SCCA G-Production 914, Anyone runnig one? Options

[don9146]

We have people on the board that road-race their 914s in F-Production and E-Production, but does anyone race their car in G-Production (on the board or know of someone that does)? A quick glance through the rulebook makes me curious about a few things with the 914 in that class:

1. How fast are the G-Production cars compared to ITA, ITS, and F-Productions cars?

2. How can you modify the 914 engine for this class and still use the "original type fuel-injection only" (from page 272 of the 2006 GCR)? Obviously, 10.5 to 1 compression pistons and a 0.420" lift cam would cause the stock F.I. system to go nuts. So what "original type" can be substituted?

3. What type of reliability can you get from a 10.5 to 1 compression type 4?

4. Is the 914 competitive in G-Production?

5. Is the popularity of the Production Category cars waning across the U.S., or are there just few of them around where go to amateur races (Road Atlanta, Barber Motorsports Park, St. Louis)?

6. Would racing a 914 in G-Production be any cheaper than running a 914 in F-Production?

I am looking at a 944S that has been built for the ITS Category this week. I would like to road race a 914, but ITB would be too slow for the money and time, and an F-Production car seems too expensive and time consuming. Would a G-Production car be a good fit?

Thanks,
Don

[bam914]

I have looked at doing a GP 914 but have decided not to. Most GP cars in the southeast turn times a little slower then ITA cars. The suspension would be cheaper then FP and EP, since you can not relocate pickup points. Most of your money will have to be spent on the engine. You are not allowed to do any porting, just match porting 1". So to get the flow up will be difficult. You will also need some form of programmable ECU. All that is needed of the FI system is the stock intake runners, plenum and throttle body. At 2000# it would need to make over 150 to be competitive. I am currently in the process of building an ITC 914. Which should prove to be just as challenging. You never know I might converted to GP or GTL if I get it classified in a few years.

It deffiently would be great to see more 914 at the track.

Blake Meredith
ITC 914

[brant]

also...

I know that 10.5 to 1 can be done...
but I think you'd find that compression to leave you with a VERY stressed and short lived motor.
most mild race motors are around 9 to 1

something above 10 to 1 is going to need monthly freshening I'd guess.
brant

[Brett W]

Contrary to popular opinion compression does not wear a motor out and faster. If it did then diesel engines would need a rebuild on an hourly basis and a Top Fuel car would last forever (6.5:1).

RPMs= ruined peoples motors. This is what kills engines. A 914 motor making 110hp with that kind of compression and a good cooling system should easily last years of racing. Have to turn a sensible rpm though.

[don9146]

RPMs= ruined peoples motors. This is what kills engines. A 914 motor making 110hp with that kind of compression and a good cooling system should easily last years of racing. Have to turn a sensible rpm though.


At 2000# it would need to make over 150 to be competitive.

What type of hp, usable power-band, and maximum RPM would I get from a well-built G Production motor? It is limited to 10.5 to 1 compression and a 0.420" lift cam (not sure where a 0.420" lift cam would make power). Is 150 hp even possible? Would it be reliable with that kind of hp?

The suspension would be cheaper then FP and EP, since you can not relocate pickup points.

Didn't see that at a casual glance through the GCR. Is that what "Restricted Suspension" means when the 914 specific rules are borken out on page 273?

Most of the answers I am reading are confirming what I feared; as much as I would like to road race a 914, there are other cars I should run if I want to go quick on a limited budget (like an ITS 944S).

Still, does anyone run a G Production 914? Or know anybody running one?

Later,
Don

[bam914]

I would think you could get close to 150. Jake would be the one to ask. The suspension is like IT, T-bars in the front. You can replace the control arms with alt. ones. I would think the engine would be fine for a few season.

Blake
ITC 914

[ChrisFoley]

We have a GProd racer here on the board. Randy (aka Kart54) just ran his first (double) race weekend with his new car a couple of weeks ago, taking home a second and a first place trophy.

150hp will be a challenge, since I don't think any legal cam currently exists that will maximize the engine's potential under the rules restrictions. The engine should last a season or two without problems though.

[groot]

If you have people to race with the ultimate speed is not an issue in my opinion. I ran in ITC and ITB for years and had many great races.... even though I never lapped the track as fast as an ITA car.

Randy runs a GP 914 (as Chris mentioned) and there's another dude in OH that's converting one now. IMHO it's untested waters, might work, might not. Getting 150 out of a FI motor will cost you serious cash (very serious cash) and probably never make 150 with the limited prep rules.

