Apr 15, 2019 update to the Chevrolet Corvette Z06 project car

Project Z06: F.A.S.T. Intake Dyno Results vs. Stock

With 405hp on tap, our C5 Z06 project wasn’t exactly suffering for thrust, but with modern factory Corvettes pushing 450+ up to over 700hp, there’s always room to improve when it comes to the get up and go.

Our first stop on the way to more power was an intake manifold from F.A.S.T., widened with a 92mm opening. Currently we’re using the stock 75mm throttle body with an adapter—since we only like to upgrade and test one thing at a time—but the 92mm opening gives us lots of room to derestrict the intake tract down the line.

Installation was fairly simple, if a bit tight. There’s a couple of fasteners toward the back of the engine bay that will take a while to get out, just live with it. Likewise, installation of the F.A.S.T. manifold is straightforward, but snug. The 92mm manifold is about as tall a manifold as you can get under the stock cowl of a C5 without lowering the engine using shorter mounts or modifying the cowl area using a saw and/or hammer. For clearance, you’ll also have to flip the manifold pressure sensor to face the driver’s side of the car, rather than the passenger side. It’s simply a matter of sticking it back into the manifold facing one way instead of the other.

Since we were disassembling the fuel system anyway, we also took the chance to replace our stock 24lb/hr injectors with a set of Deatschwerks 45lb/hr injectors. While our stock injectors could have kept up with the fuel demands of just an intake manifold change, we were future-proofing ourselves a bit with more modifications in mind down the road. Those stock 24s are good for a few basic bolt ons, but don’t give you much tuning room when you start to get into stuff like long tube headers, and especially more aggressive mods like cams. The Deatschwerks injectors are simple drop-in pieces that fit like a glove and ran perfectly right out of the box.

Our reward for this wrenching and a bit of tuning was seven additional peak horsepower and four additional pounds of peak torque (on a very stingy Mustang chassis dyno). The best part of this graph, though, was the broad-spectrum torque we picked up all the way across the rev range. There was additional torque from the beginning of the test all the way through to the rev limiter. That translates into more thrust where and whenever you hit the gas, and we like that.

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jwagner
jwagner New Reader
4/15/19 2:07 p.m.

Isn't a tune/recalibration needed when you move to bigger injectors?

StuntmanMike
StuntmanMike New Reader
4/16/19 6:36 a.m.

^^^ Like he said, this has to be without tuning right? Numbers seem low, but it is on a Mustang dyno

Patrick
Patrick MegaDork
4/16/19 7:11 a.m.

Can I have the old intake for a challenge car

Andy Neuman
Andy Neuman Dork
4/16/19 8:09 a.m.
Patrick said:

Can I have the old intake for a challenge car

I asked first on the instagram post...

docwyte
docwyte UltraDork
4/16/19 8:41 a.m.

That's a lot of money for not very much gain

Tom Suddard
Tom Suddard Director of Marketing & Digital Assets
4/16/19 8:52 a.m.

In reply to StuntmanMike :

We did re-tune the car after adding the intake and injectors.

 

JG Pasterjak
JG Pasterjak Production/Art Director
4/16/19 10:05 a.m.
jwagner said:

Isn't a tune/recalibration needed when you move to bigger injectors?

'07 MX-5

The answer is maybe. The stock ECM has a bit of leeway, but plugging-and-playing probably won't be a best case scenario. 

We tuned both pre-install and post-install. On our car, there just wasn't much there with tuning alone. This could be due to the age of the motor (nearing 100k), or just the factory tune being fairly good to begin with, but we didn't find more than a couple hp with tuning alone.

JG Pasterjak
JG Pasterjak Production/Art Director
4/16/19 10:06 a.m.
StuntmanMike said:

^^^ Like he said, this has to be without tuning right? Numbers seem low, but it is on a Mustang dyno

A notoriously stingy Mustang dyno, at that. 

AngryCorvair
AngryCorvair MegaDork
4/16/19 10:11 a.m.

were any pedestrians harmed in this testing?

Keith Tanner
Keith Tanner MegaDork
4/16/19 10:19 a.m.

That's not very impressive. 2% gain, pretty much all over 5000 rpm. What's the run to run variation look like on this dyno?

Patrick
Patrick MegaDork
4/16/19 10:29 a.m.
AngryCorvair said:

were any pedestrians harmed in this testing?

No it’s a corvette not a mustang 

DeadSkunk  (Warren)
DeadSkunk (Warren) PowerDork
4/16/19 11:06 a.m.

It will be interesting to see how much power jumps with a larger throttle body. The FAST manifold may not be flowing much better than the stock unit at stock air flow rates , but will do much better with more throttle area.

