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?

sounds good, can wee see the graph? :)

Depends how good your eyesight is. I'm holding it out the window now... OK? Sorry ;) No scanner here. Monday alright? Or I can do a free-hand approximation!?

8244rpm :eek:

 

Thats some pretty respectable power there.

 

How about a couple of CO2 fire extinguishers to cool things down next time?

8244 rpm! - tell me about it! I almost shat me pants when I saw that! :D

 

The power's OK for an initial setup. I'm sure crazy-eddie's thinking the same thing - you get a first figure and expect to keep building on it. He's got more mapping lined up so I'm sure (after being the phattest at the last SE RR) we'll see bigger numbers from his too.

 

CO2 stinguishers :) That's cheating! Maybe I need to hook up a pair of my (patented) nuclear-powered beer coolers to each IC? :D

What was the power at the wheels?

what mods do ya have 51x??

 

sounds good for your first test!

What was the power at the wheels?

Whatever you want it to be - it's all guesswork / voodoo anyway ;) I /knew/ you were gonna ask that :) It looks like around 290 at the wheels. Auto-box's eh? BIG drivetrain loss! I reckon Pete left the handbrake on :p

 

FASTREDZ... try http://rides.300zx.co.uk/rides/1204/index.html

It's a bit out of date (the engine's /definitely/ back in now!) but you get the idea. The "1000 bhp @ 100 rpm" is a joke, in case anyone asks.

What? Is that right? Thats like nearly 33% loss. Thats what 4WD Autos systems lose not RWD autos.

Does sound like a lot dunnit? I'm just going by the super-high-resolution printout I have here. Dunno what loss percentages for other autos at EA were on the SE RR day, but I'm sure they were 100+ bhp. I've got another place kindly offering to dyno it soon, so we'll see how it compares on theirs.

Whatever you want it to be - it's all guesswork / voodoo anyway ;) I /knew/ you were gonna ask that :)

.

 

Sorry mate, but thats the wrong way round - the dyno measures the wheel horsepower, and transmission loss is then added to that figure to give flywheel hp.

TBH 130+ transmission loss sounds horrendous. As a comparison, my manual made 400bhp/ 350 atw when it was dynoed - thats only 50bhp loss. And when it was poorly sick at the SE dyno day and made 358/ 305 atw - same tranny loss (give or take a couple of brake, after all there were 3 fat *******s in the boot at SE ;) )

Glad to hear your cars getting sorted Si (at the expense of mine) ;) Pete has now promised next Wednesday (LOL) he's been saying that for 3 weeks now. I left the car there as the no point taking it till it's finished. Although I am not expecting power miracles from it just yet, just as long as the cars quick and not detting will do for now.

 

That RR place in Witham seemed to measure quite low RWHP figures. Mine was 310 RWHP and around 390 FWHP.

 

Up @ SCA in Norwich the car measured around 350 RWHP and around 385 FWHP. (With loadsa of det) :(

 

Think all this power thing is just getting weird. Maybee some fast quaters and top speeds will start proving the fast cars (and good drivers). :)

 

Edds.

Adam - yeah, appreciated it's back-calculated to the flywheel, but my point is that both seem to be so variable based on where you go. OK, I got it wrong about EA reading low - maybe it reads rear-wheel a bit low, then they over-compensated the flywheel figure for autos and under-compensate for manuals. From hunting around for pics of other peoples plots, that seems to be the general theme. So it'd be a bit naff to say: I've got sh*t-loads of bhp at the flywheel (which I'm not) when the drivetrain loss figures look... um... daft.

 

Fat?! Big-boned ;)

 

I started the thread so people would stop ringing me, asking how it came out :) They're the numbers, but the only thing that's really important is how much they'll change after the next session. I think it's a good start, and I'm glad they're using the same loss figure as the SE RR day because it's kinda like I eventually made it, even though I was 4 months(?) late.

 

Forget the flywheel figure... I'm thinking the interesting stuff is where it's making peak bhp (bl**dy high) and peak torque (rather low)! You gotta see how strange the plot looks too, so thanks to Martin for scanning it, you now can. High rpm peak bhp I can sort of understand - that's the cams, innit!? But I'm surprised the the torque mountain looks like that - T28's supposedly having a bit more lag. 1 bar just isn't enough!

 

Dave - sorry about jumping in there, but it kinda felt like it *must* be my turn by now.

Is that it?! No more comments?!.. after we went to the effort of breaking down the front door to Martins work-place just to get you guys a scan of the plot?! You lot are a funny bunch at times :p

nice one mate :) at last you have something,

 

what do you think it will be peaking at when its tuned properly on optimax running full boost? and when is that moment coming?

Yeah, man! It's just great to have /something/ even if it looks like the tranny loss might be wrong.

 

Peak-wise... I really dunno. Pete's saying he was struggling to get it to run nice above 1 bar on 95 RON, but the proper power cars are mapped running Optimax or SuperUL anyway. There's a red car there with the same spec engine / turbos as mine (except uprated rods) and they've recently got ~540 (flywheel) out of it... on Optimax of course. It's running a dual-POP which might help. If mine can't make much better power with a single, it'll probably end up with one.

