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My 924 Turbo, up and running !
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Cédric  



Joined: 27 Aug 2004
Posts: 2015
Location: Sweden

PostPosted: Mon Aug 05, 2019 8:34 pm    Post subject: Reply with quote

Hi guys.

The corrosion we are talking about is the large grey area in the middle of the cylinder. Its definitely a re-bore as i can feel the irregularities in the cylinder wall. But I will run it as it is for now, just do the cylinder head.

I could actually measure blow by flow with the help from a blow by meter from work, they are pretty nice 0-5v units. Will start by hooking up the purolator outlet to a bottle and see how much oil carry over i get. There were some traces in the lower CIS unit (s2 routing), but nothing exessive.

I have a spare head, with some polished ports, new guides etc, but its in one million pieces, i think that head will hop on the new engine block when time comes. And then i can be more serious with recutting valve seats etc on that head.

Thanks for the offer about repackaing the ARPs, they really are much cheaper over there, i will dig around a bit regarding the shipping and i will come back. The cometic had a month lead time, so no stress

I would most likely not want to go to a fully flat piston, i might want to reduce squish area a little bit, but still want to retain a certain amount not to kill the combustion flame speed. this car needs driveability aswell, it wont be a boost monster 8:1 is probably a good level, i will go there now with the MLS i have ordered, so steppin down from 8:5, just to get a bit more margin.

I think Joakim and his 450hp engine uses JE pistons, but my memory is a bit hazy.
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Fasteddie313  



Joined: 29 Sep 2013
Posts: 2080
Location: MI

PostPosted: Tue Aug 06, 2019 1:42 am    Post subject: Reply with quote

The weak rim on the dished pistons disturbes me and I'd like to go non-interference if I could.. Machining a dish also sounds expensive, especially one that includes valve pockets, and then that sounds like a whole lot of math to figure out CR..

I don't even think they need to be light, just super strong and det resistant..

Car don't make no power when it ain't in boost anyway and doesn't rev either unless you want to do rods, pistons, lifter buckets, and maybe valve springs..

But I'm at 7.5:1 compression right now so that probably doesn't help much either..

How bad do you think loosing the squish area would really effect it?
The NA doesn't have any squish and makes 120HP with no boost..

You ever drive an NA? Do you think they have poor drivability due to no squish?
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chuck21401  



Joined: 20 Feb 2005
Posts: 283
Location: Annapolis, MD

PostPosted: Mon Sep 16, 2019 12:21 am    Post subject: Reply with quote

I have one of the AEM AFR gauges in my car.

I was reading the installation manual and looks like the gauge can be connected to a RS 232 (DB9) cable and then to a laptop. What else would I need? RS 232 to USB port adapter?

https://www.aemelectronics.com/files/instructions/30-4110%20Digital%20Wideband%20UEGO%20Gauge.pdf


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Cédric  



Joined: 27 Aug 2004
Posts: 2015
Location: Sweden

PostPosted: Wed Oct 09, 2019 8:14 pm    Post subject: Reply with quote

The head is finally back, they were very slow unfortunately. But now its skimmed, 4 of the valves didnt pass their seal test, so machined seats etc, new valve seals are in aswell (I found one of them in the sump as I mentioned before), and some other small stuff.

ARPs are in, Cometic MLS is here, to bad i hadnt ordered nuts bolts and gaskets, so that will have to wait until next week. The plan is to put it back as I took it out, with the manifolds and everything still attached.

Pic of cylinderhead with a link, sorry, i have better upload serivce at the moment..
[img]https://www.bildtagg.se/file/thumb/ebzlqv6mc9zo4cz06ms8himz[/img]
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safe  



Joined: 18 Mar 2017
Posts: 186
Location: Sweden

PostPosted: Wed Oct 09, 2019 9:00 pm    Post subject: Reply with quote

Cédric wrote:
The head is finally back, they were very slow unfortunately. But now its skimmed, 4 of the valves didnt pass their seal test, so machined seats etc, new valve seals are in aswell (I found one of them in the sump as I mentioned before), and some other small stuff.

