'73 Resto & Suby 6 Conversion, or a primer on "How to convert your 914 to a Subaru 3.0" Options

[rnellums]

I Haven't noticed the front end getting light from venting through the floor, but I'll let you know after my track day this weekend (i should be hitting 115 mph easily). I have noticed that I seem to run out of gear though with stock profile tires. At 105-110 I seem to be getting pretty close to the redline in 5th. I've got my prototype front ducting setup now and essentially have a full front trunk worth of space (spare in trunk).

[madmax914]

I Haven't noticed the front end getting light from venting through the floor, but I'll let you know after my track day this weekend (i should be hitting 115 mph easily). I have noticed that I seem to run out of gear though with stock profile tires. At 105-110 I seem to be getting pretty close to the redline in 5th. I've got my prototype front ducting setup now and essentially have a full front trunk worth of space (spare in trunk).

I'll be eager to hear how it does for you this weekend. Do you have any pictures of your front trunk set-up?

Thanks,

[mgp4591]

I noticed my Subie is out of revs around 118 or so- sounds like you have the same trans as mine. And yes, pictures please! Seeing your setup gave me lots of ideas and now you've run out of room?! (IMG:style_emoticons/default/idea.gif)

[DBCooper]

I'm surprised you're all done so soon. I've been told my car goes... um... quite a lot faster than that, and I know was still pulling very hard at 109 in the quarter.

[BIGKAT_83]

I Haven't noticed the front end getting light from venting through the floor, but I'll let you know after my track day this weekend (i should be hitting 115 mph easily). I have noticed that I seem to run out of gear though with stock profile tires. At 105-110 I seem to be getting pretty close to the redline in 5th. I've got my prototype front ducting setup now and essentially have a full front trunk worth of space (spare in trunk).

Using the stock ECU what is the rev limiter set at? I have my Megasquirt set for a soft limit at 7K.

[rnellums]

THe stock EZ30D is at 6500 RMP. It is still pulling hard headed towards redline. The transmission is out of a 2001 2.5 RS (final drive is 4.11) which I believe has the tallest gears. I could always go to a larger profile tire. I'll update some pics of my front trunk in my thread tonight.

[76-914]

I'm glad this came up. I will need some new tires to replace these 10 yr old's. I'd like taller tires to improve the usefulness of 1st gear. What tall tires sound good. I'm running 4 bolt wheels so I might be limited. Suggestions?

[ruby914]

I'm glad this came up. I will need some new tires to replace these 10 yr old's. I'd like taller tires to improve the usefulness of 1st gear. What tall tires sound good. I'm running 4 bolt wheels so I might be limited. Suggestions?

4 bolt wheels, tall tires sound good (IMG:style_emoticons/default/happy11.gif)
So, you thought you were all done? (IMG:style_emoticons/default/shades.gif) (IMG:style_emoticons/default/lol-2.gif) (IMG:style_emoticons/default/av-943.gif)

[euro911]

See if you can get some 205/65x15s ... you may need to roll the rear fender lips though (IMG:style_emoticons/default/confused24.gif)

[ruby914]

Before I flared my car, my current front tires (225 x 50 x 16) were in the back.
It took a lot of rolling but I really did like the look. They were 5 lug but you can fit quit a bit in the back before you have to flare.
With the original 4 lug wheel and tires, I remember a lot of tire spin. With the 6 and no turbo, how does it feel now?

[76-914]

I'm glad this came up. I will need some new tires to replace these 10 yr old's. I'd like taller tires to improve the usefulness of 1st gear. What tall tires sound good. I'm running 4 bolt wheels so I might be limited. Suggestions?

4 bolt wheels, tall tires sound good (IMG:style_emoticons/default/happy11.gif)
So, you thought you were all done? (IMG:style_emoticons/default/shades.gif) (IMG:style_emoticons/default/lol-2.gif) (IMG:style_emoticons/default/av-943.gif)

I always planned on keeping the 4 bolt wheel pattern. It's part of the "bait". (IMG:style_emoticons/default/happy11.gif)

See if you can get some 205/65x15s ... you may need to roll the rear fender lips though (IMG:style_emoticons/default/confused24.gif)

I'm running 205/60/15's currently. Embarrassed to say but I never learned the new tire sizing thing. What exactly is the difference between the two, Mark?

