3B Turbo Boost Compensator Alternative (1 Viewer)

[yotahed]

Hey all,

There have been a lot of questions about the need for a boost compensator on a turbo'd 3B. Although it doesn't NEED one, there is something someone on this board mentioned to me in my 3b swap writeup. If you fit a governor spring from a 1977 240D mercedes pump, it will act like a boost compensator. The spring is a bit longer(25-30mm) and is spun from a thinner wire (.5mm smaller- 1.5mm)
I am told this gives a better fuel curve for a turbo application and stop the smoking at low revs before spool up.
Now, I have had a hell of a time finding this spring, but some nice chap on a merc board gave me the mercedes part number for the spring itself (lucky!)
If anyone is interested, they have to be ordered from germany, and run about 9 bucks from the dealer. guy says about 14days delivery time. Im gonna go for it.

this is the part # for the spring

A0010740393 I am told sometimes the A is left out. you can order it from various merc parts sites, but they are mostly in the UK and Russia.
If anyone wants one Im going to the dealer tommorow. Ill check my pm's and this post before paying.

Cheers All!

 

[yotahed]

Springs Arrived

Hey all

So the governor springs arrived today from Deutschland. Ill go to Kelowna tommorow to pick them up from the Mercedes dealer. Due to low interest in this i only ordered 2, and the 2nd is spoken for. But at 10 bucks a pop, y'all can order your own dam spring lol.
Not sure how low their stock is as I was told they had to source the 2nd from else where...
Anyway, I will install tommorow and report the results.
cheers

 

[yotahed]

Well, quite a difference. to be fair:
1. Full tank of fuel
2. Turned the fuel down a tad.
3. Max boost at 15psi (rarely)
4. Im runnin 33's with 4.88s h55f

First impressions:
Quicker to build boost from a stop.
Quicker to build boost while cruising. slower egt climb when flooring it on the flat.
Egts seem to match the boost level. Capping the pressure at 10psi yeilded 1000f max flooring it in 4th steep hills. increasing boost to 15 yeilded 1100f noticeable power increase, no fuel screw changes.
The initial fuel setting was too low so i turned up 2 full turns right away.
Playing with the fuel screw yeilded even quicker spool up, faster response and yes much higher egts.
Seems the boost and fuel now play off each other whereas before it seemed as though fuel controlled boost level and spool up.
Any way im happy with my 10 dollar investment.
First day. will update more as i tinker more
Cheers

 

[Dbradford04]

pictures?

 

[yotahed]

Ill post a few pics of the spring difference later today. i also replaced the HAC with a solid bolt. i had issues with the end moving under boost, thus over fuelling a bit. the bolt size is 22mmx1.5 thread pitch. works like a charm

 

[Dbradford04]

timely..getting ready to mount my turbo soon. would love to see pictures of your set up.

 

[cody c]

Interesting, and sounds like a cheap mod to boot.

It would be nice if you post some pictures of how its done for the rest of us!

 

[yotahed]

Hey guys
In the first pic you can see the differences between the two springs. wire thickness and length.



In the 2nd is my screw setup. simple bolt and original jam nut in place of HAC. HAC was non functional and the pin moving under load.
Manual shut down cable in place of edic

Allen head bolts in place of stupid flat heads.



Boost controller and wastgate

 

[yotahed]

Of any are wonderin how to install, it takes all of 5 minutes. just pop off the spring cover in the 3rd pic swap spring, put a tiny bit of grease around outer ring (dont get any on the diaphram) and pop her back together. adjust fuel as needed. highly recommend egt and boost guages before installation or playing with fuel or boost in any way. this give a clear indication of proper fuel and boost levels.
Cheers

 

[Traveller]

Hi yotahed, now take the next step, adjust the max rpm, if you look at the eploded vieuw you see it works by pushing the rck bck by the linkage to the vacuum governor. This starts at about 2800 rpm's. So if you turn up the max rpm, the

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[Traveller]

Hi yotahed, now take the next step, adjust the max rpm, if you look at the eploded vieuw you see it works by pushing the rck bck by the linkage to the vacuum governor. This starts at about 2800 rpm's. So if you turn up the max rpm, the

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Sorry wrong button. Where was i....
If you turn up the max rpm screw the rack wil not be restricted by this.