ARPs are in, Cometic MLS is here, to bad i hadnt ordered nuts bolts and gaskets, so that will have to wait until next week. The plan is to put it back as I took it out, with the manifolds and everything still attached.

Pic of cylinderhead with a link, sorry, i have better upload serivce at the moment..
[img]https://www.bildtagg.se/file/thumb/ebzlqv6mc9zo4cz06ms8himz[/img]


I just read up on MLS gaskets. It seams it needs very flat and really nice and smooth surfaces.
Somewhere between "can't feel scratches with finger nails" and polished.
How have you prepped the block?
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Cédric  



Joined: 27 Aug 2004
Posts: 2015
Location: Sweden

PostPosted: Wed Oct 09, 2019 9:51 pm    Post subject: Reply with quote

safe wrote:
Cédric wrote:
The head is finally back, they were very slow unfortunately. But now its skimmed, 4 of the valves didnt pass their seal test, so machined seats etc, new valve seals are in aswell (I found one of them in the sump as I mentioned before), and some other small stuff.

ARPs are in, Cometic MLS is here, to bad i hadnt ordered nuts bolts and gaskets, so that will have to wait until next week. The plan is to put it back as I took it out, with the manifolds and everything still attached.

Pic of cylinderhead with a link, sorry, i have better upload serivce at the moment..
[img]https://www.bildtagg.se/file/thumb/ebzlqv6mc9zo4cz06ms8himz[/img]


I just read up on MLS gaskets. It seams it needs very flat and really nice and smooth surfaces.
Somewhere between "can't feel scratches with finger nails" and polished.
How have you prepped the block?


I havent done anything with the block, i just havent had the time/energy to even look at the surface. I will try to clean of the surface and see how it looks like. Ive heard both about the surface for MLS, some say its easy some says it needy. The block wont come out, so i will have to do with manual methods to get it good enough. Any recommendations on products or methods to get the old stuff of the surface?
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safe  



Joined: 18 Mar 2017
Posts: 186
Location: Sweden

PostPosted: Wed Oct 09, 2019 10:12 pm    Post subject: Reply with quote

Cédric wrote:
safe wrote:
Cédric wrote:
The head is finally back, they were very slow unfortunately. But now its skimmed, 4 of the valves didnt pass their seal test, so machined seats etc, new valve seals are in aswell (I found one of them in the sump as I mentioned before), and some other small stuff.

ARPs are in, Cometic MLS is here, to bad i hadnt ordered nuts bolts and gaskets, so that will have to wait until next week. The plan is to put it back as I took it out, with the manifolds and everything still attached.

Pic of cylinderhead with a link, sorry, i have better upload serivce at the moment..
[img]https://www.bildtagg.se/file/thumb/ebzlqv6mc9zo4cz06ms8himz[/img]


I just read up on MLS gaskets. It seams it needs very flat and really nice and smooth surfaces.
Somewhere between "can't feel scratches with finger nails" and polished.
How have you prepped the block?


I havent done anything with the block, i just havent had the time/energy to even look at the surface. I will try to clean of the surface and see how it looks like. Ive heard both about the surface for MLS, some say its easy some says it needy. The block wont come out, so i will have to do with manual methods to get it good enough. Any recommendations on products or methods to get the old stuff of the surface?


I was thinking of using a (new) whetstone to get it smooth, but if someone has a good solution how to not get crap down into the water and oil passages I'm all ear. Or another method al together...
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Carrera RSR  



Joined: 08 Jan 2010
Posts: 2051
Location: Somerset, UK

PostPosted: Thu Oct 10, 2019 4:44 am    Post subject: Reply with quote

I read that the MLS needed a 50 roughness average. I have no idea what that looked like. I asked my machine shop to deal with this. I hope they applied that surface treatment? Its survived since March 2015 through some tough asks of boost and some knock events. So it must of been OK?


