GT350 vs. Z/28

[thePill]

Stop making up numbers to try and justify your findings. There have been many z28 Dynos making 450 rwhp, so how is it getting 460-480 with a restrictor? Show me one proof of that. Just admit you don't have the answer.

Neither Boss 302, z28 or GT350 use OEM configured engines in CTSC.

Initially, when Grand Am still owned it, the Boss 302R WAS near stock. Even the factory aero was used...

Soon after, the Boss 302R was configured to GS specs and became the Boss 302R1. It began to acquire Boss 302S aero and transmission.

The PCM's were tuned up to use IMSA 100 Octane fuel.

The 444hp Boss 302 makes around 460HP with no cats, no exhaust plates and IMSA 100 tune.

The 505hp z28 makes about 530+HP with the same authorized changes...

A 530HP LS7.R (actual name of the engine I believe) would produce around 470RWHP with drivetrain losses and a small 80mm restrictor (10mm down from 90mm throttle body).

These engines are no longer stock, I hate when they tell people that...

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[thePill]

Re read post 2867.

How about I don't...

Right now, the GT350 is the closest to stock weight than any other car out there.

It also acquired a 58mm restrictor on an 84mm TB right off the bat.

In as little as 2 weeks, the GT350 aquired the same balancing measures as the z28 did in 1.5 seasons or roughly 15 races...

 

[BaylorCorvette]

What we're seeing here is an issue from Grand Am being absorbed by CTSC and trying to balance everything. As i initially said, the sport in evolving. Manufacturers are building sweet flagship vehicles and people want to see them in actual racing which is why we're seeing the Z/28.R and Shelby GT350R-C. One of two things is going to happen, other manufacturers are going to be entering new cars (think BMW M4, Porsche 911, etc.) OR as you mentioned Pill, manufacturers are going to pull out and it will just be Chevy vs. Ford. But I have to think Porsche sees how well Rum Bum is doing with the current Porsche, a 911 would really do well.

 

[thePill]

What we're seeing here is an issue from Grand Am being absorbed by CTSC and trying to balance everything. As i initially said, the sport in evolving. Manufacturers are building sweet flagship vehicles and people want to see them in actual racing which is why we're seeing the Z/28.R and Shelby GT350R-C. One of two things is going to happen, other manufacturers are going to be entering new cars (think BMW M4, Porsche 911, etc.) OR as you mentioned Pill, manufacturers are going to pull out and it will just be Chevy vs. Ford. But I have to think Porsche sees how well Rum Bum is doing with the current Porsche, a 911 would really do well.

Yes, IMSA is slowly changing the class definition and it seems odd with the 997, Boss, M3 and 370z still competing.

These changes were not implemented by Grand Am, it was changed by NASCAR after they took full control in 2011. The Boss 302R was upgraded to the 302R1 rather quickly, less than a season I think.

NASCAR permitted the z28 these freedoms and now IMSA has allowed the GT350.

BMW, Porsche, Nissan and Aston Martin will not return...

This is how you piss manufacturers and the teams that invested money into those cars completely off.

Two major organizations are at fault...

Chevy for not putting direct effort into the class and using their relationship with NASCAR to make this happen.

NASCAR for approving the z28 in CTSC GS to begin with.

Ford has answered the z28 with authority, I can't blame them for the over-effort here. I'm kinda bummed IMSA smashed the GT350 like they did but let's face it, they smashed the z28 too... it just took them longer to react because the z28 wasn't doing super great.

IMSA sees BMW and such leaving, and I didn't expect Ford to make the Mustang GT compete against the z28. Although, it seems Ford is using the GT in PWC GTS.

That's all they really need to be honest...

 

[02gtnh]

Neither Boss 302, z28 or GT350 use OEM configured engines in CTSC.

Initially, when Grand Am still owned it, the Boss 302R WAS near stock. Even the factory aero was used...

Soon after, the Boss 302R was configured to GS specs and became the Boss 302R1. It began to acquire Boss 302S aero and transmission.

The PCM's were tuned up to use IMSA 100 Octane fuel.

The 444hp Boss 302 makes around 460HP with no cats, no exhaust plates and IMSA 100 tune.

