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1988 740 16v?

S
The power stage consumption of this car is shocking. Assume you used thermo conducting paste between the alu heat sink and the power stage itself. Like discussed, the combo of this 2x2 coil and power stage is good, the dwell time is what is to be expected, ecu and power stage are compatible and pullup OK. Strange!

Anyways. Looking good, only small things easily fixed and you're back to boosting.

Just checked again:

Nominal dwell is 3.1ms at 14V, voltage correction is just like in the Bosch documentation. This should charge the coil to between 7 and 8 Amps, which does not seem excessive to me. I can always reduce it when I fry the next module. :rofl: Let's hope it's not necessary.

so, you're telling me my wobbly clutch is my new installed oem clutch hose which cost double a steelflex would have cost.. !??

Feel the hose while your friend presses the clutch pedal. I could feel the (used and old) hose physically expanding. At first I thought I didn't bleed enough because it would not disengage, but this was not the case. After changing the line it was fixed immediately. On KL-Racings website they also mention that the OEM volvo line is not suitable for use with stronger pressure plates.

Thank god those security guards noticed this smoke and notified you, could have been a lot worse. Really nice fabrication skills, hope you get everything ironed out.

Thanks! Yes I'm happy the car is still useable, and I'm very motivated to improve it!
 
Feel the hose while your friend presses the clutch pedal. I could feel the (used and old) hose physically expanding. At first I thought I didn't bleed enough because it would not disengage, but this was not the case. After changing the line it was fixed immediately. On KL-Racings website they also mention that the OEM volvo line is not suitable for use with stronger pressure plate

Hmm interesting, I've been running a 763 pressure plate with the stock lines without issues for a couple of years. Maybe I got a fresher line, I assume you have a dutch friendly source for the reinforced line:-P
 
Hi didnt know u had such a nice topic here.
I bought your shortblock for some parts. I'm nealy done collecting stuff to build a b234f for my 242.
Did you reuse old pistons or did u buy new ones and then made valve clearances?
I intended to use (your) 234f pistons in a b230fb shortblock. But maybe better to redrill old pistons.
 
Hmm interesting, I've been running a 763 pressure plate with the stock lines without issues for a couple of years. Maybe I got a fresher line, I assume you have a dutch friendly source for the reinforced line:-P

I got it from here:
https://www.sparks-online.eu/remmen-koppeling/hel-motor-remleidingen/

Hi didnt know u had such a nice topic here.
I bought your shortblock for some parts. I'm nealy done collecting stuff to build a b234f for my 242.
Did you reuse old pistons or did u buy new ones and then made valve clearances?
I intended to use (your) 234f pistons in a b230fb shortblock. But maybe better to redrill old pistons.

Hey! I remember, you were building an NA engine right?
Would be cool to see the results. Why not use the block you got from me? Didn't loo very worn!
Or too much of a hassle to deal with the 16V stuff?
I used B230FK pistons and made recesses for the valves inside the pistons, using Yoshifab's jig.

Small update:

Car has driven 350km now, 0,2 bar boost only.

For some reason the ISV does not work anymore, the ECU fully grounds it now, also in test mode. Not sure if it fried a transistor, but it should be rated for 2.5A so not sure what the problem is here. Will be sorted out

It runs okay. Turbo spools very quick.
Need to work some more on the warm up curves as it is pretty rich when cold.
Also need to tune acceleration enrichment, as it now stumbles on quick tip in of the throttle.
Annoying when doing quick shifts.
I will tune some more this week and take it to work.

What has been done:

- New ball joints and steering joints. (Now the whole front end is new)
- Upgraded to 302mm front brakes.
- Fresh brake fluid
- Installed provent, routed back to turbo inlet.
- Installed classicswede adjustable top mounts

What still needs to be done:

- Alignment
- Clean up engine bay, repaint valve cover/boost pipes
- Drive it and improve tune (will take it easy for another 600km or so)
- Start increasing boost pressure gradually to 1.5 bar. :oogle:
I plan on tuning ignition by directly listening to the knock sensor using headphone amps.

