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View Full Version : Dyno run complete



magnusfeuer
May 20th, 2008, 10:17 AM
I spent three happy hours with Bisi Moto yesterday with Mr Bisi running the car and dyno while I did the mapping. Scott E joined us and hung out with us in the shop.

We ended up taking out a huge amount of fuel over the entire map and added 4-6 degrees of ignition over the entire rpm range at max load (max TPS).

The verdict is attached: 217HP/181lbft at the wheels. With a 17% drive train loss in gearbox and diff, we are looking at ~252HP at the crank.

The supertrapp took out approx 12 hp at the wheels. Bad, but not catastrophic. I have a map that runs 2% leaner for when I run with the supertrapp installed. One day I will find a better muffler solution.

The attached chart shows the final power run with and without the supertrapp.

The only downer to the day was we found a huge gash in the rear tire after something I've run over and that my altenator died on the way home and I had to tow the car for the last bit.

I am not sure I will manage to get a new set of rear tires (Kumho V710) and a new alternator in time for Friday, so I may have to cancel Willow Springs.


/Magnus F.


http://www.californiacaterhamclub.com/duratec_build/dyno_with_and_without_strapp.JPG

Sean
May 20th, 2008, 10:43 AM
The verdict is attached: 117HP/181lbft at the wheels.

My jaw dropped when I first read this, but then I realized it HAD to be a typo. 217/181 at the wheels is a great result! If I knew the Swedish word for congratulations, ...well, I probably couldn't pronounce it properly anyway, so I would just say: "Congratulations!"

magnusfeuer
May 20th, 2008, 11:15 AM
Typo fixed. Sorry about that.

Sean: The word you are looking for is "Gratulerar"

JohnCh
May 20th, 2008, 12:52 PM
Wow, does that thing ever take off at 4200rpm! What are you using for an exhaust manifold? 4-1? Was this done on 91 octane? If so, any detonation with the 12:1 pistons?

Thanks,
John

magnusfeuer
May 20th, 2008, 03:01 PM
I had 91 octane with no detonations. The exhaust is standard Caterham primaries and 4-1 collector with a coast fabrication canister.

The only issue (apart from the alternator) was ring flutter at 7500 RPM. A bit irritating, but I worked around it by cutting the engine at 7300. I'll talk to Cosworth about it.

/Magnus F.

Doug Liedblad
May 20th, 2008, 06:44 PM
Magnus

How can you tell you had ring flutter?

magnusfeuer
May 20th, 2008, 07:09 PM
Oil out the valve cover vent at high RPM/load combined with a power loss.

/Magnus F.

Elv15
May 20th, 2008, 09:53 PM
Magnus,

Nice result!

How does this compare to what Cosworth claims their motor to put out?

moosetestbestanden
May 20th, 2008, 10:49 PM
One day I will find a better muffler solution.

jesus christ, how many times do I have to point you here (www.raceco.com)


I am not sure I will manage to get a new set of rear tires (Kumho V710) and a new alternator in time for Friday, so I may have to cancel Willow Springs.

Can't help w/ new tyres but I have some ACB10s mounted on 13s that I'd be willing to let you use. I'll only run them 1st session Saturday but don't have too so they're yours to use if you wish. They're not exactly slicks but it's all about seat time anyay really, hint hint.

As for the alternator, well, you don't really need it. I've done entire weekends just running off of my little motorcycle battery. I put it on the charger between sessions. I always bring a charger to the track, for obvious reasons. Also, at Willow, the brake lights use more electrical energy than anything else so I just don't use em (the brakes).:D

Edit: I bring an extra battery too, always.

There's a cheeseball alternator shop in Glendale that had a replacement for mine overnight. I can dig up the name if req'd.

Edit too: Today is Tuesday. Too late to refund your entry fee and too early for excuses. So we'll see you Saturday morning.

Roll a 7
May 20th, 2008, 11:06 PM
Seems like I will have to get used to brief views of the back of your seven.

JohnCh
May 20th, 2008, 11:28 PM
jesus christ, how many times do I have to point you here (www.raceco.com)

Gotta agree with Chris on this one. An engine that nice deserves a Raceco exhaust :)

-John

slomove
May 20th, 2008, 11:42 PM
Brad, power isn't everything.....at the 2003 Infineon Sevens Fest there was a Lotus 7 S1 with skinny road tires and a wheezy engine who left most modern Sevens in the dust (apparently a long-time racer). My excuse was it being my 2nd track event ever.

Now, anybody knows how to fit a Duratec into a Birkin? ;-)

Gert

P.S.: While I don't have The Force of Cosworth origin at least I have the RACECO can. Nice piece of hardware.