 

When? I'll be dropping in there tomorrow morning, so we'll have to see how much time Pete can give it. My bloke with the other rolling road has finally got his new software sorted out, so hopefully I'll get a run on that some time soon (this week / next week?).

 

You coming out for a spin Mike? Make sure you've got a clean nappy on - this could get messy ;)

:duffer:

Yeah, man! It's just great to have /something/ even if it looks like the tranny loss might be wrong.

 

Peak-wise... I really dunno. Pete's saying he was struggling to get it to run nice above 1 bar on 95 RON, but the proper power cars are mapped running Optimax or SuperUL anyway. There's a red car there with the same spec engine / turbos as mine (except uprated rods) and they've recently got ~540 (flywheel) out of it... on Optimax of course. It's running a dual-POP which might help. If mine can't make much better power with a single, it'll probably end up with one.

 

When? I'll be dropping in there tomorrow morning, so we'll have to see how much time Pete can give it. My bloke with the other rolling road has finally got his new software sorted out, so hopefully I'll get a run on that some time soon (this week / next week?).

 

You coming out for a spin Mike? Make sure you've got a clean nappy on - this could get messy ;)

will see you there bud , will be good to see this beast of yours

 

Ryan

Excellent! I'll bring me banjo and we can have a quick jam before I have to shoot off to work ;) I s'pose that means I'd better get it washed on the way home tonight or you'll be trying to look at it through an inch-thick layer of dirt!

Excellent! I'll bring me banjo and we can have a quick jam before I have to shoot off to work ;) I s'pose that means I'd better get it washed on the way home tonight or you'll be trying to look at it through an inch-thick layer of dirt!

ROFL ;)

I thought I add my views on this. People make too much of peak figures when that's all they are. There ok for bragging rights and pissing competitions but that about it.

You don't not drive at peak bhp all the time infact hardly ever. You should be more interested in the torque and where it is as that is what you feel push you in the seat, and the power under the curve.

The car IMO is bloody awesome, it pulls very hard before it's even come on boost and it's a constant surge for torque throwing you down the road and trying to rearrange your internal organs .

Much more linear that I had expected it to be and there doesn't seem to be any noticable lag or let up of acceleration. It is seriously impressive :)

 

Si I'd wash it mate as I reckon that layer of dirt is costing you at least 20 at the wheels ;)

Dude! I hardly /ever/ don't not drive at peak bhp. Do I?! No... hold on... I do! :confused: The way it's looking at the moment, it'd be flippin difficult to drive it around peak bhp cos it'd need to be changing gears at somink like 8K! :eek:

 

Glad you liked the torque. It's alright, innit!? :)

 

20 at the wheels maybe... probably a lot more in US bhp ;)

Nice one Simon,if Peter can map it like the other one that's there running 540

Add some NOS, and run it on race gas and you would not be that far behind the big mouths over the pond;) :dance:

LOL! Careful mate, or you'll get Mr Groves jumping all over you for not being sensible. Or does he only do that on his own threads? :)

Dude! I hardly /ever/ don't not drive at peak bhp. Do I?! No... hold on... I do! :confused: The way it's looking at the moment, it'd be flippin difficult to drive it around peak bhp cos it'd need to be changing gears at somink like 8K! :eek:

 

Glad you liked the torque. It's alright, innit!? :)

 

20 at the wheels maybe... probably a lot more in US bhp ;)

 

 

No you don't, but it's always a bit hard to tell with my hands over my eyes :D

 

The reason the car is making the peak power so high is down to the torque curve. You wiil keep making more bhp as the revs rise until the point where the torque curve is droping faster than the rpm's are rising. You can see it on the plot.

 

It's ok to take it up there as long as the valve train can handle it. Not sure what valve spring you have in there or whether there still the original ones. Whats the stock rpm limit on a Z?

 

You don't want to be reving that hard if the valve springs aren't up to it. They have got to be able to close the valves quick enough or you'll end up with valve float and that's not something you want to have.

I'm sure SE have taken all this into account when they built the lump.

I thought you generally stuck your head between your legs, ready to kiss your ass goodbye?! ;)

 

Stock Z rev limit is 7200, I think. Obviously, that's Nissan playing a bit safe. But, as you say, if the valve springs are getting old and sloppy then it'd sort of make sense not to rev the nuts out of it. I've only really seen the heads in a million pieces and everything was spotless then, so I dunno whether the springs are new or not. I'll ask when he's back here later.

 

I'd like to see the torque-curve a bit wider if anything. Hopefully that'll happen running more boost rather than strangling it at 1 bar. Of course, if torque's not dropping off so fast, that's gonna equate to more bhp at higher revs... but we're not worrying about peak values are we? ;) It's quick now. But running better fuel and more boost, it'll be quick-er.

 

How's the ass-dyno now? Are all your guts back where they should be? :D