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1980 931 - forged pistons, Piper cam, K27/26 3257 6.10 hybrid turbo, 951 FMIC, custom intake, Mittelmotor dizzy & cam pulley, H&S exhaust, GAZ Gold, Fuch'ed, Quaife
Now www.924board.org/viewtopic.php?t=34690
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Cédric  



Joined: 27 Aug 2004
Posts: 2015
Location: Sweden

PostPosted: Thu Dec 19, 2019 7:41 am    Post subject: Reply with quote

Since steve were mentioning dyno runs i tried a software i known for a long time but never used before. It uses rpm logs from road logging and car data to calculate acceleration. Pretty fun tool to use for tuning, especially if you use the same stretch of road allt the time it gets more accurate. to bad i had so much rpm glitches in the logs, so had little undisturbed ones to chose from.

Heres the high and low boost mode, only the high boost with sorted AFRs though.

Steve, can you export your logs in CSV? Could be an easy and fun way to compare our cars. Even though theres some guesstimations involved in the car data.



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Cédric  



Joined: 27 Aug 2004
Posts: 2015
Location: Sweden

PostPosted: Thu Dec 19, 2019 8:59 pm    Post subject: Reply with quote

FastEddie, you probably have massive amounts of logs? Do you have anything you can try in Virtual Dyno?

The blue 1 bar curve would probably be a bit higher if it was run in fourth gear just as the 0,7 bar run (red), which is in line with physics if you consider inertia effects and transmission losses.

Bottoming out forth gear on countryside roads is always challenging, and since i had problems with the RPM signal i had even fewer runs to chose from..
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Carrera RSR  



Joined: 08 Jan 2010
Posts: 2051
Location: Somerset, UK

PostPosted: Thu Dec 19, 2019 11:27 pm    Post subject: Reply with quote

There used to be an iPhone app called Dynolicious which I used a few times many years ago. I have searched App Store a few times for something similar based on internal G meter and GPS. Plenty of 0-60 and 1/4 mile acceleration apps. Tried one a few weeks ago and got several low 6.0 sec 0-60 but getting too much wheel spin in 1st and 2nd with damp ground and road tyres. I reckon I have a high 5.x sec something in the car on R tyres and dry road.

Cedric I will see what I have regarding logs pulled from the Zietronix box.
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1980 931 - forged pistons, Piper cam, K27/26 3257 6.10 hybrid turbo, 951 FMIC, custom intake, Mittelmotor dizzy & cam pulley, H&S exhaust, GAZ Gold, Fuch'ed, Quaife
Now www.924board.org/viewtopic.php?t=34690
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Fasteddie313  



Joined: 29 Sep 2013
Posts: 2080
Location: MI

PostPosted: Fri Dec 20, 2019 9:45 am    Post subject: Reply with quote



1791 (poorly coiled) hose powahs

First random log I loaded and told it that it was a jetta in 3rd or something.. Thought it was funny so I shared..


So uh..
I have no idea how to work this thing.. Can I email you a good log or something?
Or tell me your settings and how to cut chunks out of the logs?


???

Still not getting anything that seems right..
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Cédric  



Joined: 27 Aug 2004
Posts: 2015
Location: Sweden

PostPosted: Fri Dec 20, 2019 6:51 pm    Post subject: Reply with quote

Thats weird, i thought it was only supposed to use data where the TPS signal was 100%, that looks like the whole log. I have no TPS, so i cut out the fulload runs in logworks before i exported them and then I opened the CSV in excel and just added a TPS column withh 100% numbers in there. Naming is also important, you need to have correct names like TPS, AFR (or rename the channels in the options), at least if you run CSV files like i do.

Need to double check my gearing numbers though, i think I misstyped some of it.
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Cédric  



Joined: 27 Aug 2004
Posts: 2015
Location: Sweden

PostPosted: Tue Nov 24, 2020 6:49 pm    Post subject: Reply with quote

Testing imag links from another forum..





Krävs ungefär såhär många för att lyfta hela paketet på plats, en riktig bjässe till pjäs






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Mike9311  



Joined: 14 Dec 2004
Posts: 915
Location: Chicago-ish

PostPosted: Wed Nov 25, 2020 4:15 am    Post subject: Reply with quote

Nice to finally see larger photos. That is a nice 931!

Good idea too, to print the battery hold down. Had not thought of that idea

Who is the gymnast? I see the rings.

Edit: also neat to see an F body over there
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