2nd e30, 87 Lachssilber Revival

[ForcedFirebird]

You "can", and use the throttle stop for idle, just keep in mind it will be temperamental with the first start of the day - and may need to be adjusted seasonally.

[Reichart12]

Similar, Digger. I cap the ICV (if they are using one), get all throttles 100% closed, make sure the engine won't run, which would indicate vacuum leaks. then I adjust the center stop just enough top get idle. Balance the two outer sets to the center, then close the stop, add the ICV back in the loop - or leave them cracked open if the ICV was deleted.

At first I didn't think the vacuum type was going to work well, but was kind of forced to use it with the Dbilas car we tuned, now I prefer it. The gauges I use have a buffer valve to keep the needle from fluttering. I'll actually be using it today on a RHD equipped m20. Hoping the weather stays nice so we can do a road tune as well, hurricane Nicole just grazed us last night.

If I understand this first part correctly, I can totally remove the ICV? Put a cap on the fitting from the distribution block and tuck the wire out of the way? So far I haven't done anything with the ICV so if I could skip it and not have to route an additional vacuum line to the plenum, that would be ideal.

[ForcedFirebird]

Similar, Digger. I cap the ICV (if they are using one), get all throttles 100% closed, make sure the engine won't run, which would indicate vacuum leaks. then I adjust the center stop just enough top get idle. Balance the two outer sets to the center, then close the stop, add the ICV back in the loop - or leave them cracked open if the ICV was deleted.

At first I didn't think the vacuum type was going to work well, but was kind of forced to use it with the Dbilas car we tuned, now I prefer it. The gauges I use have a buffer valve to keep the needle from fluttering. I'll actually be using it today on a RHD equipped m20. Hoping the weather stays nice so we can do a road tune as well, hurricane Nicole just grazed us last night.

[digger]

I should be clear that while these are economical itb the quality is more than adequate to achieve good results. The setup and tuning are critical but not overly difficult

[Reichart12]

They will need adjustment periodically.

I stopped using that flow meter, they work "OK", but are a pain if you have an air box. Had a customer come in work a few months ago with DBilas ITB's that balance was so horrible, sounded like it was running on 3 cyl. My neighbor is an outboard mechanic and loaned me his carb sync tool, works so much better, and is just generally makes it a faster process all around

This was definitely the style I would see more often when doing some Google searches about ITB syncing.

Nice work on the ITBs- do you plan on trying to retain cruise? That's such a killer for me, as I do a lot of highway driving.

Are you running trumpet filters?

This car never had cruise and honestly I don't ever use it in my truck either so that was a non issue for me. Currently open trumpets but I do plan to put the plenum air box on with a singular filter.

It would be different if the throttles had individual bypass screws so that once you balanced the blades using the flow tool and then enabled the ICV you could do secondary balance by trimming air flow using the individual bypass without moving the blades using a vacuum type setup. However since these are are somewhat budget ITB they don't have the individual bleeds like the more expensive setups do. This is why when you setup the ICV everything needs to be as close as possible to identical on each cylinder e.g. each nipple identical and i drill them so they are the same, same hose lengths and so on and is why i went to a log type tube for the ICV similar to used on S54B32/S50B32

I always appreciate the knowledge coming through. This has been the only set of ITBs I've been exposed to so it's definitely interesting to hear about the variations that might exist between different sets and different price points.

[digger]

i hadn't adjusted mine for over 5 years without issue and only needed to after i needed to remove them. i did do some massaging of the end of the set screws to grind them flat, and i might have changed out some wear items e.g. the little tabs, for harder/more wear resistant materials (stainless) but mine are older versions.

i always balance the throttle with the ICV nipples closed off (i.e. ICV inactive) to eliminate the variable and i use the flow tool.

I have tried several different vacuum type gauges that exist and there is no benefit in moving away from the flow tool IMO.

It would be different if the throttles had individual bypass screws so that once you balanced the blades using the flow tool and then enabled the ICV you could do secondary balance by trimming air flow using the individual bypass without moving the blades using a vacuum type setup. However since these are are somewhat budget ITB they don't have the individual bleeds like the more expensive setups do. This is why when you setup the ICV everything needs to be as close as possible to identical on each cylinder e.g. each nipple identical and i drill them so they are the same, same hose lengths and so on and is why i went to a log type tube for the ICV similar to used on S54B32/S50B32

[AWDBOB]

Nice work on the ITBs- do you plan on trying to retain cruise? That's such a killer for me, as I do a lot of highway driving.

Re: adjustments. Everyone I know that has run these has had to make fairly frequent adjustments, which is what scared me away from using them on Linda, as I wanted the car to be a worry free driving experience.

Perhaps you could guide us along your journey with them.

Are you running trumpet filters?

[ForcedFirebird]

They will need adjustment periodically.

I stopped using that flow meter, they work "OK", but are a pain if you have an air box. Had a customer come in work a few months ago with DBilas ITB's that balance was so horrible, sounded like it was running on 3 cyl. My neighbor is an outboard mechanic and loaned me his carb sync tool, works so much better, and is just generally makes it a faster process all around: https://www.amazon.com/P1-Tools-Moto.../dp/B07MJZ1RFB

[Reichart12]

I wonder if ITBs need to be readjusted at some point early on after initial setting as the fresh parts wear in?

I'd imagine they constantly need adjusting. After my first drive around the block I had to retighten the set screws on the throttle pairs. It's better now but I will probably check the set screws and flow rating before any long trips or autocross events.

[roguetoaster]

I wonder if ITBs need to be readjusted at some point early on after initial setting as the fresh parts wear in?

[Reichart12]

Mostly just a photo dump. Had to replace the o-rings for the bitch tube and decided to replace the tube, spring, and washer too. All in for ~$35. I believe that fixed the main oil leak I had from installing the ITBs. Still maybe something coming from the oil filer housing/cooler lines but not positive. (Now my truck, I know where that fat oil leak is coming from, but I digress). Have only tuned the car up to about 40 mph and below 4500 rpm. Lazy me. But I might take this thing to work this week. Stay tuned. Anyways, should have a Youtube video coming out in a couple days covering this change but I know you all appreciate pictures more.

[Reichart12]

CF hood?

Trunk! But I miscalculated fiberglass resin so my mold is thin. The part side looks good though.

Glad to hear ITBs are making progress. The gas lids are looking better. Looks like maybe trimmed a bit small?

Not so much trimmed small but misaligned bonding to the metal backing. The hinge part sits too close to the edge and that just messes up all the body gaps.

[moatilliatta]

Glad to hear ITBs are making progress. The gas lids are looking better. Looks like maybe trimmed a bit small?

[2mAn]

Still not the best part out there but it was fun to make and I like how it looks. It was the last piece of my fiber roll and I managed to misalign the fibers. Still a lot of difficulties getting a good even resin layer. I bought a vacuum pump and vacuum bagging material but need to iron out some kinks there. Not much warm weather left to make much more but I may just try to squeeze one other part type in before winter...

CF hood?

[Reichart12]

Tried to toss these photos up the other day but couldn't get r3v to open. Then forgot for a few days. Still not the best part out there but it was fun to make and I like how it looks. It was the last piece of my fiber roll and I managed to misalign the fibers. Still a lot of difficulties getting a good even resin layer. I bought a vacuum pump and vacuum bagging material but need to iron out some kinks there. Not much warm weather left to make much more but I may just try to squeeze one other part type in before winter...

Video on the process

https://youtu.be/5qoWX_KtIXI

Couple photos I took