Longer term to-do's:

- Fix 2 rust spots on chassis
- Fix rust on 2 doors
- Build new rear axle with LSD
- Build new subframe

Some pics:




Switching tot 302mm brakes was not as straightforward as on my 940.
I have deleted one of the two front brake lines, and used the following distribution:

240brakejunctionalt2.jpg


I think this is necessary as the 740 MBC has a stepped bore, and routing it like "stock" caused (one of) the rear wheels to lock up first. So I changed it to the layout above and now it brakes very well!

Made a gauge plate:



Provent mount:



Plate for crankcase breather:



Don't have any recent engine bay pictures.
To be continued!

 
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I got it from here:
https://www.sparks-online.eu/remmen-koppeling/hel-motor-remleidingen/



Hey! I remember, you were building an NA engine right?
Would be cool to see the results. Why not use the block you got from me? Didn't loo very worn!
Or too much of a hassle to deal with the 16V stuff?
I used B230FK pistons and made recesses for the valves inside the pistons, using Yoshifab's jig.
Nice. The b234 short block is told to be a hassle to mount in a 240. So found a pretty fresh B230f from '93 so now also have squirters and round gears etc. I've got 8 16V cylinders now. Yours were the best matching to the new block. I'll save the b230f cylinders to keep the jig as an option.

Small update:

Switching tot 302mm brakes was not as straightforward as on my 940.
I have deleted one of the two front brake lines, and used the following distribution:

240brakejunctionalt2.jpg


I think this is necessary as the 740 MBC has a stepped bore, and routing it like "stock" caused (one of) the rear wheels to lock up first. So I changed it to the layout above and now it brakes very well!

Nice i did the same on my 740, forced to go to Hydra's :oogle:.

The stepped bore is in case one of the circuits brake (one is half circumference of the other). If i remembered right, i disconnected the lines that directly go to the front brakes and the rest still intact, wich makes it a diagonal system. My brakes work fine, also @APK, but the brake failure light keeps turned on.

I also found that when using a axle split system like u made; the primary (rear) section of the BMC does the front braks and secundary (front) section the rears.
So good to hear it works well on your car, going to try that out too.
 
Nice. The b234 short block is told to be a hassle to mount in a 240. So found a pretty fresh B230f from '93 so now also have squirters and round gears etc. I've got 8 16V cylinders now. Yours were the best matching to the new block. I'll save the b230f cylinders to keep the jig as an option.

Cool! Be sure to share the results, looking forward to what it will do.

Small update:

Installed/Wired the MAC boost control solenoid.
Increased boost pressure to 0.5 bar (7psi).
Also tuned accel enrichment, car is much more pleasant to drive.
Ignition timing is quite mild, will start tuning it now.

Insanely crappy launch :rofl: but you get the idea:

<iframe width="560" height="315" src="https://www.youtube.com/embed/gCt3eu61Rzc" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>


 
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A little more if you count from the moment when the clutch is dropped. However 6s should definitely be realistisch with a non butchered launch. :rofl:
 
The link shows motorcycle brake lines...have you bought one of these? Or you let them fabricate a custom line for you? Do you have an actual picture of the line?

Tomasss sorry for the late reply.
Yes I let them make a custom line, 80cm length and 2x12mm banjo fittings.
I will make a pic from it on the car.

Small update:

I'm working on a rear axle right now.
I have a spare 940 3.54 rear axle which I will put under the 740, with a spartan locker diff.
Had the axle sandblasted and it was then painted with Brantho Korrux 3 in 1.Quite satisfied with the results! Still need to shoot some pics though.

One problem though, the spartan locker does not fit well in the 940 diff carrier.
The gap between two halves is not within spec (too large).
I can do two things, either use shims to reduce the gap, or use the 740 carrier that's in the car.