The 505hp z28 makes about 530+HP with the same authorized changes...

A 530HP LS7.R (actual name of the engine I believe) would produce around 470RWHP with drivetrain losses and a small 80mm restrictor (10mm down from 90mm throttle body).

These engines are no longer stock, I hate when they tell people that...

These are the GTS class rules. Do you really think they will allow cars over the wheel hp? That means there breaking there own rules. Every other car in the class would protest and not race if this was allowed. This just doesn't happen in sanctioned racing. I raced off-road for years and they were very strict on engine size, so I can't see a program like this breaking its own rules.

2.1.3.2: Grand Touring Sport (GTS)
The allowed body styles within this class are coupe, sedan and convertible. The cars permitted in GTS are typically marketed as “sports cars”, “sport- touring cars” or performance versions of “luxury” cars but at a lower permissible preparation level than GT. Forced induction is permitted on cars that come equipped with forced induction stock. Power output ranges from approximately 300-400 Wheel hp.
Weight varies depending on power output and tire size. Front- wheel, rear- wheel, and all-wheel drive configurations are permitted.

 

[thePill]

ALL REPORTED FIGURES ARE RWHP. Including the 425 @ 43mm.

Get this straight now please, a stock LS7 Dynos at 450, the 80mm restricted LS7.R (530+HP) Dyno's at 470... The OEM z28 IS NOT going out-dyno the 80mm restricted LS7.R.

And shame on you for believing a 10mm restrictor is going to take 50-70hp from the engine. The 43mm restrictor is probably responsible for 50hp but not 100-120HP.

You might lose 5-10hp with a small 10mm restrictor on a 90mm TB.

 

[thePill]

OEM Boss Dynos at 380-390, the 302.R was around 400 with the original 62mm restrictor (18mm). It should be able to make 405-415 without, as in, what they currently run right now.

Your saying an LS7 with an 80 on a 90 loses just as much power and more from an 8mm smaller restrictor right?

Your also saying a 10mm restrictor has a great effect on output in a 90mm TB. That is not the case... A 5 liter engine using an 80mm TB with a 62mm restrictor will net you a larger loss.

Why does physics always work against the Camaro? It's like every action they endure is emotionally devastating. Rain has a great effect on Camaro tires than everyone else. Elevation has a greater impact on Camaro engines. Restrictions are always unfair in a Camaro...

 

[thePill]

I think I've heard enough about "Pushrod Geometry" and "Power to Engine Weight Ratios".

 

[02gtnh]

ALL REPORTED FIGURES ARE RWHP. Including the 425 @ 43mm.

Get this straight now please, a stock LS7 Dynos at 450, the 80mm restricted LS7.R (530+HP) Dyno's at 470... The OEM z28 IS NOT going out-dyno the 80mm restricted LS7.R.

And shame on you for believing a 10mm restrictor is going to take 50-70hp from the engine. The 43mm restrictor is probably responsible for 50hp but not 100-120HP.

You might lose 5-10hp with a small 10mm restrictor on a 90mm TB.

I like how you give the z28 such huge hp jumps from stock, yet not with the Boss. Then you say the site shows 425hp with the Z28 and that is fact for rwhp, yet they show 480hp for Boss and they are wrong. They also show the reg Camaro at 415hp with a 48mm restrictor and yet it only has 426hp stock at the crank. So when numbers favor your theory there right, but when they don't, then the info is wrong.

 

[02gtnh]

OEM Boss Dynos at 380-390, the 302.R was around 400 with the original 62mm restrictor (18mm). It should be able to make 405-415 without, as in, what they currently run right now.

Your saying an LS7 with an 80 on a 90 loses just as much power and more from an 8mm smaller restrictor right?

Your also saying a 10mm restrictor has a great effect on output in a 90mm TB. That is not the case... A 5 liter engine using an 80mm TB with a 62mm restrictor will net you a larger loss.

Why does physics always work against the Camaro? It's like every action they endure is emotionally devastating. Rain has a great effect on Camaro tires than everyone else. Elevation has a greater impact on Camaro engines. Restrictions are always unfair in a Camaro...

