Tracking the 914 - Happy New Year!, Turning this into a regular thing... Options

[infraredcalvin]

I’m hearing you about running rich. I’m still getting into the 10s at WOT, track is 1500 ft higher in elevation than my house, so rich here is going to be really rich there. I may try downsizing mains and idles one more time, see where that gets me. These afr gauges are a godsend and a curse, in the search for perfect AFRs.

As for driving there, well not yet, a uhaul will work fine, it’s easier to drop the car at the track and not worry about it in a hotel parking lot.

[Justinp71]

Wow, 10:1 at WOT that is rich, got some power on the table there...

You may want to consider a more open yet still combining exhaust. Knight racing talked me into a single magnaflow 2x2 muffler. If you're looking for more power, that should help lean it out too.

Some cool dyno tuning info on this thread plus the picture of the muffler setup, this guy also happened to talk to knight racing. 253 WHP from a street 3.2-
http://forums.pelicanparts.com/porsche-911...fore-after.html

[Charles Freeborn]

Wow, 10:1 at WOT that is rich, got some power on the table there...

You may want to consider a more open yet still combining exhaust. Knight racing talked me into a single magnaflow 2x2 muffler. If you're looking for more power, that should help lean it out too.

Some cool dyno tuning info on this thread plus the picture of the muffler setup, this guy also happened to talk to knight racing. 253 WHP from a street 3.2-
http://forums.pelicanparts.com/porsche-911...fore-after.html

Try going up a size on air correction jets too.

[infraredcalvin]

No videos or real pics, but Willow Spring's was a bit humbling for me last weekend. Car needs A LOT of dialing in.

Motor ran fine, but I feel I'm missing 50-75 horses somewhere in the tune. Chatted with a few shops that were there, looks like it'll be headed to AASE shortly for a test and tune.

I was really uncomfortable in the car, seat too high, wheel too close, shifting with the Vellios 915 is vague a best. Enough with the excuses, but I was 8 seconds quicker per lap in the old car... huh go figure...

At least I now have a baseline and can start tweaking to make it mine!

[infraredcalvin]

Arrived at track!

[Justinp71]

Nice! I'm sure you'll be knocking the seconds down with getting it tuned in!

How do you feel with your suspension? Able to carry a lot of speed thru the turns?

Might be able to keep it in the taller gear thru a turn to gain time if shifting is real slow, that big 6 will just push thru. I've done this in other cars and been faster.

Are you still 10:1 AFR at WOT? That will hurt power. Also if you don't already have it consider combining your exhaust outlets. Timing would be another good area to check.

I am thinking of going with a kirkey seat next to gain headroom, probably direct mount.

[infraredcalvin]

Right now engine tune is my highest priority, yes as I glanced down I could see the AFRs creeping into single digits, so it’s stabilizing in the low 10s. The motor seems really slow to rev, like it’s running out of breath... possibly a timing issue. I found some old dyno sheets in some of the piles of stuff that came with the car, it was showing high 160s to the wheels. Im not sure if it’s the dyno for this motor as it seems really low for what I’m told is in this car, I think it should be well over 225 if not 250 at the wheels. But right now my butt is saying it might be true, could it eally be off close to 100 hp??? sounds like wishful thinking... we’ll see.

Regardless, torque is nice enough to hold tail to the ground, it spins slow, running out of steam around 5k - maybe cam choice? Lots of variables, that’s why I’ve got an appt set up with experts, want to be sure I’m maxing out what I have before changing expensive motor parts out.

As for handling, cars seems neutral, seems like I could hold much more though the corners with new tires, the old r888 are really unpredictable on this car, due to sizes I’m looking at yoko a052, hear they are the best for 200 tw at the moment...re71s don’t come big enough for 16 in rims. And my pocket can’t afford Hoosiers yet...

As for seat, yes, need to get it on the floor. I’m not a fan of any aluminum seats, watched a fellow racer get trapped cause the al seat clamshelled around his body, and he couldn’t get out without help prying the seat open. thankfully no fire, but it was a scary moment for sure. Lots of people run them, and this was prob a fluke, but made the decision to stay away since then.