I have not been able to find the right shims unfortunately... they should be 40mm ID and 50 or 60mm OD, with a thickness of around 1mm. You can find these shims, but not in a decent (hard) material type. Probably it's the easiest to just use the 740 carrier.

Overall the car drives well! I increased the boost to 1 bar and it's quite fun now!
Already faster than my old 940 with the hy35 and 1.3 bar.
I have to mention though, the power rapidly drops off after 6000rpm. This is probably the nature of the stock camshafts tough. The powerband is large enough with this turbo so I don't really care about that.

Here you can see the gap of the locker halves, caused by the internal pace of the 940 carrier being slightly larger. Also you notice I cut off 3/4th of teeth of the speedo tone ring. :rofl:



Axle:
 
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Update:

JW240 gave me a correct carrier to use with the locker, so I installed this into the painted axle, many thanks.
This axle has 3.54 gearing, the gearing in the car was 3.31.

First impressions: (1.5 hours of driving)

- Way more straigt line grip
- Ratcheting noise inside car is not that noticeable, but it is on the outside of the car.
- Cornering while (heavy) engine braking locks up the diff, can be annoying in tight corners
- If you slightly apply throttle during cornering it does not lock
- Heavy throttle during cornering drives very well and can induce oversteer, which seems easily controllable.
- Operation is not harsh at all.
- The 3.54 gears make the car a lot more pleasant to drive.

It gets annoying when you have tight corners when there is traffic in front of you, which forces you to slow down and corner with a locked axle.
Apart from this it drives quite well, although there obviously are more elegant ($$) options than this.








Also did some more tuning. Engine is running around 120-130kPA of boost now. :nod:
Rev limiter is increased to 7100rpm with 200rpm soft limiter. (Was 6600)
In practice I shift at around 6600 rpm now, that's where the torque starts to fall off.
Some extra timing up top worked well.

An impression:

<iframe width="560" height="315" src="https://www.youtube.com/embed/xIOTqbNuafQ" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

Probably will be needing a new subframe and torque rods.
 
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Which exactly did you buy?


I am configuring myself a hose on https://www.probrake.de/Stahlflex-K...-Angaben-Sonderanfertigung-mit-TUeV-Gutachten

But i don't know which fitting to use on the other side of the banjo. Is it M12x1x17.5mm Thread?



Bled clutch: didn't work.

Realized it had to be the clutch line, as the throwout arm angle is correct.
Stock volvo clutch lines don't mix with stiffer PP's.
Installed this and bled clutch again:

hel-01.jpg


Clutch is rock solid now.
Drove the car. Already drives very well, even with modest timing.
Turbo spools well.
It hits "full boost" at 2600rpm (wg opens at 0.3 bar) :rofl:.
Already pulls well.

No leaks! I'm very satisfied. Time to start driving and tuning.
 
M12x1 as a movable, straight fitting or banjo suitable for M12 at the slave cylinder and a long fixed M12x1 at the bracket on the frame is the OE setup (at least on my '87).
 
For the bracket? About 24mm sounds about right.
On the ProBrakes link the fittings 553 (bracket) and 460 (slave) should be the same as the stock setup.
 
If you compare the both fittings, the 460 is 0,5mm shorter at the thread and the 551 is a fixed fitting. The length of the thread shouldn't make any difference at that point. The rest is the same.
With a lose fitting it's a bit easier to replace the slave cylinder afterwards, since you're able to disconnect the hose directly at the slave without touching the other side of the hose.
I have a custom HEL clutch hose on mine with the lose fitting at the slave and a fixed (but M10x1 + adapter, because they didn't have the M12) long fitting on top.
 
80 cm length, regular M12x1 banjo fittings on both ends.
Just use the supplied fittings and it will work perfectly.

<iframe width="560" height="315" src="https://www.youtube.com/embed/r5-DrSny7BE" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
 
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