Mine starts to decrease at 4200 rpm.

Dont't be scared, i had my 3b. Running 5400 rpm and it stil runs..

Mike

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[yotahed]

Do you have a pic by chance lol we are talking about the rpm screw and this is different than the arm on the out side of the pump? is it on the back under the diaphram/governor cover?

 

[Traveller]

Do you have a pic by chance lol we are talking about the rpm screw and this is different than the arm on the out side of the pump? is it on the back under the diaphram/governor cover?

Yep, under the governor. This is a ring with bals the flys outwards an then presses backwards that returns the rack. Now if you understand this you know this sarts at lower rpms an increases upwards. So turn it outwards so the decrease starts at higher rpm's.

I mounted a butterfly valve from a 2h engine ( adjust the bolt patern) and fine tuned it al by slightly turning the vacuum/presure pipes in the valve body ( the back one slightly turned down )

It's lots of fun trying to undstand and adjust ( even by trial and error ) and end up with just the excact setting you want.

At this moment i have full power and no black smoke(loss of fuel) , a good every day runner that keeps up with the modern hacky tacky fouky wouky....

Just one advice, always start with new filters and good setup like pump timing, otherwise you won't know where you came from. Found out tht timing the pump with a lamp and a electronic pulse feeler on the first injector pipe near the injector gives the best result.

If you want to step up further, overhaul the injectors and adjust the pressure to 145-150 bar for better results in combination with an increase (slight) of the pump timing.




Subscribed... Will follow your results and step in if i can ad somting to your experiences..


Regards,

Mike

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[yotahed]

Some awesome info Mike. ive been on the hunt for a 2h venturi. But that can wait a bit. i do have an extra set of injectors so ill get them rebuilt to a higher pop pressure ( around 1850psi from 1650psi+/-)
Also, for the max rpm adjust, how do you know when its adjusted proper. do you adjust, puy back together and test and then repeat as neccesary or is there a certain number of turns to get close?
Sorry just dont wanna over adjust or anything

Thanks Mike you rock!

 

[Hulsty]

Sorry wrong button. Where was i....
If you turn up the max rpm screw the rack wil not be restricted by this.

Mine starts to decrease at 4200 rpm.

Dont't be scared, i had my 3b. Running 5400 rpm and it stil runs..

Mike

Sent from my iPad using IH8MUD... fun starts where the road ends

Interesting, what is your governor now at? When I spoke to a tuning shop about dyno tuning my 13BT they said they could get a little more fuel by upping the governor, similar pumps I guess. I'm not to keen on raising the governor though as I spend a bit of time now it now already....

 

[cicak]

im not worried about the rack im worried that you are exceeding the max revs what about the cam etc valve open/close durations will it handle it or will it be just too much and go bang>

 

[yotahed]

Well i dont think upping the govenor would neccesetate actually driving and revving to that rpm, but simply raising the rpm that the fuel starts to cut back. so instead of the stock setting cutting back at 2800 you would get full delivery until YOUR desired redline. I dont usually take mine above 3000 rpm ever, but raising the governor would give me consistent fuel delivery to this point. obviously you would need tp excercise caution when down shifting etc. So as to not over rev the little guy. make sense?

 

[Hulsty]

I dont usually take mine above 3000 rpm ever, but raising the governor would give me consistent fuel delivery to this point. obviously you would need tp excercise caution when down shifting etc. So as to not over rev the little guy. make sense?

Ahh mines the opposite, i regularly shift past 3000rpm and hold it flat offroad. Might have to break out the manuals and inspect the fuel curves again.

 

[yotahed]

Yea i know i could rev her a bit more without worry, the redline is around 4200rpm in the manual. i just feel all the power is down low from 2100 to around 2900 so thats usually where i drive it with the odd blast to 3300. and i run around 15 psi.

 

[Hulsty]

Whats your torque peak at? In mine the torque peak is very much at 2200rpm