A word about relocating suspension points and costs. If you source your parts correctly it can actually be cheaper if you build it yourself, because you're not forced into paying Porsche prices. I, personally, don't think that's where the time is on a production racer. The time is in the motor.

[Thorshammer]

So lets look at this as best we can.

G prod Interesting:
I doubt this combination will make competitive HP. @2000lbs making 150 or so HP which is what it will take.

My ideas:
Engine:

Intake system:

So you can have a 1.8 liter, so the intake must remain stock, So start with an L Jet intake, and you will want to use a stand alone fuel managment system, that way you can remove the air flow meter. It will be very important to have a cool air box above the throttle body that is sufficient in air volume, and the addition of a very large velocity stack will be needed on top of the TB. Remember that you will be fighting the length of the intake tract, so the cam grinder and exhaust maker will have to be very sharp.

Cylinders will be Nickies, of course, the 94mm pistons will need to be the very lightest things you can get your hands on. 20mm pins I would suggest , because the intake will be the RPM limiting factor, JUST THINK RESTRICTOR PLATE RACING. I would also use a very very low tension ring pack, like an XC or the like. I personally would run a two ring piston with a vacuum pump, but then again I am a whack.

Con rods will prove to be a big problem, I have a real problem with this one, THERE IS NO COST REDUCTION IN RETIANING STANDARD CON RODS. But the time you prep them, you have just as much in rods as you would to buy some carillos, and they will last longer than the car. The stock rods we used to throw away after 40 hours, then shot peen,rod bolt and polish the beams after magnafluxing them, what a pain in the ass.

Good on you with the crank, I would turn it .040 Ion nitride it after REM process the entire crank, then a couple small oiling mods.

Straight cut cams gears, REM finished

Cases, After getting a real good set, I would port and polish the entire case paying special attention to airflow underneath the pistons and how oil is going to drain off of everything, then maybe a crankshaft scraper of some sort, maybe Jake has an idea or something on this already.

Oiling system. most of what I would do will push the rules envelope, but I would instal a 3 quart accusump, a oil trap at the bottom of the crankcase and a belt driven vacuum pump to draw the crankcase down.

5.5 Tilton Clutch with one tiny little itty bitty flywheel.

Jake can build this, but not sure of his available time, Len Hoffman can do the heads and manifolds. With the lack of compression and camlift, this engien will have to burn the available mixture very well.

Keep the oil as low in the crankcases as possible, while still getting good oil flow?? gonna be tough.

The stand alone injection will be a density system like: Motec, DTA, Electromotive (not recommended). This will give precise control of timing and fueling events, and you will need this.

Coatings: Anything that moves gets something, True thermal barrier on the exhaust ports, DLC on the valve stems, Thermal dispersant on the heads.

DTM cooling shroud, ribbed belt drive for fan and vacuum pump, Remember you may use any crankcase evac system but it must not connect to the exhaust system.

Ceramic lifters, REM the cam, which must be very special, this will take a real grinder and alot of R&D

"Thats all I got to say about that"

Chassis:

Think as small adn as sleek as you can. How will it go through the air, If you want to build a closed car, don't do this project, if you want a high hoop cage, don't do this project.

Front should'nt need any flares at that track, rear should only need a very small flare, which I would suggest stretching the stock fenders.

You will need air from the front to the engine fan, by means of a front to rear duct, I would pick up the air via the small holes at the front header panel of the front trunk. You can't cut this out, but you can build an air dam that funnels all the air in the center of the car through these holes, on the trunk side build a small plenum, and have two three inch tubes throught he car and should provide excellent cooling for the engine, and some free HP (due to not having to drive th cooling fan as hard)

The front hood needs to fit perfectlyto the front fenders, as should the front bumper and front airdam. This is a must

Use Aircooled racings fiberglass windscreen, the standard Ginther screen is too low. and will not guide the air over the cockpit very well.

Fill the rear fiberglass bumper with house insulation foam, so it does'nt act as a parachute, it will also add a little protection in case of a rear end hit,

The air box should fit perfectly to the bottom of the engine grill and seal, so that all of the air that is cool goes in, not the hot air around the engine. Remeber it is getting fed by the front ducting.

Install the air deflectors at the bottom of the pan, it does make a big difference.