AngryCorvair
AngryCorvair MegaDork
4/16/19 11:22 a.m.
Patrick said:
AngryCorvair said:

were any pedestrians harmed in this testing?

No it’s a corvette not a mustang 

Ah, but it is a Mustang dyno.  I know we don't drive dynos, but wasn't sure about risk crossover from dyno to vehicle.

93gsxturbo
93gsxturbo SuperDork
4/16/19 12:18 p.m.

There are a ton of articles about LS manifolds because of course there are, and the gist of it is the Z06 manifold, truck manifold, and FAST are all within the statistical variation on those motors.

Until you run big boost or big cam, then the truck manifold and Fast manifold will pull ahead slightly.


That being said the FASTs still look purty.  

JG Pasterjak
JG Pasterjak Production/Art Director
4/16/19 2:37 p.m.
93gsxturbo said:

There are a ton of articles about LS manifolds because of course there are, and the gist of it is the Z06 manifold, truck manifold, and FAST are all within the statistical variation on those motors.

Until you run big boost or big cam, then the truck manifold and Fast manifold will pull ahead slightly.


That being said the FASTs still look purty.  

We've heard this as well. Alone it doesn't do a ton (although we were pleased with across-the-board gains), but it does future-proof us for additional mods.

StuntmanMike
StuntmanMike New Reader
4/17/19 10:00 a.m.

Just noticed you are still using stock throttle body, going with the bigger should give a couple more horses at the peak. Also just going with a "ported" stocker will make it responsive for driving, not sure if it actually makes any more power though. (i say "ported" because it only smoothes out the lip before the throttle plate, not actually opening up the whole thing). Jegs has cheap 92mm cable driven throttle bodies you should throw on there.

Overall its good for future proofing like you and other said, it really comes into play with more mods. Generally the LS6 cant be beat for the money with bolt ons and even mild cams. The truck intakes are better for low torque, especially the newer style street name NNBS/Trailblazer SS/etc. I don't think you can give away the original Vortec intakes anymore. 

kimbo305
kimbo305
4/17/19 4:36 p.m.

> There was additional torque from the beginning of the test all the way through to the rev limiter.

Is the brighter blue line the dyno with the new intake?

Looks like it's below the original engine's torque for <3000 RPM?

Streetwiseguy
Streetwiseguy MegaDork
4/17/19 8:38 p.m.

Times have sure changed.  In 1982, I bought a brand new 5.0 145 hp Z28 Camaro.  About six months later, I voided the warranty with a Comp 260H cam, a new timing set and an Edelbrock performer intake manifold.  I had no dyno, but the engine would then rev freely to 6000 rpm instead of 3500, and it took 1.2 seconds off the quarter mile time...Which was still painful.  Got me into the 16's, I think.  (The car now has a 350 with a small supercharger on it and has run 13.50's.  Thats better.)

Modern stuff is way, way closer to optimized.

 

Keith Tanner
Keith Tanner MegaDork
4/17/19 9:29 p.m.

It's been my experience that it's all about cams on the LS motors. You can dink around with heads and intakes and headers and throttle bodies - but in the end it's all about cams. And displacement. Displacement is good.

JG, you need to look at how much you'll dump into the LS6 versus just buying an LS376/525 crate.

docwyte
docwyte UltraDork
4/18/19 9:19 a.m.

A baby cam on my LS1 added +40rwhp.  That was with the stock "crappy" 243 heads, stock LS6 intake a set of shorty headers.  Everything I did after that including the FAST 92/92, long tube headers etc basically wasn't worth it dollar to hp wise.  Going to a 383 helped a bunch with torque but if I'd put in a top end screamer cam that would've easily blown all the other mods out of the water and kept thousands of dollars in my wallet.

Keith Tanner
Keith Tanner MegaDork
4/18/19 6:31 p.m.

I realize that I recommended an LS swap for an LS powered car. Which has provided me with some internal amusement.

I also realize that JG has to promote the parts sold by his advertisers, and that it's in GRM's best interests to show a bunch of LS6 modifications instead of just shoveling an LS3 in there. But if he was a more typical enthusiast, that is math that should be done.

JG Pasterjak
JG Pasterjak Production/Art Director
4/19/19 12:32 a.m.
Keith Tanner said:

JG, you need to look at how much you'll dump into the LS6 versus just buying an LS376/525 crate.

Oh, very much so. It's math we've done at editorial meetings several times. An LS3-based crate motor with 525hp can be had for under $8000 when they go on sale. Figure another $500 for adapters and tuning. Then we could sell our LS6 for $3500-$4500 fairly easily. 

