecutek car I tuned.  They have a blip strategy that watches the clutch and brake switch and the order that they are pressed which should be able to transfer over with some imagination.  The way they do it is if the rpm is past a set point and you are on the brake and then press the clutch to down shift, it will blip a specified amount for a specified time frame.  Should be able to make that work with the use of some virtual auxs.  

Ours would work at least as good as the ECUtek strategy from what I have seen but that is a long way off the OEM BMW type strategy the OP is looking for.  Both ours and ECUtek use a fixed amount of throttle opening to achieve the blip, there is no feedback based on actual Vs target RPM.  So lets say you need a 50% throttle opening to achieve the correct torque increase for a fast downshift.  If you next do a slow gear change the same programmed 50% blip will increase RPM far more than needed.

 

7 hours ago, Loupoz said:

Okay, so theres no way to make it behave like a new BMW, where if you dont release the clutch, while coasting it just keeps on at an engine speed that matches the gearbox speed?

As far as I know there are very few aftermarket ecu's with OEM level of functionality in this regard, for this level of control you are really getting into the league of a dedicated GCU and many many hours of shift tuning.

 

7 hours ago, Loupoz said:

How configurable is the blip feature?

I suggest you download PC Link and have a play around.  Attached is a map that has downshift blip set up with quite typical settings. For a road car I would probably use the predictive blip end mode instead but you will get the idea. 

S54 NA Circuit car.pclr

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...