Kamotors E30-Turbo to ITB M20

[digger]

i balanced mine perfectly but forgot to fully tighten one of the lever clamps and few days later i started getting rough running/light popping at light load 0-14% elsewhere it was fine. nothing i did with adding or subtracting fuel fixed the light load issues until i found that the lever could slip very slightly with a tiny bit of force. fully tightened it up and re-synced them and the issues disappeared.

as bullet ride alluded to some of the cylinders in my case 1-4 were running either rich or lean but the WB saw the average of all 6, no matter what the average is all of the cylinders individually need to be good

[ForcedFirebird]

We use a sync tool like this...

[kamotors]

I can get this locally, would it work as well? I have a post tb vac port added to each bank

[LJ851]

I can get this locally, would it work as well? I have a post tb vac port added to each bank

It would work better, that is the right way to do it.

[TeXJ]

Should do a video on how to do that.

[IronFreak]

Should do a video on how to do that.

[kamotors]

guess ill grab one today and get em synced up, it makes more sense that its out of sync as my afr reads pretty normal, nowhere near what should be backfiring and what not.

[LJ851]

guess ill grab one today and get em synced up, it makes more sense that its out of sync as my afr reads pretty normal, nowhere near what should be backfiring and what not.

Sync them at idle and also at around 3k rpm (no load). Sometimes linkage can alter the sync while the throttle is pressed. If there are throttle stop screws for each TB, you can use them to set idle sync and them use the linkage adjustments to perfect part throttle sync.

Sometimes a compromise is necessary.

[Bullet Ride]

Just out of curiosity how did you set them when you put it all together?

An easy way to get them 95% there is to get a really small diameter drill (i.e. less than 1/8", 1/16" would be good or 3/32")and use the shank of it as a feeler gauge. Just set your idle screw so that the throttle attached directly to the linkage arm is open enough to get the drill past the plate (right at the bottom where the gap between the throttle body and plate will be the largest) with a bit of drag, then set the adjustment screws on the other throttles so they have the same amount of drag. Then crank your idle screw back to where it was and you're good to go.

[kamotors]

Sync them at idle and also at around 3k rpm (no load). Sometimes linkage can alter the sync while the throttle is pressed. If there are throttle stop screws for each TB, you can use them to set idle sync and them use the linkage adjustments to perfect part throttle sync.

Sometimes a compromise is necessary.

Currently idle is very smooth and stable and wot is good its just the on throttle transition thats quite poor and if lugged itll load up and bog. I noticed the linkage can sometimes stick about 1mm before closed and cause a hanging idle as well.

[digger]

Currently idle is very smooth and stable and wot is good its just the on throttle transition thats quite poor and if lugged itll load up and bog. I noticed the linkage can sometimes stick about 1mm before closed and cause a hanging idle as well.

i made a throttle return spring that pulls on the arm that the throttle clip is pressed into so that there is a decent amount of force pulling the throttle lever closed against the stop so its always consistent hard against the idle stop, it also is tuned to the resistance i like in the pedal feel. the small spring on the TB 5-6 is only intended as a safety item.

[kamotors]

SO it was worth it to know they are all reasonably synced now, however still backfiring!, I can look down the trumpets and see flames:(

here is a quick how to as its very simple.

#1 need to have access to vac lines for each runner( I did this all preemptive in hopes of a bit of speed density driveabilty and knowing it helps tuning)


#2-locate your adjusters


#3-setup your sync tool and get other tools needed like a flat head screw driver, allen wrench and an 8mm.


#4-calibrate your tool off of the NON adjustable set(cyl.5 and 6).


#5-calibration done (close enough)


#6 hook up your ITBs to each port mine were very far off.


#7 tuned to around 1300rpms about as close as I could get them.


however uploading video of how bad it still pops just holding rpms around 3k.


video

[LJ851]

Are the TB's in sync at 3k rpm?

[kamotors]

Are the TB's in sync at 3k rpm?

pretty darn close, I added the video above^ I hold it at 3k and film the tool

[LJ851]

I would check all the cylinders sync together. Put all four channels of the sync tool on the front four cylinders and then on the rear four cylinders. This will verify all cylinders are in sync and you don't have a situation on a cylinder you are not measuring.

I would also try to get the sync a little closer, but that's me.