We're talking 43mm not 80mm restrictor. Stay on the same page. I already said the 80mm is at 470 crank hp. That 80 is 12% smaller then stock. And yes that can make a difference. The engine is getting 12% less air, you do that to any car and you will feel the results.

 

[thePill]

I like how you give the z28 such huge hp jumps from stock, yet not with the Boss. Then you say the site shows 425hp with the Z28 and that is fact for rwhp, yet they show 480hp for Boss and they are wrong. They also show the reg Camaro at 415hp with a 48mm restrictor and yet it only has 426hp stock at the crank. So when numbers favor your theory there right, but when they don't, then the info is wrong.

OEM Boss 302 444hp, Boss 302.R about 460hp

OEM z28 505hp, z28.r about 525hp (LS7.R)

Boss 302 16hp difference
Z28 20hp difference

One had a 62mm restrictor on an 80mm TB, the other an 80mm restrictor on a 90mm TB.

I'd say the LS7 is 525+

That 480hp was a typo, with a 60mm restrictor that's almost 500hp stock. That's a fantastic jump from 444.

 

[thePill]

We're talking 43mm not 80mm restrictor. Stay on the same page. I already said the 80mm is at 470 crank hp. That 80 is 12% smaller then stock. And yes that can make a difference. The engine is getting 12% less air, you do that to any car and you will feel the results.

Just be aware, that 415hp Camaro engine could very well be the GMP 525hp LS3.R. It is used in racing quite often...

Looking at the numbers, I'd say 415 is from the GMP LS3. It has a similar result with the same 43mm restrictor. But, as I said, the 6.2 suffers more from the same restrictor vs. the 7 liter.

 

[thePill]

A perfect example of following the rules? Aston Martin.... Yes they got a big weight allowance but they comply pretty much. Note the same typos here and there, this looks to be common (4.8 liter and wheelbase is 0.1 off).

Here is an unrestricted Vantage with a 4.7 V8 making 368 REAR WHEEL HORSEPOWER.

Here is the factory car...

We simply don't know how much is lost in the drivetrain. I can tell you it's more than a solid axle Boss 302.

For sure, the z28's 425hp is RWHP, they wouldn't force the Camaro into a 350RWHP situation with 3400lbs.

Next, the regular Camaro is either the 525hp LS3.R with a 43mm restrictor or the restrictor is wrong. I'd say 415RWHP is pretty accurate at 3300lbs.

The Boss 302 does NOT make 480RWHP. Maybe 408 but with a 60mm restrictor, it's cutting it close. Keep in mind, both 302R, 302R1 and 302S engines are all around 400RWHP with a 62mm restriction. Both R and S was mandated to wear one right at the start. Mostly BMW's doing in Grand Am.

 

[thePill]

I'm not sure about SCCA, but IMSA has ALL competitors (CTSCC & Tudor) send their motors to the NASCAR technical center in Charlotte for engine dyno verification.

No, they pretty much leave it up to the manufacturers, teams and their own Technical Director.

Ford actually provides the data to IMSA, there are huge penalties for this. In fact, IMSA makes the manufacturers (of parts too) to provide full technical data.

It is up to the Teams to prove to the Technical Director that the car is in spec. This is every specification, not just RWHP. If they are hiding something, the teams pay the price and the manufacturers get a pass.

This is why a 450RWHP z28 bothers me... The class maximum HP rule is the hardest one to waiver. Somehow the z28 manages to avoid this rule altogether.


...and that 405RWHP Max defined the class more than anything else. Tudor GT starts at 450RWHP.

 

[02gtnh]

Of course, you didn't think my profile pic was accurate? My face photoshopped to a Calvin Kline Advertisement.

I'm sure you probably don't care for this but, there is a nearly nude photo of thePill on SVTP. In the "Body Fat" thread in General :lol:

If I would have beaten my injuries, I would have started boxing in 2013. I held my BMI and weight for almost two years. I lost a lot of weight to try and compete in Super Welterweight... as well as Am Motorsport.

It was not to be :(

But yeah, that's really me... the old Joker pic was me as well, just photoshopped.

If that pic of the old man is you like you said, you got some serious photoshop skills. :hail:I would like to see the original.

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