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supercharger conversion pictures
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leadfoot  



Joined: 11 Dec 2002
Posts: 2222
Location: gOLD cOAST Australia

PostPosted: Sun Apr 17, 2005 1:41 pm    Post subject: supercharger conversion pictures Reply with quote

Here some pictures of my project to date.
The blower has been installed, it is a SC12 from a MR2/4AGZE engine and retains the magnetic clutch and vent lines for the gear housing, both are operated off the same relay.
The SC mounts are made from 5mm steel, the front mounts off the three bolt tang where the air con mounts(removed previously) this is at a horizontal line and the blower mounts at 45 degrees, a top mount supports the top off the blower and attaches to the manifold where the triangular manifold to block support used to be. I also made an engine damper that is attached off the bottom of the blower to the crossmember, this dramatical reduces engine and accelerator pedal vibration, my car never had the factory damper or provisions for mounting them.
Custom inlet and outlets have been made from aluminium, with all other piping to/from the intercooler being 2.5".
The SC is set to come on at 1400RPM and .4% throttle, the throttle positioning is due to balancing the airflow through the air bypass solenoid and to make idle easy to tune. It also is set to come on after the engine has warmed up , around 65 degrees.
It is currently running 3psi at the manifold through a WRX 97/98 intercooler. The intercooler is a top mount modified so that airflow is reversed and the dual outlet is now running a single 63mm intake from the side.
A 3" diameter plenum mount was made by me to mount the ford XF throttle off, this also caters for the air bypass solenoid form a ford XF. In hindsight a smaller throttle would have been better suited and due to the tight curves 2.5" tubing could have been used.
Compression is standard 9.3:1 euro pistons with standard block/rods etc... cylinder head has been P+P'd and a modified cam installed with the stats:
Cam lift EX & IN .459"
Adv Duration EX & IN 274 degrees
Duration @ .050" EX & IN 233 degrees
Valve Lift EX & IN .449"
Lift @ TDC No 1 EX .074" No 1 IN .069"
Phase angle 110 Degrees
Timing EO 68 EC 26 IO 28 IC 66
I need to have another aluminium crank pulley made up as my inital calculations could not fully take into account the efficiency of either my engine or the blower, I actually overated these figures and the 130mm pulley will see a 20mm diameter increase in size and yield around another 3 to 4 psi. This new crank pulley will also be set up will a trigger wheel to run distributorless ignition.
The old pulley will be made available to someone who wants to run a similar system without an intercooler and will make aound the 3 to 5 psi mark with and SC12 slightly higher if you get the later model blower that had the 5mm smaller pulley, there is also an aftermaket blower pulley that would be another 5mm smaller again but a new stator is required. If used with the SC14 higher psi would also be achieved.
There has been no increase in intake temps at the moment, due to the low psi figures, yet it was suprising to see this as the SC12 is aparantly one of the worst for efficiency.
The engine has been dyno at just over 140hp at present and its weight is near the 1000kg mark. The low end before the install was a little soft with this cam profile but now is fantastic. The throttle response is also so sharp that it will take getting used to. A smaller throttle would have been better suited to the travel of the clutch pedal. This change will be made in the future with a modified plenum, the runners would be cut at their ends and a 3 litre plenum made from a 100mm diameter X 300mm length of aluminium tube. This will house a smaller throttle and give a more direct path from the intercooler.
I still need to make an intake mount for the air filter and this will be directed behind the headlight. All the headlight raiing mechanism has been retained.
Leadfoot












Dyno results fom EFI tuning
62 RWKw X 1.3410 = 83.142HP X 1.42 (30%) for driveline loss = 118.06HP Flywheel Approx

Dyno results after blower install
74 RWKw X 1.3410 = 99.234HP X 1.42 (30%) for driveline loss = 140.91HP Flywheel Approx


Last edited by leadfoot on Sun Apr 17, 2005 4:51 pm; edited 3 times in total
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ideola  



Joined: 01 Oct 2004
Posts: 15515
Location: Woodstock IL

PostPosted: Sun Apr 17, 2005 2:32 pm    Post subject: Reply with quote

That looks COOL! Very impressive.
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15 981 GTS | 88 924S SE | 82 931 Holbert | 82 931 Rallye | 81 937 | 81 Euro 931 | 81 Weissach | 80 US 928 | 80 US 931 '941' | 80 US 931 | 80 931 GTR | 79 Sebring | 78 D-Prod Replica | 78 w/D-Prod kit | 78 Poli-Form | 78 Limited Edition | 77 Martini
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Lizard  



Joined: 03 Nov 2002
Posts: 9379
Location: Abbotsford BC. Canada

PostPosted: Sun Apr 17, 2005 3:57 pm    Post subject: Reply with quote

I like now for some dyno #'s
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3 928s,
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leadfoot  