Headers, I would consider building a set of headers that will take the exhaust tubes foward, not rearward, I think there is something to gain there, and have the Final tube to exit in front of the wheel, out of the rocker panel. i would make it so that the collector could be changed and it could go out either way.

make sure the roll cage is built right in front of the targa bar, and that the vertical roll cage element allows you to tuck your head close to under the main roll hoop.
The front low hoop should be back from the inner dashpanel, so that the line from the main hoop to the front hoop will pas over your helmet, I would start by buying the seat,pedals and the windscreen and then going from there.

The chassis needs to be of adequate stiffness, Brett W and Kevin Groot have studied this I think.

Front mounted 8 gallon fuel cellshould be plenty,and use an in tank pump, I have run FI racecars on a single optima battery without an alternator, but it's up to you, gotta charge all the time.

Suspension:

Torsion bars, 22, 225 lbs rears, 1 1/8 front bar.110 wall, Konis 8610, call Roger Kraus, HPH etc, watch the ride height, as too low will screw up the front RC.
Again see Kevin or Brett.
Aways look to make the suspension as friction fre as possible, such as the rear inner pickup point relys on the flexibility of the inner point to adjust the alignment, I woudl suggest roller bearings and a spherical bearing in the inner point to keep it out of a bind. the outer is not a problem.

Limited slip in the trans.

All I can think of sorry to be so long winded.

Erik Madsen

Post Script: I would love to see someone with a max effort for one of these cars.

[HotRod]

So lets look at this as best we can.

G prod Interesting:
I doubt this combination will make competitive HP. @2000lbs making 150 or so HP which is what it will take.

My ideas:
Engine:

Intake system:

So you can have a 1.8 liter, so the intake must remain stock, So start with an L Jet intake, and you will want to use a stand alone fuel managment system, that way you can remove the air flow meter. It will be very important to have a cool air box above the throttle body that is sufficient in air volume, and the addition of a very large velocity stack will be needed on top of the TB. Remember that you will be fighting the length of the intake tract, so the cam grinder and exhaust maker will have to be very sharp.

Cylinders will be Nickies, of course, the 94mm pistons will need to be the very lightest things you can get your hands on. 20mm pins I would suggest , because the intake will be the RPM limiting factor, JUST THINK RESTRICTOR PLATE RACING. I would also use a very very low tension ring pack, like an XC or the like. I personally would run a two ring piston with a vacuum pump, but then again I am a whack.

Con rods will prove to be a big problem, I have a real problem with this one, THERE IS NO COST REDUCTION IN RETIANING STANDARD CON RODS. But the time you prep them, you have just as much in rods as you would to buy some carillos, and they will last longer than the car. The stock rods we used to throw away after 40 hours, then shot peen,rod bolt and polish the beams after magnafluxing them, what a pain in the ass.

Good on you with the crank, I would turn it .040 Ion nitride it after REM process the entire crank, then a couple small oiling mods.

Straight cut cams gears, REM finished

Cases, After getting a real good set, I would port and polish the entire case paying special attention to airflow underneath the pistons and how oil is going to drain off of everything, then maybe a crankshaft scraper of some sort, maybe Jake has an idea or something on this already.

Oiling system. most of what I would do will push the rules envelope, but I would instal a 3 quart accusump, a oil trap at the bottom of the crankcase and a belt driven vacuum pump to draw the crankcase down.

5.5 Tilton Clutch with one tiny little itty bitty flywheel.

Jake can build this, but not sure of his available time, Len Hoffman can do the heads and manifolds. With the lack of compression and camlift, this engien will have to burn the available mixture very well.

Keep the oil as low in the crankcases as possible, while still getting good oil flow?? gonna be tough.

The stand alone injection will be a density system like: Motec, DTA, Electromotive (not recommended). This will give precise control of timing and fueling events, and you will need this.

Coatings: Anything that moves gets something, True thermal barrier on the exhaust ports, DLC on the valve stems, Thermal dispersant on the heads.

DTM cooling shroud, ribbed belt drive for fan and vacuum pump, Remember you may use any crankcase evac system but it must not connect to the exhaust system.

Ceramic lifters, REM the cam, which must be very special, this will take a real grinder and alot of R&D

"Thats all I got to say about that"

Chassis:

Think as small adn as sleek as you can. How will it go through the air, If you want to build a closed car, don't do this project, if you want a high hoop cage, don't do this project.

Front should'nt need any flares at that track, rear should only need a very small flare, which I would suggest stretching the stock fenders.