I got my Recaros on the floor in the old car by taking out the cross support, it gave me almost 2 more inches clearance. I don’t want to do that in my 6, so I’ll have to come up with something else, but an inch would be a huge help.

[infraredcalvin]

Gotta pin down front of hood. PO put spacers at the rear of hood, prob to let all this air out from the nose...sheesh it’s like a parachute! I now know why the factory has 4 pins on the nose (mine only has 2 just behind the light buckets).

[wndsrfr]

Right now engine tune is my highest priority, yes as I glanced down I could see the AFRs creeping into single digits, so it’s stabilizing in the low 10s. The motor seems really slow to rev, like it’s running out of breath... possibly a timing issue. I found some old dyno sheets in some of the piles of stuff that came with the car, it was showing high 160s to the wheels. Im not sure if it’s the dyno for this motor as it seems really low for what I’m told is in this car, I think it should be well over 225 if not 250 at the wheels. But right now my butt is saying it might be true, could it eally be off close to 100 hp??? sounds like wishful thinking... we’ll see.

Regardless, torque is nice enough to hold tail to the ground, it spins slow, running out of steam around 5k - maybe cam choice? Lots of variables, that’s why I’ve got an appt set up with experts, want to be sure I’m maxing out what I have before changing expensive motor parts out.

As for handling, cars seems neutral, seems like I could hold much more though the corners with new tires, the old r888 are really unpredictable on this car, due to sizes I’m looking at yoko a052, hear they are the best for 200 tw at the moment...re71s don’t come big enough for 16 in rims. And my pocket can’t afford Hoosiers yet...

As for seat, yes, need to get it on the floor. I’m not a fan of any aluminum seats, watched a fellow racer get trapped cause the al seat clamshelled around his body, and he couldn’t get out without help prying the seat open. thankfully no fire, but it was a scary moment for sure. Lots of people run them, and this was prob a fluke, but made the decision to stay away since then.

I got my Recaros on the floor in the old car by taking out the cross support, it gave me almost 2 more inches clearance. I don’t want to do that in my 6, so I’ll have to come up with something else, but an inch would be a huge help.

On tires, check again on the Bridgestone RE71R's....I'm on 225 on 16's & really like them, very sticky....

[infraredcalvin]

I had the RE71s on my old car (205/50/15) loved them, the new car has 245/45/16s in the rear... so trying the yokos...

[stownsen914]

Gotta pin down front of hood. PO put spacers at the rear of hood, prob to let all this air out from the nose...sheesh it’s like a parachute!

Wow. You may want to consider looking into different methods of exhausting air from the front trunk area. It's tempting to use the rear of the front trunk, but it's not ideal as it's a high pressure area (being immediately in front of the windshield). In fact, air may be flowing IN there instead of out. This might explain the hood popping up like in the pic - the air is working overtime to get out.

[stownsen914]

On the engine tune, AFRs around 10 is way rich. For sure you need to go leaner. Idle jets barely matter on track, drop the mains another couple sizes and see where that gets you.

Someone mentioned air correctors. You don't mention what size those are, but they're important too. Air correctors affect top end more than mid range. If the rich running starts like 5000 RPM and up, consider swapping air correctors (keeping in mind that the effect is opposite that of the other jets, so go larger to go leaner). If you're rich throughout the RPM range, stick to adjusting the main jets first.

Missing that much hp makes me wonder if something is fundamentally wrong. Timing is a good place to look. Make sure total advance is in the range you want, like low 30s for single plug or mid/upper 20s for twin plug. Or a major restriction on intake or exhaust. I assume you have the usual PMO style carb filters? On the exhaust, it would have to be a cork to kill 50 hp though. What do you have?

[infraredcalvin]

air may be flowing IN there instead of out. This might explain the hood popping up like in the pic - the air is working overtime to get out.

Hmmm never thought of it that way, I would like to adjust anyway, the stewards kept asking to check it as it looks like it’s not fastened down just sitting there. Also could be shock mounts preventing it closing all the way too... gotta investigate further.