Joined: 11 Dec 2002
Posts: 2222
Location: gOLD cOAST Australia

PostPosted: Sun Apr 17, 2005 5:14 pm    Post subject: Reply with quote

There you go Lizard... If my figures are correct, the torque has increased from 135 lb ft to around 200 lb ft.... but dont quote me on that as i'm assuming the N is in newton meters, this should increse with the new pully but I don't think I'll get it dynoed again until I get the new intake made. This will be done at a later date when I have the bottom end serviced.
Right now I'm going to get back to driving and enjying my handywork.
Leadfoot
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Lizard  



Joined: 03 Nov 2002
Posts: 9379
Location: Abbotsford BC. Canada

PostPosted: Sun Apr 17, 2005 6:06 pm    Post subject: Reply with quote

it looks awsome,

I agree with the driving of your car, while driving my 928 I am going to be hopefully fabbing up a twin turbo setup for it and hoping to break the 500 RWHP (corrected) mark, but only time will tell
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J1NX3D  



Joined: 06 Feb 2003
Posts: 1332
Location: New Zealand

PostPosted: Sun Apr 17, 2005 9:32 pm    Post subject: Reply with quote

man that looks great! impressive work!
what kind of power estimate do you think you had before you started everything- before the efi and s/c?
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maireeka  



Joined: 29 Aug 2004
Posts: 300
Location: North Alabama

PostPosted: Sun Apr 17, 2005 11:53 pm    Post subject: Reply with quote

very nice! what kind of boost can the block handle?
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leadfoot  



Joined: 11 Dec 2002
Posts: 2222
Location: gOLD cOAST Australia

PostPosted: Mon Apr 18, 2005 12:23 am    Post subject: Reply with quote

I had the car running really well before the efi conversion, it was not as responsive in the throttle but the maximum power was about the same, mabye 5Kw was picked up in the mid/high end after the conversion. With my cam it didn't help the low end torque that much.
I wouldn't expect anything more from efi, efi makes the car as good as it can flow naturally, which with these cars is not the best. The major benefits are the programmable igniton curve and the cleaner throttle response, plus you get the little benefits like, cheaper fuel pump relay, thermofan control, security PIN imobilisation and a neater engine bay. Fuel economy was around the same.
I still believe stroking, a larger bore or higher compression pistons or all of the above are the way to go on an N/A to achieve good HP figures.
Leadfoot
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endwrench  



Joined: 07 Dec 2002
Posts: 1629
Location: Victor, Montana

PostPosted: Mon Apr 18, 2005 4:13 am    Post subject: Reply with quote

Yea Baby!!!! NICE!!!!!!!!!! You are way ahead of me at this point. Pretty cool to see. I didn't even know you were working on this! I will be studying the pictures and will have plenty of questions later. For now, just give yourself a well deserved pat on the back!!

Todd
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'79 924NA. Rebuilt 9.5:1, MSDS header, Mega Squirt Injection, MJLJ-EDIS Ignition, 1.6L Whipple Charger and Intercooler, 10lbs Boost, 944 Trans, Custom HD Clutch.
"simsport" said....superchargers are better than turbos its official!....
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endwrench  



Joined: 07 Dec 2002
Posts: 1629
Location: Victor, Montana

PostPosted: Mon Apr 18, 2005 3:56 pm    Post subject: Reply with quote

OK, some questions,

1: How big is your throttle body? I don't know what an XF is

2: What injection system are you using?

3: What size is the pulley on the charger?

4: Are you building the new pulley from steel of aluminum? Do you have the dimensions for the V-grooves? I believe they are 40 and .140" on center but I don't know for sure. I am getting ready to cut mine and I would like to know before I do.

5: Did you use Corky Bells mathmatical figures for your initial try at pulley size estimating?

6: What is the capacity of the blower you are using (i.e. 45cid or 1.2L etc.).

More brain picking later

Todd
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endwrench  



Joined: 07 Dec 2002
Posts: 1629
Location: Victor, Montana

PostPosted: Fri Apr 22, 2005 3:02 pm    Post subject: Reply with quote

Another question. Why are you going to a 3 litre plenum? I was of the understanding that a plenum matched to your engine size was optimum. What have you read?

Todd
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Khal  



Joined: 26 Sep 2003
Posts: 4866
Location: Snowy but pleasant interior BC, Canada

PostPosted: Fri Apr 22, 2005 7:29 pm    Post subject: Reply with quote

How to tell someone's not Australian;

endwrench wrote:
I don't know what an XF is...




This is an XF...



Spec's for the most common model (they came in 200ci and 250ci) can be found here.
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endwrench  



Joined: 07 Dec 2002
Posts: 1629
Location: Victor, Montana

PostPosted: Sat Apr 23, 2005 2:17 am    Post subject: Reply with quote

Man, why do you guys get all the fun rear drive cars?

Thanks for the info.