You will need air from the front to the engine fan, by means of a front to rear duct, I would pick up the air via the small holes at the front header panel of the front trunk. You can't cut this out, but you can build an air dam that funnels all the air in the center of the car through these holes, on the trunk side build a small plenum, and have two three inch tubes throught he car and should provide excellent cooling for the engine, and some free HP (due to not having to drive th cooling fan as hard)

The front hood needs to fit perfectlyto the front fenders, as should the front bumper and front airdam. This is a must

Use Aircooled racings fiberglass windscreen, the standard Ginther screen is too low. and will not guide the air over the cockpit very well.

Fill the rear fiberglass bumper with house insulation foam, so it does'nt act as a parachute, it will also add a little protection in case of a rear end hit,

The air box should fit perfectly to the bottom of the engine grill and seal, so that all of the air that is cool goes in, not the hot air around the engine. Remeber it is getting fed by the front ducting.

Install the air deflectors at the bottom of the pan, it does make a big difference.

Headers, I would consider building a set of headers that will take the exhaust tubes foward, not rearward, I think there is something to gain there, and have the Final tube to exit in front of the wheel, out of the rocker panel. i would make it so that the collector could be changed and it could go out either way.

make sure the roll cage is built right in front of the targa bar, and that the vertical roll cage element allows you to tuck your head close to under the main roll hoop.
The front low hoop should be back from the inner dashpanel, so that the line from the main hoop to the front hoop will pas over your helmet, I would start by buying the seat,pedals and the windscreen and then going from there.

The chassis needs to be of adequate stiffness, Brett W and Kevin Groot have studied this I think.

Front mounted 8 gallon fuel cellshould be plenty,and use an in tank pump, I have run FI racecars on a single optima battery without an alternator, but it's up to you, gotta charge all the time.

Suspension:

Torsion bars, 22, 225 lbs rears, 1 1/8 front bar.110 wall, Konis 8610, call Roger Kraus, HPH etc, watch the ride height, as too low will screw up the front RC.
Again see Kevin or Brett.
Aways look to make the suspension as friction fre as possible, such as the rear inner pickup point relys on the flexibility of the inner point to adjust the alignment, I woudl suggest roller bearings and a spherical bearing in the inner point to keep it out of a bind. the outer is not a problem.

Limited slip in the trans.

All I can think of sorry to be so long winded.

Erik Madsen

Post Script: I would love to see someone with a max effort for one of these cars.

[kart54]

Time to chime in I guess,

I've gotten great suggestions from Erik Madsen, Chris Foley, John Rodgers and a host of others. Erik's ideas are always the ideal dream car but for me not practical.
I'm the guy running the G prod 914. "Car 54 Here I Am" Cal Club, So cal region of the SCCA.
The car runs stock 1.8 fuel injection which is widely tunable despite what you have read here. It takes a talent however. In my case, it's Gary Betz, a former Porsche factory race mechanic from the 60's and early 70's. The stock set up can be made to flow more fuel for a longer duration just takes a little trial and error. I was really disappointed when I initially read some of the comments on this board and then I found out they just weren't correct. All connections on the stock hose are plugged, stock air box thrwon away, custom air cleaner mouth with a cone shaped Kand N pointed at the engine cover. Engine cover completely cut out like the 914-6. Compression is estimated at 10:1. I say estimated because the engine has been together for three years and still runs well enough and develops enough balanced compression that there is no reason to tear it apart. After this season I'll probably put new rings and bearings in it.

