Thread: Comments on this dyno sheet please

Yup Ben, 12.8:1 but it seems very difficult to adjust in places, in terms of actually getting the AFR to change.
I think my fuel map adds loads at low rpm, zero at midrange, and takes out loads at the top end.
As you say, given loads of driving time i could get it tweaked but i haven't done much mileage in it unfortunately.

I had the UK Highport @ 10:1 down as 150hp at the fly based on the '91/'92 Primera P10 eGT with no Catalytic convertor, and i think i must have mis-read 13-15% all those years ago as 13-15hp! Definitely my mistake so apologies there, and thanks for the info. For some reason i always had the UK Highport at 150hp fly and 132whp (12% loss), which i guess is why my 154whp bugged me a little.

Mike - thanks for the input. I seem to remember you posting something about crystals and distributors in the last few days, as a way of raising the rev limit?
Thanks also for the info on the Gen VI, wonder if it's runner 4 as that plug looked i thought a touch lean when i changed them a few weeks ago...
Never messed with the cam gears, but knew i'd probably need them, so that looks like a job to do when i rebuild this thing whenever that time comes.

Yup Ben, i think you're spot on with the intended Gen VI useage. I didn't realise how weak those Piper cams were until it was too late. About equivalent with the JWT S3's i think? So i could do alot better with far more lift i'd imagine.

Thanks

well a higher compression ratio and increase the overlap will help all through the powerband.
Some people suggest about 13.2:1 for peak power in an SR20 engine. a tailpipe sniffer will usually read leaner as reversion pulses pull outside air a little way back up the tailpipe.
Also make sure you have the wideband just before the cat, as heat kills them easier than a narrowband.
The crystal change will raise the rev limit about 10-20%, but then you have to retune the whole midrange, would have been easier with a calum realtime, rather than being dependant upon dastek for each retune.

Mike

Subscribed - I have a UK 10.1 motor and I'm curious on the nubmers as well. You have a P&P job on the head you say? Seems like the WHP would be around 165WHP.

Not to worry there, it's just an old Superchip i've wired on to the ECU, wouldn't tie myself to Dastek when as you say, i could have all the fun myself
Got the wideband at 9 'o' clock and just before the cat, and it's now taken to giving an E8 on the display after about half an hour of driving. Must check that out.
Leaning out a touch wouldn't be a bad idea, but the last 2 MOT's have been a nightmare and after a while of sitting in and playing with the Apexi, i found i've had to richen both times...don't know what gives there.
I don't mean to put you on the spot but would knocking the intake cam back a degree, and the exhaust two degrees be worth a try (reducing both by 1deg, then the exhaust 1 further again to increase the overlap)?
Higher CR will be the next project , but where i'm going, the bottom ends are back to 9.5:1 stock, and any form of fuel or ECU modification is illegal so i'm taking the stock bottom end from a highport with me and the complete head and rest of the bits from this project engine, then weigh up my options once i've got settled. I might have to become the kind of concealment yet

Thanks Mike

Hey, I posted in your thread a few weeks ago to say i'd be dyno-ing.
Interested to see how yours comes out, i'd expect you to do a hell of a lot better than me to be honest. Check out the weak 11.1mm lift in my first post with the spec.

that seems about right to me comparing it to others. maybe a tad bit low, but im not familiar with those cams your running. what is your timing at ?

all though i must mention i dynoed at 154whp with my old n/a 10:1 with s4's although the motor was on 8 !!! degree's timing.

stratton.

Well her in the uk emissions are measured at idle, 2k ish and 3kish, so leaning up top and leaving it richer down low should help both aims. I would have thought that 1 and 2 degrees of retard for the cams would be a good start.

Everything else in the build is set up for quite a lot of power, it seems the cams are holding you back? but power is still rising at 7k5, the peak could be anywhere above that!

Mike

Damn, 8deg?!
Timing is currently at stock 15deg as i've wired in an ancient 'Superchip'. What i'd really like to know is what the hell the timing map in it is like! Think i'll have to get a calumn ecu when i start this project again after i've moved.

Cams are maybe like the JWT S3's, spec as follows:

Duration: In = 268 Ex = 268
Valve Lift: In = 11.1mm Ex = 11.1mm
Timing: 24-64 64-24
Full Lift: 110deg 110deg

Yup, i was having bother at the 2-3K section i think, was on the gas analyser for so long holding it at that rpm while i messed about, that the damn coolant expansion tank boiled over!

Will do that with the cams when i rebuild it, out of time before i move now, got to start tearing the NX down and return to stock asap

I always knew i should have gone for at least S4's if not the low C series!

Yah, I read you had a 10:1 compression UK motor, but it slipped my mind as I read the rest of the specs.

Whoops... =/

Yah, you're at 150 flywheel HP stock and I believe about 128 WHP, which means you've gained 26 WHP with your mods, which seems quite a bit low. =(