The current air exhaust hole is tiny, and the cooler has no shroud, I’m losing a ton of efficiency here... sorry for the flipped picture, but here is my front trunk.

[stownsen914]

It's a little hard to figure out the orientation from the picture. A couple comments though.
On a track car, a fan shouldn't be necessary. In fact, it'll probably just get in the way of the air flow, which should be enough pretty much any time the car is moving. Fans are more for stop and go traffic situations.
As you suggest, air exhaust is just as important as the air coming in. If it can't get out, nor more air will come in, and the cooler won't do its job.
Shrouding on the inlet side is very important. Air doesn't like to go through a cooler, it'll choose pretty much any other path you give it. So the inlet shroud needs to go from the inlet and guide the air to the face of the cooler with no gaps, etc. on the seems. 1/4" is too much. You can use weatherstripping foam like you get at Home Depot for windows and ducting, or even tape to seal seams and cracks.
Shrouding on the outlet side of the cooler isn't as important. It's still a good idea, but not critical. But the air needs an opening in a low pressure area to escape the trunk. Wheel wells or trunk floor are good places. Some people just pull out those round factory plugs in the floor. Hood is good too if done right, but then you're cutting bodywork - not everyone's preference.

How are your oil temps?

[infraredcalvin]

Yeah sorry for the pic, imaging standing on the gas tank looking down - battery fuel filter are against the firewall. Oil temps are seemingly ok, car has a euro temp gauge ©, it sits at 80 then creeps to 100 where I’ll pull the fan switch, fan is on the fog light switch. My guess is that most air is going around cooler, the fan is a puller type, so that’s prob the only time it actually has decent air flowing through it.

[infraredcalvin]

I feel like the PO did his reading, bought a bunch of nice parts and put them all on the car. The whole thing seems to need initial tuning- fine tuning....

As for the car being a “track” car, technically it’s still street legal, so it’s a track oriented street car, which for now is how I’d like to keep it.

[Justinp71]

I agree may have something fundamentally wrong. Check your spark plug wires and fire order. I had an old chevy v8 along time ago that had two close wires swapped with similar issues to what you are describing. Would make sense why your afr is so low, actual unburnt fuel in the exhaust. My 3.2 with DC40 cams takes off like a banshee and yours should be faster, for comparison I am about 12.5:1 AFR at WOT on the high end.

[infraredcalvin]

@stownsen914 I never answered your question about the carb specs. Sadly I'm a noob as it relates to carbs, which is why I'm so thrown by this. When I did the carb rebuild I was able to figure out the following, but as i go down with the main jet and idle jets, my gut is telling me that everything else is too big...

Weber 46 IDA 3C

Idle jet: 50
Main jet: 140
Emulsion Tubes: F7
Air Correction: 170
Choke: 42

Air filters are K&Ns with a flat rain shield type top. Exhaust are equal length 6 headers at 1.625 and a monte 2 in 2 out muffler.

[wndsrfr]

Air filters are K&Ns with a flat rain shield type top. Exhaust are equal length 6 headers at 1.625 and a monte 2 in 2 out muffler.

I'll chime in about the air filters with rain hats....I found that mine only had slightly more than 3/4 inch from the top of the velocity stack to the metal lid. That caused what I think was significant shrouding of the air flow. My solution was to go to the ITG type filters that have only foam above the edge of the stacks so no shrouding will occur...ymmv...

[infraredcalvin]

Air filters are K&Ns with a flat rain shield type top. Exhaust are equal length 6 headers at 1.625 and a monte 2 in 2 out muffler.

I'll chime in about the air filters with rain hats....I found that mine only had slightly more than 3/4 inch from the top of the velocity stack to the metal lid. That caused what I think was significant shrouding of the air flow. My solution was to go to the ITG type filters that have only foam above the edge of the stacks so no shrouding will occur...ymmv...

Hmmm that did cross my mind, but I see this setup consistently, so I dismissed it...could be why she seems out of breath on the top end...