Dyno Day

[Paul Workman]

Originally Posted by LGAFF

Might come down to the valve relief being the difference or the coolant injection on Pauls

Well, valve relief, maybe. But, the coolant injection experiment was definitely a bust!

Last year I ran a 12.6 at 117, but my 7200 rev limit cut me off well before the trap. The oil pressure switch ended that day's further experimenting.

This year I ran 13.0 at 115 on 7 cylinders, while laying down a thick vapor trail behind me. Naaa. The coolant injection experiment was not a good idea.

P.

[LGAFF]

It was reported after your run that mosquito counts were down

[XfireZ51]

Originally Posted by LGAFF

It was reported after your run that mosquito counts were down

Lee,

That's why Bob G was able to run as fast as he did. Fewer insects hitting windshield and slowing car down.

BTW, in terms of overlaying Paul's dyno on mine, Marc H will be getting the data file from Paul's session so we can get an accurate compare of the curves and area under the curve. Looking at Paul's sheet, the increments on the two graphs are different.

[sammy]

Originally Posted by Paul Workman

Disclaimer: Keeping in mind it is different (DynoJet) dynos on different (tho similar) days (conditions), its always interesting to compare general characteristics, even if absolute value comparisons have a % of ambiguity.

If I'm not mistaken Dom's specs are (Dom, correct me where I'm wrong and I'll edit this..)

Stock bottom 350
Pete's spec regrind "stage one" intake cam w/ Pete's timing
Stock exhaust cam
Watson 1-7/8" headers
plenum and IH ported by Dom
secondary throttle plates and rods removed
heads ported to Greg V's spec
3" exhaust with SW X pipe
Magnaflow (2.5" in, dual exits) muffs

Dom's final run...



Equipment comparison (my car):

Stock bottom
Stock cams
secondaries removed
SW 2" headers, X=pipe, MF muffs (same as Dom's)
Plenum ported to 37mm, septum (knife edged) and length reduced by 13%
'90 IHs ported to ~36.5mm
Heads ported and relieved by me, incorporating taper along with nuance of designs by Marc Haibeck and Pete P, aka the "FBI" patterns.
cam timing by Pete,
final tuning by Marc

My sheet from a year ago...



Of special interest is the torque curve comparisons, which leads me to believe Dom's car is leaving some hp on the table - more even than A/F/timing might buy. I have my hypothesis, y'll can develop your own.

Interesting stuff. Too bad dyno time is so pricy for us mortals (except apparently those mortals owning pizza joints!) But, kidding aside, it would be interesting to take Pete up on his offer to slap his heads on Dom's motor to ferret out the head variance. There is expense involved with pulling Dom's motor and swapping heads and dyno time. I wonder if the Registry would be interested in sponsoring such an experiment, if the porting specs were revealed. That would be between the Registry, Dom, and Pete. (I'm just playing devil's advocate)

P.

i would invest a cnote towards the expense. hopefully this year will be better and i can get the heads on the black car done and some intake cams

[XfireZ51]

Some more info to take a look at. Speed Inc. was good enough to send me the data files of Friday's runs. There's a compare of the first run on Friday with no additional tuning and the swap in of the SW Xpipe and last run of previous set with MFlow resonator in place. Numbers are very close but look at the AFR. Significant difference. Xpipe appears to have leaned the AFR by almost .5:1 requiring richening of the fueling. There's also a compare of the first run with the final run on Friday and then one of just the final run. If you play with the WinPep7 reader software, you'll find that torque increased in some spots by ~20lbft rw between the first and last run. There's almost a consistent 15rwtq/rwhp between these runs and removing the smoothing shows a Max HP of nearly 430rwhp which I expected.

[sammy]

nice detailed write up of the differences . will show alot of people that they need to retune the car when going to an x pipe from a resonator shows the importance of retuning the car when you make a change before bitching that it doesnt run any faster . how many times have we done/heard that .lol

[Paul Workman]

Originally Posted by XfireZ51

Some more info to take a look at. Speed Inc. was good enough to send me the data files of Friday's runs. There's a compare of the first run on Friday with no additional tuning and the swap in of the SW Xpipe and last run of previous set with MFlow resonator in place. Numbers are very close but look at the AFR. Significant difference. Xpipe appears to have leaned the AFR by almost .5:1 requiring richening of the fueling. There's also a compare of the first run with the final run on Friday and then one of just the final run. If you play with the WinPep7 reader software, you'll find that torque increased in some spots by ~20lbft rw between the first and last run. There's almost a consistent 15rwtq/rwhp between these runs and removing the smoothing shows a Max HP of nearly 430rwhp which I expected.

Looking good, Dom. Welcome to the "500" club!

Now a nice 4.30 gear for the rear, and you can bench race with the best of 'em!


(U know I'm juss pullin yer tail, buddy! LOL!)

P.

[XfireZ51]

Originally Posted by sammy

nice detailed write up of the differences . will show alot of people that they need to retune the car when going to an x pipe from a resonator shows the importance of retuning the car when you make a change before bitching that it doesnt run any faster . how many times have we done/heard that .lol

Brad,

Absolutely. And its not the kind of thing where you buy a tune "off the shelf" either. I spent 2 1/2 hrs on the dyno Friday and so far almost 5 hrs total. And that's just WOT. I've probably burned about 50 cals for this motor so far. Some of the changes are minimal or tweaks. Some more substantial and involving quite a few parameters for driveability, idle quality, and PThrottle.

[XfireZ51]

Very nice day in Chicagoland for mid-November. Had to take car out for a brief playtime. The power is intoxicating. 2nd and 3rd gears pull. You can feel the power on reserve. Just tip the throttle and there's MORE, period.
Torque? Yep!
Banging 3nd gear, the car jumps as tires grab. Still keeping ASR ON with street tires but the Nitto Invos feel pretty good. I find myself looking for unsuspecting GTs, Sti's or M3s. Damn this is fun!!!!!
What's fun is having a ZR-1 with 100k+ on the ODO and not giving a shi* about driving it to keep the miles down.

[4-cam]

Nice job Dom, sounds like all the effort paid off. I'm salivating, reading these threads. It's great having you guys doing all the beta testing, paving the way for us ZR-1 rookies. I need to start ordering parts!