924Board.org

[Josh931]

Hi, I'm the owner of a 82 series 2 931. I've had it for the past three years now, and in between studying I've manged to have a lot of fun with this car.
I've read a stupid amount of posts from this board. There is just so much good stuff available here, with most of the problems I've had with my car being discussed in detail, often with picture tutorials. Which has been great seeing as I do all the work on my car myself.

I initially started with just the basics of keeping the car running, with a few minor jobs such as replacing the battery bay as it was beginning to rust, and replacing a few vacuum hoses here and there, ect ect. It wasn't until recently that the tinkering bug bit hard!

I've installed a U-flow intercooler, similar to the unit that Morghen has installed in his car. The unit literally only just just fits in-front of the radiator, with the whole width of the cavity space available being utilized.
here is a picture of the unit.

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I used cardboard to check whether the unit would fit, such as in this image below:

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Getting the piping to run over the top of the dizzy was tricky, I lowered the dizzy by removing the rubber spacer units, and slightly altering the frame that it attaches to so that it could lie flat on the frame.
The piping I used was 2' aluminium from the turbo to just past the dizzy, it is then taken to 2 1/2' stainless steel piping to the intercooler. from the intercooler its a combination of aluminium and stainless steel. The aluminium piping running over the dizzy was squashed slightly to fit past the bonnet. The clearance past the bonnet is minimal. A lot of time and swearing was required to make the piping fit.
Here are a few images of the piping from different angels:
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For those of you who are worried about going with a FMIC because of the amount of piping required to make it work will increase lag, stop worrying and just do it! My system between the turbo and intercooler is made up of 5 90degree bends. with so many more going from the intercooler to the intake. instead of my turbo coming on at 2000rpm and reaching 10psi at 3000rpm it now comes on at 2100rpm and reaches 10psi at 3150 rpm. which is nothing! the time taken to go from 2000 to 2100rpm is nothing. The best way to reduce lag is to tune the car A/F ratio. I felt more gains in my car due to proper A/F than adding my intercooler.

The PO installed a stage 1 cooling mist methanol injection system in the car. I had removed the unit a while back due to the relay breaking and turning the pump on with the engine off.
But with the intercooler in I decided to reinstall the system, this time putting the relay inside the car with additional on-off switches. Here are images of the pump, solenoid valve (a feature I added to stop the solution seeping into the engine under vacuum, as a one-way valve aren't sufficient when the car goes into vacuum IMHO).The stainless steel canister on the shelf is used to contain the solution.

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I'm running standard 10PSI boost, I have the meth kit spraying just pure water atm, and I think the additional water to the system, even with ambient temp of 30+ degrees celcuis, is just to much and is drowning the spark. Any comments on this?

I installed a wide band O2 sensor and gauge. The gauge indicated that i was practically pouring fuel out the exhaust. However I couldn't correct the A/f for WOT conditions without destroying my idle A/F, the car would hardly run. So I installed a new WUR, the car performed better but the A/F was still rubbish and again I couldn't correct it to the point at which idle and off idle was nice and responsive whilst having correct boost A/F so I made up a CIS tester, and decided to make my old WUR 'three point' adjustable.
I tapped a screw into the bi-metallic strip pin allowing it to be moved up and down. I them drilled a hole through the brass stopper on the underside of the unit, to reveal the warm control pressure set screw. This doesn't need to be sealed after making the hole, it is a sealed compartment from teh rest of the unit. And then by tapping the brass stopper in a was able to decrease WOT boost enrichment. Because these measurements are all interlinked, I'd recommend tapping the enrichment stopper in first 1mm, and then hooking the CIS tester up and adjusting Cold pressure and then warm pressure. Here are images of how I did it:

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When I set the pressures, due to my car always tending to the richer side, I set the cold,warm pressures to the higher pressure limit within the specified range. Due to higher pressure meaning leaner mix. This worked well. My idle is at 12.9-13.9. Normal no boost driving is at 14.5 to 15, and then WOT 3500rpm is at 12. 4500rpm is at 11.5 5500rpmt is at 10.5. These figures are with the methanol injection off. Methanol injection richens it up.

I am currently struggling to find strut inserts. I can order struts but the import fee and tax is just ridiculous. I've replaced my strut bearings with golf mk1 bearing and the bush has been replaced with second hand 924 parts.
A few people talk about brass shift linkage bushes. Some are worried that this would cause unwanted vibrations. I got two brass bushes made up for a six pack of beer at my varsity workshop. There is no sloppy play in my shifter anymore, there are no abnormal vibrations being transferred down the shift linkage. They are easy to make and cheap and will never need replacing again! here are images of mine.

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Changing the linkage must have been the hardest job I've done in this car! I listened to someones advice who said it can be replaced with the tranny in place, NEVER AGAIN! it was hell to get out and worse putting it back!
I won't lie, but everything on this car has been a mission! Even just changing the dif oil required that I got a special tool made because allen keys don't fit, allen sockets don't fit and I couldn't just use a bolt with two lock nuts as the PO tightened the sump plug to the point that I broke a few of the home made tools before it came loose.

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I have done countless small jobs to get the car looking how it does, and there are still heaps more to do!

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What car would be complete without a sound system to match.

This image shows the tweeter and the green meth injection LED indicator light
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6x9s in the wheel wells
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good little 12' flat line sub, its the only sub that will fit in the shallow boot.


And then a hidden 4 channel amp to power it
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I am running stock boost for two reasons. 1) This car is already insanely quick! 2) why mess with an old engine if its pulling awesomely already!
I'd just like to thank everyone from this board for helping with my project and then special thanks to Morghen who has gotten main frantic emails because my car was acting up.

I've got a question for the boffs. How loud should the pop-off valve on our turbos be? When i start the car and if i blip the throttle or come off the throttle there is a loud clunk, I'm 80% sure its my pop-off valve. I am not down on power so i don't understand why its so noisy as its clearly working. hhhm now that I think about it maybe its an engin[/img][img]e mount?

Thanks
Josh[/img][img][/img][img][/img]
_________________
1990 Suzuki J410 sold
1985 Alfa Romeo 2.L GTV sold
1992 Honda VFR400 written off
1980 Porsche 931 going strong,,,well sort of

[morghen]

Lound clunk is ok, you should be able to hear it from the driver's position with open windows but not or barely with the windows closed. Thats how mine sounded before i replaced it with a larger K27 hybrid.

Your intercooler setup looks better than mine !
Congrats, it looks like a nice car !
_________________
https://www.the924.com

[Josh931]

Sometimes, not to often, when I start my car, the revs will hang around 1800rpm, and then there is the loud thunk, and the revs drop back down to 1200rpm. I never noticed the thunk sound when i got the car, that makes me think its gotten louder.
Here is a picture of the whole current engine bay. The exhaust wrapping makes a massive difference for heat soak from standing still in traffic. It may keep in heat, but I'd rather keep in a small portion of the heat that wasn't removed by the intercooler then take in heat from the hotter exhaust manifold. (heat travels from high to low).
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_________________
1990 Suzuki J410 sold
1985 Alfa Romeo 2.L GTV sold
1992 Honda VFR400 written off
1980 Porsche 931 going strong,,,well sort of

[Josh931]

Anyone experience problems running both an intercooler and water injection at standard 10PSI boost? Water injection comes on at 10PSI.
_________________
1990 Suzuki J410 sold
1985 Alfa Romeo 2.L GTV sold
1992 Honda VFR400 written off
1980 Porsche 931 going strong,,,well sort of