Ran my first race weekend about a month ago. Plenty of cars to run with, many not in my class. On Sunday I was running in the middle of a pack with HS and some of the F prod cars time wise. I was even pushing a Super Prod camaro driver who was learning his car. Lots of wheel spin with that big motor.
I'm still learning my set up and had planned for this to be a learning year but as it presently stands, I ran second on Saturday and first on Sunday and am leading the Cal Club points so we'll see how the season turns out.
I don't have the money or the sponsorship to run Nationals so that is out of the question. Didn't plan to this year anyway, We'll see what next year brings.
As far as lap times, I'm a 2000 pound car with probably no more than 120-125 horsepower if that but the last lap I ran on Sunday was 2 seconds off the G prod lap record for that track in that configuration. I improved every lap and 8 seconds overall. I am running with the roof on and using it to change the aero of the car. It's lifted in the rear and ported (that can be explained and was a suggestion on this site.)
Top speed at Willow was 148 in 5th at 6400 rpm. Plenty for me in that car. It twitches like crazy in turn 9 at that speed (Yes, I said turn).
I've driven karts, BMW's, Stock cars and an open wheel car or two and this is the most fun I've had but it's still pricey. Expect at least a $1,000.00 per weekend and that's if you don't have any problems. I figured the F prod car at $1500.00 so there is a little savings there.
One major change from what Erik said; the car is almost all fiberglass at this point. Doors are steel and part of the front fenders. I'm also not running as trick an oiling set up as he mentions. Mine is Tuna can and two oil coolers with fans. Oil coolers mounted in the rear alla OTTO at Otto's of Venice, a man with more time racing 914's than all of us combined on this list. At this point the car is staying cool enough but I need more alternator output which I'm working on.
Suspension;
As mentioned elsewhere on this list the stock 914 suspension is more than adequate. Mine has coil overs with adjustable Koni yellows in the rear and adjustable Koni's in the front with a Weltmeister adjustable sway bar. No limited slip. This is one where I respectfully disagree with several people here, I have a spare transmision with a limited and another with a full locker but running 10 inch wide sticky race slicks it's almost impossible to spin them in 3rd thorugh 5th gear which is where your going to be spending most of your time on the track. The car also rotates better through the tight corners without the limited slip. If you want to be able to do cool first gear burnouts, go for it, otherwise, spend your money on other areas. I do have 5 lug front and back. The fronts are Eric Shea's cryo treated rotors and they show no wear to date, the back are 914-6 5 lugs. I also have cockpit adjustable brake bias which helps alot. Stock calipers as required by the class, no fade so far. Porterfield 4S pads, the best in the business.
My Comment on G prod? Go for it and I'll see you at the track.
I've posted a pic of my car with this but my new graphics are done so I need to post a new one with the Car 54 grapics. That's for another time
Feel free to pm me and I'll finish the list on whats been done to the car.
2 guys from Ventura saw me run at Buttonwilow and are so excited they are building G prod Porsches for next year so there will be at least three on the left coast by this time next year.
I'm a one man crew with no help of any type so it's a little bit of a challenge but I've always liked a challenge and there are a lot of friendly people in SCCA always willing to talk to you.
GOOD LUCK and Go For It. Don't wait for the perfect car, it'll never happen.
Randy
"Car 54 Here I Am" G prod Porsche from Ventura, CA

[groot]

Top speed at Willow was 148 in 5th at 6400 rpm.

Randy,

This sounds unlikely with 120-125 horsepower. What tires and what 5th gear are you running?

Not trying to bust your balls or anything, but a certain National Prelude in EP runs 145 at Road America (really, really long straight).... and he's got some real power.

[Jake Raby]

Erik's post was near spot on!

150 HP from the G prod engine would be a challenge, no doubt- even for me... It could be done, but with all the limitations trial and error and a lot of dyno time would be a necessity.

I could help you out with parts to get it done, but my race engine program is full up right now- I can barely support the 5 teams I have on board presently.

[Thorshammer]

Kart 54,

I am glad you finished your car and are racing in G prod. 148 is highly unlikely. Watkins Glen is the longest track I race at and last year, being just .02 off the track record, I was HP maxed out at 141 MPH. Maybe your calcs are a tad off. As for my information on the G prod car, anyone can build this car and spend much less than what my G prod build would cost. Here's the way I look at it.

SCCA will never take you seriously until they see you build a "max effort' car. I am glad that you have come within 2 seconds of the G track record. 2 seconds off the track record in my Division will place you 5-7 in class, and have F cars passing ( I run in E prod) you, so 2 seconds is a fairly large amount. The nearer the track record you get, the harder the next incremental decrease in lap time is.

For the initial poster, you will have a great time, but ask yourself one basic question, What do you plan to accomplish. Is it regional racing and a fun car, if the answer is yes, then you can build this car with stock injection, and quite a fe w less trick parts than I suggested. If your answer is National racing and you are like me and can't stand losing or not competing near the front, then really think about building a G prod car, because I think you will find this will not be a easy road, and it will take concession's from the CRB to make it competitive.

Ask Kart 54 how difficult it was to get the track spec changed so he could run the 15x7 wheels. I not only wrote a letter, but provided info so he could get this done, but it wasn't easy. Asking for performance changes is even harder.

In some respects I sometimes think SCCA stands for Still Can't Comprehend Anything. You have to be patient with them, and have all of your little duckies in a row.

Erik Madsen