Took my 91 ZR-1 to the dyno today - ZR-1 Net Registry Forums

Neat · 09-03-2018

Made a trip to RPM Motorsports in Garner, NC today to strap my 91 ZR-1 to a dynojet 224 chassis dyno.

We made 3 pulls with the power key set to "full" and one pull with it in "normal" mode. The car made 371 RWP / 354 RWTQ on the third pull. All three pulls were within a couple HP of one another. With the valet key on sissy mode, the car only made 239 RWHP. Over a 100 HP difference, it was pretty wild to see the difference quantified like that.

It's kind of a weirdo car in terms of mods; it has:

DRM intake cams
Extrude honed plenum
Haibeck chip
Borla catback

It's still on the stock exhaust manifolds and catalytic converters, which is probably holding it back some. Overall though, I'm very pleased with the car.

PS - the guys at the dyno had never seen an LT5 before. They were impressed with the car, and were shocked when I showed them they could turn off 132 RWHP with the little key in front of the shifter.

Here's a video, the car sounds amazing in my opinion:

https://www.youtube.com/watch?v=WGcS...ature=youtu.be

I was sort of surprised / impressed by how little the engine moves when making a pull. It was ran from 2000 (or so) to 7K, and if you watch the engine in the video it doesn't wiggle, rare up on the drivers side, nothing. With no audio and not being able to see the back tire, I don't know that you could tell the car was even running.

lfalzarano · 09-04-2018

I tried to use them for work on my Z, but they are only interested in add-ons and not maintenance.

Lou

Neat · 09-04-2018

I used to work there 5-6 years ago, I’m still pretty good friends with the crew there. The older stuff is definitely outside their comfort zone; they don’t have any of the gear to flash chips, data log OBD1 stuff, etc... Primary focus is LS stuff for sure.

Ccmano · 09-04-2018

Nice... tho the extruded honed Plenum doesn’t accomplish much. You really need a full top end porting of the plenum and injector housings to get the most out of it. Even with the stock exhaust manifolds your set up (properly ported) should be around 400rwhp considering you have cams.
H

Neat · 09-04-2018

Quote:

Originally Posted by Ccmano

Nice... tho the extruded honed Plenum doesn’t accomplish much. You really need a full top end porting of the plenum and injector housings to get the most out of it. Even with the stock exhaust manifolds your set up (properly ported) should be around 400rwhp considering you have cams.
H

Just want to be sure you and I are on the same page: The car only has intake cams, the exhaust cams are stock.

You still think it'd pick up that much with the port work on the intake?

Ccmano · 09-04-2018

Yes I do. Based on my observations, generally, LT5’s with Plenum/IH porting, headers and a good tune get in the 390’s. Add head porting and a light flywheel and they are in the 415-425 range. (Rwhp)

Your combination (without headers) with proper Plenum/IH porting and a custom tune should get you at least 20hp. There was a write up about Extrude Hone here somewhere a few years ago. It was found that it did not significantly open the plenum runners. Let alone the injector housings that can be opened considerably. While some have gone farther, current thinking is to open the Plenum, Injector housings and into the head to 36mm for both primary and secondary runners.
H

Neat · 09-04-2018

I’ve read the Haibeck articles on porting, it was something I have always intended to do... For whatever reason though, your comments have moved that particular project a little closer to the top of the to-do list!

LGAFF · 09-04-2018

I have a DRM car w/o the intake cams. The Borla chokes it with a 2.25" resonator choke point, the etrude honing is pretty small, but will compliment an updated port job. With some updated porting, headers and Xpipe to remove the resonator I made 391RWHP

mcich7781 · 09-05-2018

Josh,

Check the DRM invoice. I believe this car was already ported. It got the full DRM 475 treatment, bigger throttle body, porting, intake cams.

Headers were left off at that time for reasons we have already discussed.

Mike.

Sent from my XT1585 using ZR-1 Net Registry mobile app

Neat · 09-05-2018

I’ll do that, thanks Mike!

09-03-2018	#1
Neat Join Date: Apr 2018 Location: Raleigh, NC Posts: 41	Took my 91 ZR-1 to the dyno today Made a trip to RPM Motorsports in Garner, NC today to strap my 91 ZR-1 to a dynojet 224 chassis dyno. We made 3 pulls with the power key set to "full" and one pull with it in "normal" mode. The car made 371 RWP / 354 RWTQ on the third pull. All three pulls were within a couple HP of one another. With the valet key on sissy mode, the car only made 239 RWHP. Over a 100 HP difference, it was pretty wild to see the difference quantified like that. It's kind of a weirdo car in terms of mods; it has: DRM intake cams Extrude honed plenum Haibeck chip Borla catback It's still on the stock exhaust manifolds and catalytic converters, which is probably holding it back some. Overall though, I'm very pleased with the car. PS - the guys at the dyno had never seen an LT5 before. They were impressed with the car, and were shocked when I showed them they could turn off 132 RWHP with the little key in front of the shifter. Here's a video, the car sounds amazing in my opinion: https://www.youtube.com/watch?v=WGcS...ature=youtu.be I was sort of surprised / impressed by how little the engine moves when making a pull. It was ran from 2000 (or so) to 7K, and if you watch the engine in the video it doesn't wiggle, rare up on the drivers side, nothing. With no audio and not being able to see the back tire, I don't know that you could tell the car was even running. __________________ 1991 ZR-1 #769 - Turquoise / black - DRM 475 - 12.2 @ 121 - 1993 Mustang - White / Black - 5.3 Chevrolet Engine - Twin Turbos - Other Stuff - 8.62 @ 156 -