Todd
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leadfoot  



Joined: 11 Dec 2002
Posts: 2222
Location: gOLD cOAST Australia

PostPosted: Sat Apr 23, 2005 3:34 pm    Post subject: Reply with quote

Nice picture Khal, going to give it to my girlfriend... she's a ford gal at heart, I keep telling her to trade in the panel van and buy a GT40... needless to say it hasn't happend yet....

the XF throttle is 68mm, I sugesst something around 55 - 60mm would be better suited. It's for low throttle smoothness, stops the car from wanting to launch off the line. Might make it a little easier on the cars clutch too.
The XF are plentiful and cheap. These body's are quite long though and another option would be a ford explorer unit which is also 68mm or going with a 944 throttle which is around the same size length but a smaller throttle plate from what I remember, I'll have to dig up one of my previous posts as i did have someone measure the 944 throttle for me. The XF unit I got was around a quarter of the cost of a second hand 944 throttle, but again it's off a 4 litre engine.

Ignition is a Wolf 3D version 4 ECU, injectors are bosche 300cc 14mmB29/58/2.5H . Standard distributor with the flyweights welded. A new bosche 024 ignition module was used with a replacment coil, tach signal is still generated from the negative side of the coil ( standard coil could be used though) I replaced mine because it was the origional part.

Pulley sizes are 115mm supercharger crank 130mm

I will be getting someone else to make up a new crank pulley out of aluminium. Groves are a standard size to run a 5 rib pulley. No fancy stuff required here, just match it to your whipple pulley. As for angles I'm not sure exactly, might need to do some research there.

Yes initial sizing was done mathematically with a couple of different sources including corky's book. Three things I couln't accomodate in my equations were ; the VE of my engine, the VE of the blower and pressure drop through the intercooler and piping. With 3 psi at the manifold my new sizing will be made at 165mm. This should raise max psi to around 7
What I found was about a 70% correction to my calculation was needed after calculating pressure ratio vs airflow of blower. This might seem like alot but considering that it is a roots type blower and efficinecy in these can be as little as 35 % until they get up to speed a 70% correction including VE of the engine doesn't seem so unusual.

Capacity of the blower is 1200cc or 73ci

Plenum size needs to be ...at least the engine displacement... So around 3 ltrs would be a better option. This site http://www.sdsefi.com/techinta.htm recomends 3" tubing for 1600cc engines and 4" tubing for engines above.
If your making it out of aluminium then its going to be 80mm or 100mm tubing as the next sixe down is 63mm.
The length needs to be slightly longer than the head for better end cyclinder filling and therfore;
80mm tubing X 40cm length = 2.01 litres
100mm tubing X 40cm length = 3.14 litres
I think the 100mm tubing would be the better chioce with shorter runners for high RPM torque or longer suited to low end rpm torque.
As for throttle placement well there are many factors... shortest route from intercooler, even cylinder filling and space requirments are all factors. If you were to be running no intercooler then a twin throttle coming dierctly from the SC outlet into the side of the maifold would be a good idea.
Seeing as you are running an intercooler the a front mounted throttle would be logical with slightly shorter runners for low to mid rpm range with velocity stacks incorporated into the design. This should accomodate for the number 4 cylinder getting enough air to it and also improve the airflow reported to be up to 25% better.
As you would see mine is running in the stock location, this was mainly due to time constraints. I drive the car daily as well and so until the manifold is in place no oulet tubing could be constructed for the intercooler.
With what I've learnt from the project so far I will be able to get the rest constructed and essentially plug and play install the new parts (manifold / throttle).
Also in regard to the throttle, for a blow through arrangment such as mine you want all the ports to be blocked. I am running with one open for an air bypass solenoid (also of an XF falcon) that runs around the throttle.
This is only for warm up operation and runs essentially closed after reaching a set temperature. The are a little hard to tune when warming up as the boost can give the solenoid a hard time trying to close but if you reverse the input for the output it works better (go figure that one out).
This has more to do with the response time when cold though, as it has to open really quickly when off boost (sc is clutch operated at 1400 rpm) in order for the car not to stall. The difference in travel time reduces once the car warms up. My car requires alot of flow when cold and very little when warm.

Hope this answers your questions.
Leadfoot
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endwrench  



Joined: 07 Dec 2002
Posts: 1629
Location: Victor, Montana

PostPosted: Thu Apr 28, 2005 10:54 am    Post subject: Reply with quote

So you're using programable ignition. Did you have to dial in any retard yet with your current setup? Do you think you will with higher boost?

With your current setup, at what RPM do you start building boost and at what RPM do you reach a full 3lbs? I ask this because one of my biggest concerns is building boost down low. I have such a large compressor I can't turn it too fast without building too much boost. Seeing what your setup does between pulley changes will help me gauge my own setup. Purely for driveability and ease of installation I like yours better than mine! The use of high compression and low boost seems like a winner if all works out well. I'll be installing a 931 head at the time of my blower installation along with another set of pistons to bring my compression up to something reasonable.

Todd
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