1990 #2180 Dyno pull - ZR-1 Net Registry Forums

ghlkal · 07-22-2013

If these numbers are accurate, I'm a happy camper

RWHP 337
"corrected for temp/humidity/pressure" = 353

RWTQ 320
"corrected" = 335

(both at a whopping 5500 RPM or so)

They had some issues loading it on the dyno and by the time they were ready, the car was already pretty hot. I tried to convince him that redline was a little higher too ...

There was only one useful pull, and here are the sheets

The techs hadn't seen an LT5 in person, although several knew about it.

The only "mods" I have are Corsa exhaust and SLP claw intake. The engine runs great after I replaced the fuel injectors.

OK, gurus ... let me know your thoughts. Is this thing really 400HP at the crank?

LGAFF · 07-22-2013

yep, corrected thats 400-410 crank

PhillipsLT5 · 07-22-2013

HP was still climbing at 5653 RPM

ZZZZZR1 · 07-22-2013

Quote:

Originally Posted by PhillipsLT5

HP was still climbing at 5653 RPM

I agree.... He heard the LT-5 roar and got scared!

shame he didn't take it further.

David

Karl · 07-22-2013

That's the same type of dyno (at least the website on the printout) that I ran my '92 on. The operator took my LT5 to the same rpm before shutdown.

Good numbers. With headers and a chip I would guess you will hit 370whp no problem!

LGAFF · 07-23-2013

Time to get headers and a ported top end....

ghlkal · 07-23-2013

Quote:

Originally Posted by ZZZZZR1

I agree.... He heard the LT-5 roar and got scared!

Yup ... it got a little loud in there

http://s517.photobucket.com/user/Nat...aacb0.mp4.html

(I haven't hosted a video on photobucket before, so I'm not sure this will work)

XfireZ51 · 07-23-2013

My thoughts exactly. Power peak is too low. The WCF means With Correction Factor, but which one? SAE, Standard?

Paul Workman · 07-23-2013

Strong numbers, to be sure.

Researching dyno calibration specs a bit, it appears (cutting to the chase) that a 4% variance exists between STD & SAE correction factors, stemming from the fact that SAE normalizes to 77ºF whereas STD normalizes to 60ºF

Also, the SAE 1349 spec requires correction for torque, relative to the mechanical efficiency (ME), or estimated at 85% at peak torque ONLY.

It is still a little vague (to me) how ME is affected when the engine is producing other than peak torque, but intuition tells me as counter rotational force (drive train inertia) diminishes, ME increases. The result would be a reduction in calculated hp at those non-peak torque regions of the rpm band.

In any case, the dyno operator was obviously conditioned to lift when his ear told him he'd reached the limit of conventional pushrod motors. The sound of the LT5 screaming past 5500 on its way to 7k+ scares the crap outta some operators, and the unaccustomed as well.

Well...Now that the hook is set, it is time for some FBI top end porting...and then...and then... Yeah, speed is addicting!

P.

LGAFF · 07-23-2013

put it on the real world dyno(track) and see how she does....

07-22-2013	#1
ghlkal Join Date: Jan 2012 Location: Wisconsin Posts: 887	1990 #2180 Dyno pull If these numbers are accurate, I'm a happy camper RWHP 337 "corrected for temp/humidity/pressure" = 353 RWTQ 320 "corrected" = 335 (both at a whopping 5500 RPM or so) They had some issues loading it on the dyno and by the time they were ready, the car was already pretty hot. I tried to convince him that redline was a little higher too ... There was only one useful pull, and here are the sheets The techs hadn't seen an LT5 in person, although several knew about it. The only "mods" I have are Corsa exhaust and SLP claw intake. The engine runs great after I replaced the fuel injectors. OK, gurus ... let me know your thoughts. Is this thing really 400HP at the crank?

07-22-2013	#3
PhillipsLT5 Join Date: Aug 2005 Location: Scottsdale, AZ Posts: 2,452	Re: 1990 #2180 Dyno pull HP was still climbing at 5653 RPM

07-22-2013	#5
Karl Join Date: May 2013 Location: Chicago Posts: 980	Re: 1990 #2180 Dyno pull That's the same type of dyno (at least the website on the printout) that I ran my '92 on. The operator took my LT5 to the same rpm before shutdown. Good numbers. With headers and a chip I would guess you will hit 370whp no problem! __________________ 1993 ZR-1 #211 Yellow On Beige Beast #2 1992 ZR-1 #427 Black On Black Sold 1985 L98 Blue On Blue Sold

07-23-2013	#6
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,194	Re: 1990 #2180 Dyno pull Time to get headers and a ported top end.... __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359

07-23-2013	#8
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,708	Re: 1990 #2180 Dyno pull My thoughts exactly. Power peak is too low. The WCF means With Correction Factor, but which one? SAE, Standard? __________________ [SIGPIC][/SIGPIC]Former Membership Chairman Former ZR-1 Registry - BOD 1972 Corvette 4speed base Coupe SOLD long time ago 1984 Corvette Z-51/4+3 SOLD 1992 Corvette ZR-1 Aqua/Gray #474 SOLD 1992 Corvette ZR-1 Black Rose/Cognac #458 2014 Honda VFR Interceptor DX

07-22-2013	#2
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,194	Re: 1990 #2180 Dyno pull yep, corrected thats 400-410 crank __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359 Last edited by LGAFF; 07-22-2013 at 07:27 PM.

07-23-2013	#9
Paul Workman Join Date: Nov 2007 Location: Squires (near Ava MO in the Mark Twain N'tl Forest) - Missouri Posts: 6,493	Re: 1990 #2180 Dyno pull Strong numbers, to be sure. Researching dyno calibration specs a bit, it appears (cutting to the chase) that a 4% variance exists between STD & SAE correction factors, stemming from the fact that SAE normalizes to 77ºF whereas STD normalizes to 60ºF Also, the SAE 1349 spec requires correction for torque, relative to the mechanical efficiency (ME), or estimated at 85% at peak torque ONLY. It is still a little vague (to me) how ME is affected when the engine is producing other than peak torque, but intuition tells me as counter rotational force (drive train inertia) diminishes, ME increases. The result would be a reduction in calculated hp at those non-peak torque regions of the rpm band. In any case, the dyno operator was obviously conditioned to lift when his ear told him he'd reached the limit of conventional pushrod motors. The sound of the LT5 screaming past 5500 on its way to 7k+ scares the crap outta some operators, and the unaccustomed as well. Well...Now that the hook is set, it is time for some FBI top end porting...and then...and then... Yeah, speed is addicting! P. __________________ Good carz, good food, good friendz = the best of timez! 90 #1202 "FBI" top end ported & relieved Cam timing by "Pete the Greek" Sans secondaries Chip & dyno tuning by Haibeck Automotive SW headers, X-pipe, MF muffs Former Secretary, ZR-1 Net Registry

07-23-2013	#10
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,194	Re: 1990 #2180 Dyno pull put it on the real world dyno(track) and see how she does.... __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359

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