09-04-2018	#2
lfalzarano Join Date: Feb 2011 Location: Clayton, North Carolina Posts: 1,133	Re: Took my 91 ZR-1 to the dyno today I tried to use them for work on my Z, but they are only interested in add-ons and not maintenance. Lou __________________ Lou[COLOR="Red"][B][SIZE="4"][/SIZE][/B][/COLOR]

09-04-2018	#3
Neat Join Date: Apr 2018 Location: Raleigh, NC Posts: 41	Re: Took my 91 ZR-1 to the dyno today I used to work there 5-6 years ago, I’m still pretty good friends with the crew there. The older stuff is definitely outside their comfort zone; they don’t have any of the gear to flash chips, data log OBD1 stuff, etc... Primary focus is LS stuff for sure. __________________ 1991 ZR-1 #769 - Turquoise / black - DRM 475 - 12.2 @ 121 - 1993 Mustang - White / Black - 5.3 Chevrolet Engine - Twin Turbos - Other Stuff - 8.62 @ 156 -

09-04-2018	#4
Ccmano Join Date: Jun 2006 Location: Sparks, NV Posts: 2,843	Re: Took my 91 ZR-1 to the dyno today Nice... tho the extruded honed Plenum doesn’t accomplish much. You really need a full top end porting of the plenum and injector housings to get the most out of it. Even with the stock exhaust manifolds your set up (properly ported) should be around 400rwhp considering you have cams. H __________________ [B]90'ZR-1[/B] #1461 Red/Black Ported Intake, Degreed Cams, OBX Headers & Exhaust, Fidanza FW, Secondary Delete, Custom tune, C6 GS Wheels. Sold [B]08 C6 Z51[/B] Crystal Red Metallic Sold Vararam Intake, Tune, Sold [B]05 C6 Z51[/B] Red/Black Sold [B]90'ZR-1[/B] #1723 Black/Gray Sold but not forgotten [B]91' Z51 L98[/B] White Vert. My First, you always remember your first. Sold.

09-04-2018	#6
Ccmano Join Date: Jun 2006 Location: Sparks, NV Posts: 2,843	Re: Took my 91 ZR-1 to the dyno today Yes I do. Based on my observations, generally, LT5’s with Plenum/IH porting, headers and a good tune get in the 390’s. Add head porting and a light flywheel and they are in the 415-425 range. (Rwhp) Your combination (without headers) with proper Plenum/IH porting and a custom tune should get you at least 20hp. There was a write up about Extrude Hone here somewhere a few years ago. It was found that it did not significantly open the plenum runners. Let alone the injector housings that can be opened considerably. While some have gone farther, current thinking is to open the Plenum, Injector housings and into the head to 36mm for both primary and secondary runners. H __________________ [B]90'ZR-1[/B] #1461 Red/Black Ported Intake, Degreed Cams, OBX Headers & Exhaust, Fidanza FW, Secondary Delete, Custom tune, C6 GS Wheels. Sold [B]08 C6 Z51[/B] Crystal Red Metallic Sold Vararam Intake, Tune, Sold [B]05 C6 Z51[/B] Red/Black Sold [B]90'ZR-1[/B] #1723 Black/Gray Sold but not forgotten [B]91' Z51 L98[/B] White Vert. My First, you always remember your first. Sold.

09-04-2018	#8
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,188	Re: Took my 91 ZR-1 to the dyno today I have a DRM car w/o the intake cams. The Borla chokes it with a 2.25" resonator choke point, the etrude honing is pretty small, but will compliment an updated port job. With some updated porting, headers and Xpipe to remove the resonator I made 391RWHP __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359

09-05-2018	#9
mcich7781 Join Date: Jun 2015 Location: Morris, IL Posts: 176	Re: Took my 91 ZR-1 to the dyno today Josh, Check the DRM invoice. I believe this car was already ported. It got the full DRM 475 treatment, bigger throttle body, porting, intake cams. Headers were left off at that time for reasons we have already discussed. Mike. Sent from my XT1585 using ZR-1 Net Registry mobile app