It's been a while coming, my rebuilt engine. But apparently, "they only let you drive it when it's ready". SE engines... "never rushed" ;) Short story (even shorter): Pete's made a point of doing the first mapping session on 95 RON (for the yanks, that's "the sh*t stuff" over here). If you've seen the rolling road in Witham (last SE RR day) you'll know there's virtually no airflow directed at the intercoolers and I don't have any kind of IC fogger or trick stuff like that. So charge-air temp is already a problem, using shyte fuel, and kinda demanding boost to be kept low to stop det. Todays result, which I'll be calling my "economy mode" or "safety setting" or something equally low-key, on Engine Advantages dyno (that has a reputation for reading low, but OK for a SE RR comparison), running at 1.0 bar:

 

432.5 bhp @ 7534 rpm (flywheel)

438.5 lbft @ 4090 rpm

 

It was still making decent power at 8244 rpm - bit hard to tell, but looks like it dropped to around 410 bhp.

 

I'm relatively chuffed. I wasn't really expecting stupendous power at the first session, running on a tank of used cooking fat. I certainly wasn't expecting it to be revving that high! Next week(!) it'll be going back with a tank (/several tanks) of Optimax for session-2 and we'll see how much boost it'll cope with then. Keeping in mind I'm still only running a single MAF, that may get chucked in the bin for a dual-POP.

 

I've gotta also say, Pete's sorted out the wobbly idle and it's absolutely smooth-as-silk to drive. The power comes right in when you need it and just keeps going and going. I'm trying to make a point of letting off slightly as the boost starts coming up because it simply lights up the back wheels if I blatantly bang the throttle to the floor (straight-line, dry, whatever). It's a lot of fun, but I got into a horrible tank-slapper earlier that I didn't think I'd recover from, just trying to get a little drift on from a standing start. The power came up a darn sight faster than I was expecting. Oops.

 

So, yeah... to be continued :)

 

Questions / comments?

Only just seen this post... very interesting!

 

Like you I'm amazed how flat it all looks... but all that extra power at the top end has buggered your gearing... if you stay down til power starts to drop off, the upshift will drop you into the new gear -past- peak torque!

 

In other words, you've got so much power there you dunno what to do with it. :rofl:

 

Not that it matters on a sprint, but you're missing out on a top speed of 200 mph ;)

 

I guess different cams accounts for most of that? But it looks to me like you've got room for more lag, so I guess that means you can up the boost!

Well I have the option of shifting the cam timing to give a bit more torque at the expense of peak bhp, but talking to Pete about it today, I think he'd like to get my spec build to higher peak bhp to start. The spec's kinda sold on making an amount of bhp, so if it doesn't, it's just gonna confuse potential customers I s'pose.

 

There's something very wrong with that plot. It's not strictly true :) The dip in the rwbhp is a bit of a clue. I didn't know til today. Peak bhp is really higher in the rev-range than it looks.

 

Still waiting on dyno day-2.