Before I flared my car, my current front tires (225 x 50 x 16) were in the back.
It took a lot of rolling but I really did like the look. They were 5 lug but you can fit quit a bit in the back before you have to flare.
With the original 4 lug wheel and tires, I remember a lot of tire spin. With the 6 and no turbo, how does it feel now?

I don't have that info yet Mike. No tire spins until I can magnaflux my home made engine cradle. That will be another 30 hr's TT from now. But to answer your question, I'm pretty sure it will spin anything I can bolt to my current set up. (IMG:style_emoticons/default/happy11.gif)

[euro911]

My understanding was that you were planning on stock offset wheels and retaining the narrow body characteristics. That's why I said 205/65-15s. I apologize if I'm preaching to the choir, but here goes:

The first # (205) is the tread width (the higher the #, the wider the tire is). In this case, a 205 is a nominal 8" width.

The second # (65) is the aspect ratio, or 'profile' (the higher the # the taller the tire is).


The stock OEM 914 tires were 165SR15, which were actually 165/80-15 (6.5" wide and 25.4" diameter). 205/65-15s are only slightly taller (25.5" diameter) than the stock tires but 1.5" wider (8").

205/65-15s are roughly 3% taller than the 205/60s you're currently running, so they're pretty close to stock height.

You can get away with wider tires (maybe 215) if you have a lower profile, but you may have rubbing issues, especially during hard cornering at speed. Also, the lower the aspect ratio, the higher RPM you're running at highway speeds.


Here's the tire size calculator I've been using for years: (Tacoma World Tire Size Calculator) ... There's also one on 914 World as well, but I haven't been able to get it to work for me (IMG:style_emoticons/default/confused24.gif) ... (Click here)

[Chris H.]

205/65 would be pretty fat and wide, I might be worried about rubbing (that's the weirdest thing I have typed in a while). 195/65 is very close to the original (tall) stock. Every brand is different though so check a few out unmounted before you get them installed.

Speaking of louvers (IMG:style_emoticons/default/piratenanner.gif)

Check out what I got done today:

oooohhh



aaaaahhh



other noises




Found the NICEST guy who punched some more louvers in my PM panel. He owns a one-man hot rod shop about 50 miles outside of the Chicago area (but 100 miles from me). Was doing some beautiful cars. All 1920's to 1940's stuff. His metal skills were amazing. Of course I left my phone in the car so no pics there (IMG:style_emoticons/default/headbang.gif) . Went from 16 to 40 total in a ~ 12.5 inch x 18 inch area. I also like the fact that the more concentrated ones are towards the back where most of the air will be exiting.

He said he would be willing to do more panels so maybe I'll do a group thing if there's a demand. Could probably do it for not much more than a Patrick panel but with about 3X the louvers.

OK Kent, I have 40, 4" x .25" louvers, what's my total exit flow area now? Am I at 2:1 if I cut the front out like yours but maybe not the upper bumper part? Just cut the holes into one big hole?

Edit: Duh, it's 40 square inches...I'll measure the inlet...probably NOT 2:1 but if I shroud it hopefully we'll be OK.

[76-914]

That panel gives you ~40sq inches. If your cut out is like mine (3.5" x 18") your inlet will equal 63". I've read but not confirmed that our target area for the outlet should = 1.7 x the inlet area.
63 x 1.7 = ~107 sq inches.
-40 sq inches
67 sq inches
So, if that 1.7 factor is correct you'll need another 67 sq inches. That being said, there are at least 5 unknowns that come to mind. First, is 1.7 factor an arbitrary number reached by someone? Was that figure for a LS1, 350 CI block, a 4 cyl Suby, a Ford 6 cylinder and so on? Where was that person's inlet and outlets located? What effect does hose size or routing have on this formula? Secondly is the location/placement of the outlets/louvers. IOW, are we placing the louvers in the lowest pressure area? The style of bumper that we use will greatly effect this location as well. I would think the louvers are most effective close behind the bumper where they ride in an relatively undisturbed slipstream. I suspect the air becomes quite scattered the further back one goes, which I'm sure has it's effect upon how efficient these louvers will be.
FWIW my total outlet area = 61 sq inches. So by following that formula I am 46 sq inches short or appx 43% undersized. As you know (Chris and I compare notes on a very regular basis), I'm very close, if not "at" the correct amount.
Alas, we may all be on our own until we standardize these installations and I don't see that happening unless people are willing to duplicate someones "correct" build.
I wish one of our AE's here was water cooled and could put the slide rule to this. A wind tunnel or raised flat bed truck + a 914 + some streamers and smoke pens would give the visual reference that my dumb ass would need. (IMG:style_emoticons/default/biggrin.gif)

[Chris H.]