Believe me, it's come up.

So you'll notice that not much we're doing to this motor can't be recycled onto an LS3 at some point. 

We've also looked into yanking the LS6 and building it from the ground-up, but you;re at $10k before you;re close to teh power and torque levels of a crate LS3, and that's just on parts. Unless there's some magic formula out there we're missing.

So we totally hear you on that, and an LS3-based motor may be in teh future. But for now we do need to cover bolt-on mods for the original motor for folks who can't switch because of rules or don't want to switch because of expense or technical ability.

deaconblue
deaconblue New Reader
4/19/19 3:19 p.m.

JG yes that stock close to 100k mile LS6 engine may need some attention soon.  Just to give you an idea on what can be done and the cost...

The PO of my '99 FRC (a good friend of mine) had cylinder #7 let go on the warmed over stock short block LS1 engine during a road course event back in 2015. Seems that #7 is the one that is most likely to fail in these engines. It doesn't help that the ring gaps on the factory pistons are a bit too tight and the typical elimination of the rear coolant cross over / steam tube when you install the LS6 or aftermarket intake manifolds means those back cylinders and heads run way too hot.  Also the PO had been running a Melling #10296 high volume oil pump, no oil cooler, 5w-30 oil (with an extra quart added) and the early 1-pcs bat wing oil pan and a stock radiator with a 160 F thermostat. He was seeing oil temps as high as 300 F during track event secessions before the engine went south. No idea on what oil pressure reading he may have been seeing.

The PO had Mike Norris Motorsport in Indianapolis replace the engine with a 5.7L TMS stage #2 short block using a stock GM crank in a later 12561168 LS6 block, a set of forged Scat Pro Comp I-beam 4340 rods with ARP 8740 cap screws.  Diamond forged pistons with -2cc valve reliefs (due to high lift camshaft) with their 1.2mm x 1.5mm x 3.0mm ring package and 8620 alloy wrist pins, all blue printed and balanced. Mike installed a Melling 10295 high pressure oil pump and due to the bearing clearances he recommended at least 40 weight oil. He transferred the Comp Cams 226/230  0.598"/0.602" 113+2 LSA camshaft from the old engine and also installed a new LS2 timing chain, new LS7 lifters in new LS2 trays. Mike then topped it off the short block with a pair of reconditioned stock 243 heads and transferred all the Comp Cams valve train pieces / parts from the old heads. He installed new Manley push rods and new GM gaskets throughout including the stock factory later 0.053" MLS head gaskets (I wished he would have used Cometic 0.040" MLS head gaskets to gain back the cc's lost to those valve reliefs in the pistons - oh well). The PO also had him upgraded to FAST 36# injectors at the time as well. Total out the door cost with parts, labor, tax and a full dyno, idle and drive-ability tune was just under of $9.3K. As always YMMV. 

The car also has the '01-04 LS6 85mm descreened MAF and the 78mm LS6 throttle body (75mm was the LS1).  With a Callaway Honker CAI and ceramic coated LG Pro LT header and catted X-pipe with a Z06 Ti exhaust.  Last time tuned she made around 409 rwhp and 392 ft-lbs of torque on a DynoJet.  I have a older FAST 90mm intake and a factory LS2 90mm throttle body with an adpater harness that I would like to install and see what else is left in the combo before the 243 heads go to TEA for their stage 1 CNC porting.  I know you had some issue during your LT header installation, but maybe a fresher engine would yield better results?

The FRC has not seen track duty since the new engine was installed. Before I take her back out on the track though, I will re-install the 4-corner type coolant cross over / steam tube setup to help eliminate any hot spots in the back of these cylinder heads. Following your lead I will also install a HD 2-row fabricated aluminum radiator as well as a thermostatically controlled oil cooler kit (hopefully the new yet to be released Improved Racing kit) to maximize the cooling capacity and keep the fluid temps properly managed. For better oil control, I will also install the Improved Racing trap door baffles in a later '01-04 2-pcs bat wing oil pan, as well as the updated the valley cover and PVC system setup from the '04-05 LS6 and install an Elite Engineering catch can setup. All this to give me hopefully a more bullet proof setup (short of an Accusump or a dry sump conversion) and better peace on mind while out on the track, as well as to help protect the PO's investment in the new engine.

The FRC is also sporting the heavy but reliable factory stock LS3/LS7 flywheel & clutch assembly as well as a '01-04 torque tube.  The next thing that will need looked out in the drivetrain will be the factory stock 79K mile differential.  For hard core track usage a pair of coolers for the trany and differential fluids may also be in the cards.

 

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