Jump to content
Flandrs

Launch problems

Recommended Posts

Hi

 

I have been experiencing alot of problems too get my car not too boog away.

It clearly doesn't matter if i have 0,5bar off boost or 2bar off boost it still boogs.. 
Exit decay rate was set too 2% 20ms and raised ot too 98% and it worked a little better but still the same problem.

What shall i do? get a log off all that has with launching too do and get them up here?

Also i would need a faster revlimit! if gear is missed the engine clearly over reving 12000rpm++ is hard limit the solution?

 

 

Share this post


Link to post
Share on other sites

Ok I see some of your problem is the launch ignition trim activation is set too close to the launch RPM so it is continuously bouncing on & off.  Try setting ignition trim activation to 6000RPM.  I think with more consistent retard you should see higher launch boost.

Also if your engine has solid lifters then I think you would get a better result by using ignition cut instead of fuel cut.  If you have hydraulic lifters it would pay to stick with fuel cut.

0WV6IlN.png

 

Share this post


Link to post
Share on other sites

So now i have been out testing again, works pretty good but still sometimes it boogs.. 

It cuts really hard even as i have fuel cut as limiter. What can i do to smooth it out to be more like a rev limit?

I played a little with "limit range" and ign trim activation

 

I also run 8 injectors with staged injection, perhaps it doesn't matter i don't know.

 

Would appreciate all help i can get to sort this out

Flanders map.pclr

Flanders logg 5.llg

Flanders log 1.llg

Flanders log 2.llg

Flanders log 3.llg

Edited by Flandrs

Share this post


Link to post
Share on other sites

Ok I see some of your problem is the launch ignition trim activation is set too close to the launch RPM so it is continuously bouncing on & off.  Try setting ignition trim activation to 6000RPM.  I think with more consistent retard you should see higher launch boost.

Also if your engine has solid lifters then I think you would get a better result by using ignition cut instead of fuel cut.  If you have hydraulic lifters it would pay to stick with fuel cut.

0WV6IlN.png

 

Why stay with fuel cut on hydraulic lifters though? Is it a specific recommendation on the 4g63 head? 

Share this post


Link to post
Share on other sites

Why stay with fuel cut on hydraulic lifters though? Is it a specific recommendation on the 4g63 head? 

With aggressive ignition cut limiting on a engine with hydraulic lifters the large bangs in the exhaust port/manifold can lift the valves slightly and cause the lifters to "pump up".  This can play out in different ways depending on the valve train design.  SR20's for instance are almost guaranteed to through a rocker off.  Some other engines pump up enough for the valves to hit the pistons.  I dont think the 4G63 usually has much drama in this respect but I personally still wouldnt use prolonged ignition cut limiter if I had hydraulic lifters.   

Share this post


Link to post
Share on other sites

I use fuel cut to keep the head gasket in tact as well an not denting my camshaft lobes. With proper ign retard you can have pretty similar results that are much safer in my opinion. 

That erratic ign timing is def a problem. I can help setup.

https://www.youtube.com/watch?v=W_taQNmDW6c

Launch.png

what do you think about a proper Launch configuration for an R33 gtr high powered?

Share this post


Link to post
Share on other sites

Well my engine doesn't sound like that at all, it spits fire alot with fuel cut, but as it was a note that ign cut should be used with staged injection

i changed to ign from fuel and it cut alot harder than before and probably My headgasket died too.

i want a launch that Are more like a rev limit without bangs but builds enough boost.

it still keeps turn on and off 

dont know How too get it to work!

IMG_2420.JPG

Share this post


Link to post
Share on other sites

what do you think about a proper Launch configuration for an R33 gtr high powered?

I can help you out. I carry this same strategy into all the cars I tune and it works really well.

Here is a little revision i did to make it simple to adjust for ya.

Flanders map.rev1.pclr

Edited by Jwhalen07

Share this post


Link to post
Share on other sites

With aggressive ignition cut limiting on a engine with hydraulic lifters the large bangs in the exhaust port/manifold can lift the valves slightly and cause the lifters to "pump up".  This can play out in different ways depending on the valve train design.  SR20's for instance are almost guaranteed to through a rocker off.  Some other engines pump up enough for the valves to hit the pistons.  I dont think the 4G63 usually has much drama in this respect but I personally still wouldnt use prolonged ignition cut limiter if I had hydraulic lifters.   

Thanks for the reply, it makes sense. My engine is a CA18DET which has cams directly over the valves and i never had such issues although my cams are only 8.5mm lift from memory. I only use ignition cut on launch control though at the moment :)

Edited by TnF

Share this post


Link to post
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.

Loading...

×
×
  • Create New...