Well I'm not sure if this will be enough but I'm planning to start by just cutting the holes up front into one big hole, so that's 2x18". Gives me 36 square in, 40 square out. If that proves to be inadequate I can cut out a section of the inner part of the bumper reinforcements. Definitely can get to 2:1 that way. I ordered the Renegade valance that looks like it scoops air in pretty well and then plan to make a ducting system like Ross's to push it back out. I think it will work fine.

[76-914]

I like it! Looks like that shape will give you a nice low pressure area beneath the louvers, also. (IMG:style_emoticons/default/popcorn[1].gif)

[Chris H.]

Yeah I called in last week to order it and the VERY nice person on the phone said "Hi this is Melba! How can I help you????" I thought...Melba...how do I know that name....hmmmm...don't know anyone who lives in Vegas....after a while I realized it was Toast from the BBS! Too funny.

[76-914]

Toast is good people. (IMG:style_emoticons/default/grouphug.gif) Well, my Speedo died yesterday but no biggie. It's new. I had done a quick patchwork at the gage area that needed to be corrected. I wired in a 12v power outlet but it's not installed on the gage face plate yet. The CEL is also back there and waiting to be installed. Obviously I need to make another piece of the burled aluminum for the base plate. It will glue on the piece of plywood with a new shift boot. Use your imagination! Outside of the Burled Aluminum trim, it came out remarkably stock in appearance which is exactly what I had wanted. (IMG:style_emoticons/default/smash.gif)
Gone are the A/F gage, oil pressure gage, fuel pressure gage. One vacancy will be filled with the seat heater switches another with a courtesy lite and the 3rd hole with the 12v power receptacle. All of my ancient carpet was rejuvenated for $13 worth of Dupli Color Vinyl, Fabric and Carpet spray paint. Doesn't leave the carpet feeling stiff either. (IMG:style_emoticons/default/smile.gif) It does require vacuuming just like regular carpet though. (IMG:style_emoticons/default/headbang.gif) Anybody notice the missing radio? Not me. I can listen to that 6 all day long. (IMG:style_emoticons/default/wub.gif) The stereo is last on my list.

[76-914]

My fans are now working off the ecu but I'll be damned if I know why. Let me go back to the beginning. I've always been mindful of over heating the engine so I let the engine get to 3/4 (on the factory gage) of the way HOT (normal is 1/2) and I would check each of the 3 wires coming from the ECU for continuity. They provide the ground to the relay that controls that fan. I never got continuity on any wire or any combination of those 3 wires. (IMG:style_emoticons/default/WTF.gif) Last week after some testing I forgot to remove the jumper that ran from the low speed wire to the 3 wires twisted together. (Previously I had jumped the low speed wire to ground when needed. Which was when I saw temps climb past 1/2 way on the gage.) Anyway I came home and thought I heard the fans spooling down when I shut it off. (IMG:style_emoticons/default/WTF.gif) Turned the key back on and nothing. OK, I was hearing things. Next nite same thing so I made a note to check the fans before shutting it down the next day. Sure enough the next day I pull into the garage and with the engine running I feel air sucking in the inlet. Pop the hood and the fans are running. And within 30 seconds they shut down and gage was below 1/2. (IMG:style_emoticons/default/WTF.gif)
For the life of me I cannot explain this sequence. Possibly the ECU looks at that connection before needing it and writes it off if it's not there. And why would it not connect after temps went passed 1/2 (IMG:style_emoticons/default/confused24.gif) And to confuse matters further, guess when the fans come on? At the 1/2 mark! Way cooler than I expected. I never thought to check for signals at that temp. As long as they work and the engine is happy, I'm good. In the coming weeks I plan to delete 1 wire at a time from the bunch of 3 to determine what does what. I suspect 1 wire will be common to the other 2 and those 2 will be hi & lo. Well see. (IMG:style_emoticons/default/dry.gif) 700+ miles and counting. (IMG:style_emoticons/default/biggrin.gif)

[Chris H.]

Sure enough the next day I pull into the garage and with the engine running I feel air sucking in the inlet. Pop the hood and the fans are running. And within 30 seconds they shut down and gage was below 1/2. (IMG:style_emoticons/default/WTF.gif)

Sounds like your airflow is pretty good! (IMG:style_emoticons/default/beerchug.gif)