1.6 X/flow Power

[philwaters]

Hi,

Just a quick question, more for my own curiosity really.

 

With all the talk of the old 1700 supersprint giving less than the 135bhp that Caterham claimed does this mean my 1600 x/flow is similarly no where near the 100bhp they quote. I am changing to a 2.0l Zetec this winter with around 160 (I trust Raceline on this) and was going to work out the increase in power/weight and it got me wondering. Anyone with rolling road experiance ?

 

 

Phil Waters

"Darling, DO you love the 7 more than me?"

"Driving OR Fixing?" wink.gif

[bstark]

I think I've mentioned this before, but my 1992 1700 Supersprint, with a fresh engine fitted circa 2000 miles ago, was roling road tested 3 or 4 weeks ago at 120bhp at the wheels. The nice man who tested it said this would equate to 135-140 bhp at the flywheel, which sounded pretty close to Caterham's claims. The engine was built by Steve Parker Racing to standard supersprint spec.

 

Bob Stark

Supersprint first-timer

[SteveP]

I had my 1700 Supersprint (also built by Steve Parker coincidentally) rolling road-ed at John Noble this Wednesday and produced max 137Bhp at the flywheel - talking to the guys there, they said that the standard Caterham Supersprint (quoted by Caterham as producing 135Bhp) generally produces around 120 - 125Bhp. Mine has a different cam and bigger Webers.

 

On the subject of rolling roads, the power map I got showed peak power at the wheels of just 82.5 Bhp but then factored in 50 odd Bhp of drag which gave the flywheel figure.

 

Is this likely to be a feature of how this particular rolling road works and therefore on the road is actually producing say 120Bhp at the wheels or am I really losing 50 Bhp through transmission, etc

 

Steve P

[Graham Sewell]

To lose 50bhp from 135 seems very high. Most rolling roads use 20% to 25% loss in transmission. That would indicate that the 80bhp at the wheels equates to 100bhp at the flywheel.

 

This becomes a little less relavent if they did a run-down test to measure the resistance through the transmission. If you really are getting 50bhp losses, try some snake oil (Slick50) or just top up the gearbox and diff!

[ashaughnessy]

To expand on my post to the other thread in the Wanted section, I looked at my rolling road printout last night. It said 102bhp at the wheels and they worked out this meant 131bhp at the flywheel. They did this using what Graham called a run-down test, measuring the transmission losses when they closed the throttle and let the car run back down to idle. My engine is standard spec supersprint (I think - I didn't build it) and this test was done in about 1991 when it would have done about 20 or 25,000 miles (I think - I bought the car second hand from caterham and there was some question about the mileage).

Anthony

[Roger King]

To answer Phil's question. A healthy 1600 X/F with a pair of 40DCOE carbs will indeed produce around 100bhp.

[philwaters]

Thanks guys, ooops didn't mean to start a war of power amongst you 1700 boys teeth.gif

Honest

 

 

Phil Waters

"Darling, DO you love the 7 more than me?"

"Driving OR Fixing?" wink.gif