"Racing gas" in a Boxster? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

FUHRIUS · 03-16-2009, 07:34 PM

I stopped to fill up at the BP station in downtown Saratoga before heading up hwy 9 to Skyline over the weekend and noticed a pump of 'racing gas'...don't remember what octane rating it was (I suspect it is high 90's). I know some folks run flashed ECU programs that are tuned specifically for 100+ octane...but anyone run high octane fuel like this on occasion? btw, it was like $8 / gallon.

heyjae · 03-16-2009, 07:44 PM

As long as it's not leaded racing gas, you can run it. It's basically a waste of money though. I've tried it on occasion at the track and couldn't tell any difference. I have the GIAC program, BTW. It's a different story for forced induction cars with higher boost pressures.

FUHRIUS · 03-16-2009, 07:49 PM

I'm looking into doing some additional mods for running at the track more often...see you're running the hardtop and a wicked-big rear wing...what else?

heyjae · 03-16-2009, 09:00 PM

What you have is more than enough to get on the track

Frankly, I like to keep it reliable to maximize track time versus repair time, so I kept motor mods to bolt ons, but made a lot of other mods with the goal of reducing weight. Motor: CAI, headers, cat delete, exhaust, GAIC program and underdrive crank pulley. As for suspension: JIC coilovers, GT3 front sway, H&R rear sway, drop links, stock brakes with Pagid black pads, ATE fluid, SS lines (not worth it, btw), GT3 brake ducts, BBS LM w/ Nitto NT01 and spacers as needed. Other stuff: carbon fiber hood, CF hard top and CF GT3-style front bumper (and just for style CF side mirrors and side air ducts). Cut out the rear bumper on either side of license plate to let out the hot air. Removed the carpet, center console, convertible mechanism, spoiler mechanism, rear bumper reinforcement, and front trunk carpet and trim. Installed 11 lb battery, kevlar Cobra seats, 6 point harnesses, 6 point bolt in cage, B&M short shift. And I just raised the wing 2.5 inches to get cleaner air.

Anyway, based on what you already have, I'd just upgrade brake pads, fluid and maybe add the GT3 brake ducts (they're only $30 from suncoast http://e-partssales.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=P&Product_Code=airducts&Category_Code=986boxsters and take 20 minutes to install). With that setup, I've never had problems with the stock brakes with the right pads and fresh fluid. And that includes running Buttonwillow #18 CW, which includes braking hard from 138 mph for a 2nd gear turn.

cas951 · 03-17-2009, 06:33 AM

Since you're in Ca and using the old 91 Octane yes it would make a slight difference. Porsche programmed our cars to compensate for lower octane fuel. It won't be a significant change but I would use a mixture or race/91 octane to have a 93-94 octane mixture.

On turbo cars yes it makes a big difference.

heyjae · 03-17-2009, 06:45 AM

True. There's probably a slight difference. Just not enough to make a real world difference worth $8 a gallon on a non-turbo car. Once I get my Mini back on the road again, I'll have to see if it makes a difference with that. It is supercharged and I have a pulley overdriving the supercharger.

edevlin · 03-17-2009, 08:55 AM

I ran a dyno with normal high test and racing fuel in my 2.7L Boxster and picked up a few HP with the racing fuel. Just an experiment, I think it cost me 130.00+ for the tank of racing fuel, I dont think I will be doing that again anytime soon....

Ed

:dance:

cas951 · 03-17-2009, 09:27 AM

I wouldn't use a tankful of 100 Octane on any car unless you have special fuel/timing mapping for it. This would be a waste of money. I don't think our cars fuel mapping can adjust to that level of Octane. Maybe 94-95 octane it would be able to adjust and provide minimal result and better response from the engine.

Lil bastard · 03-17-2009, 09:35 AM

I ran a tank of 100 octane race gas when a local station had it on sale for $3.879 in order to sell it off and drain their tank so they could and use it in the coming winter for Kerosene (they do this every year).

The car ran great, smoother, most likely due to the fuel being dryer (race gas doesn't absorb as much water). It was likely making a couple more ponies, but not like the Second Coming or anything.

IMHO, if it's not competitively priced with street gas, it's waste of money.

FUHRIUS · 03-17-2009, 10:10 AM

guys,

thanks for the help.
can you give me some advice on what brand / model to get when I look for:

- pads - sounds like pagid is the way to go - what style
- brake fluid
- seats - safe and reasonably priced
- harness
- is that hardtop structural? or is it better to get a roll-bar extension such as the brey-krause?
- you guys using HANS?

thanks

my car's basically been a street queen - most mods from prior owner. I've done a number of auto-x / track days / high performance racing schools over the years but never had the boxster on the track...somewhat ironic.

glam shot included for your (possible) enjoyment.

edevlin · 03-17-2009, 01:46 PM

"I wouldn't use a tankful of 100 Octane on any car unless you have special fuel/timing mapping for it."

I dont know, I probably would have tried it if I had a stock ECU just to try it out, such is my nature. In my case I got in touch with the folks that did the remapping of my ECU and asked them if the program would respond to higher ocatane fuel.

They said it should, and when I put in the racing fuel, the car did seem to run a little differently, seemed a little quicker with the butt dyno, and gurggled more when letting off the gas. When I ran it on the dyno, it looks like it picked up about 5hp with the racing fuel, so in my case it seemed like it was doing something.

Ed

heyjae · 03-19-2009, 04:45 PM

Quote:

Originally Posted by FUHRIUS

- pads - sounds like pagid is the way to go - what style
- brake fluid
- seats - safe and reasonably priced
- harness
- is that hardtop structural? or is it better to get a roll-bar extension such as the brey-krause?
- you guys using HANS?

Nice car. Are you sure you want to ruin it by taking it to the track

There are a lot of valid options for equipment. This is just what I use:

Pads - I use Pagid Black (the race version, RS14), but they are true track pads meaning they squeal loudly and need to be warmed up. Orange make less noise and need less warm up and are still very good. Lots of other options and opinions.

Brake fluid - I use ATE type 200/super blue. Another good choice is Motul. Motul is higher temp, but should be flushed more frequently.

Seats - I have Cobra Suzuka S, but I've seen lots of people with Sparco Evos. It's worth it to go to a retailer and to sit in them to see what fits you best. The Boxster is tight, so fitment might be an issue. Get one with a FIA label, not a cheap knock off.

Harnesses - I have one Sparco and one Schroth. Again, lots of good choices. Just be sure to get a 6 pt harness as there is no reason not to. Installing is actually easier since they use the lap belt bolts. Be sure they are dated.

Hardtop - I think I read the stock hardtop adds some structural rigidity, but I wouldn't count on it to protect you in a roll over. Get a BK rollbar extension. Used it's $300 or so. I had one before I installed my cage.

HANS - I don't have one, yet. Honestly, not many DE folks do. I plan on it though.

cas951 · 03-20-2009, 06:23 AM

[QUOTE=edevlinThey said it should, and when I put in the racing fuel, the car did seem to run a little differently, seemed a little quicker with the butt dyno, and gurggled more when letting off the gas. When I ran it on the dyno, it looks like it picked up about 5hp with the racing fuel, so in my case it seemed like it was doing something.

Ed

[/QUOTE]
Yes the car will run better and will have a slight gain in HP. But you don't need a full tank of 100 Octane to get this. All you need is a mixture of 100 Octane and 91 to equal 94-95 Octane. Your fuel mapping will max out at 95 Octane.