GT350 vs. Z/28

[thePill]

Magazine Comparison Incoming: 2014 z28 vs. Big Red Z/28.

Chevy again has brought a Boss 302 to compare it to. At least it's a 2013 Boss and not the old '12. According to the article, one of the two Camaro's were wrecked. Embargo lifts Monday.

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[thePill]

Confirmed:

The Z/28.R in Continental Tire GS has been granted a maximum horsepower output of 470hp. This is almost 100hp more than the M3, Boss 302, 997 and 350Z. All in which are around 375hp.

That is retarded... How any Camaro fan finds honor in that is beyond me. I wouldn't show my support for this behavior openly.

There are still Camaro5 members trying to convince people that the Z's are almost identical. With their heads held high...

Edit: The 997 and 350Z make 355hp and 350hp, both cars are about 200lbs lighter than the 375hp Boss and M3. There is talk of another 100lbs weight reduction for the Z/28 as well. I guess this is in fact a sympathy season for Team Camaro. It's nice they get to keep their training wheels on for the entire life of the car. Must be nice to be rewarded for your laziness...

Porsche 997: 355hp @ 3100lbs
Nissan 350Z: 350hp @ 3100lbs
BMW M3: 375hp @ 3300lbs
Mustang Boss 302 375hp @ 3300lbs

Camaro Z/28: 470hp at 3400lbs...

Ugggggg.... Every class they touch literally turns to sh!t...

Anyone still wanna debate the Camaro's effectiveness in road racing? As a Motorsport Chassis Fabricator and Engineer, I am extremely offended. I'm not even sure why IMSA would allow this anyway, regardless or not the car uses non-OEM, Carbon fiber panels, plastic windows, PrattMiller race components... Anyone? Camaro5? No???

@ Norm,

Remember my concern about airflow into the upper grill of the '14 refresh? This is a pretty decent answer to that though. While it isn't as effective as say the traditional Mustang upper grill, this is a clever way to improve said flow. I am actually anticipating a Gallop styled in this fashion. It's a functional, black out bow tie and I think it's really neat. Some could possibly feel it's lame, it may very well even be on that edge. But it functions and is a black out desig. I'm a Horse delete kinda guy anyway... I have always been that way.

To be honest, I am a big fan of the GT500's grill delete. A trend started by the Boss 302's in competition.

Here's Randy taking out the Boss 302... again... against another Camaro. If only they could get this same car to actually race against the Boss... That would have been cool.

I'm hearing the contest is at Barber, I'm also hearing "the z28 would have done better if it wasn't for the conditions". I think it was hot and humid... God... Never the right conditions for Camaro racing.

Here is Al O. discussing how his $75,000, 7 liter 2014 z28 can perform better for one lap, during magazine test than a $40,000, 5 liter Mustang that was developed in 2010. It is merely class ready for most SCCA and NASA classes. The Boss 302 was foolishly developed from the Boss 302R in Grand Am. While the z28 was developed at Nurburgring, under no control measures what so ever... and managed to out pace the now impotent ZL1 by 200 feet. Even though we stopped and started the stop watch when ever we felt like it, our times are official... any one else doing the same thing is unofficial and probably cheating...

We used the Boss 302 because it is faster than the GT500... Randy Pobst says "Learn to Drive".

 

[Trackaholic]

Yeah, that is basically it. You won't see a chassis stitch welded unless the stitches are gradually filled in. Moving from one bead to the other, giving the metal time to cool. I also consider a lap weld a seam weld along with the butt-weld and fillet. Any time you join two mating surfaces together, it's a seam. Once you get under the exterior panels, spot welds are replaced by stitch welds that are joined. Continuious welds are not used since heat is an issue on chassis/safety structures.

The iCar maximum weld length for OEM vehicles is 4 inches. It's been awhile but I believe the coupons were only 4 inches. There is an iCar bead gauge that measures the bead lenght, bead height and bead penetration. On most panels (safety structure included), Continuious welding causes major distortion. It's almost impossible to weld like that and get good results.

Disclaimer: I also have degrees in Collision, Refinishing, Custom Street Rod and Advanced Metal Fabrication

ICAR Certified and eligible for 40 ICAR points. I have not selected my 10 CDs yet (All testing complete, $300-500 per point)

MIG, TIG and Gas for both Steel and Aluminum.

Some of what you say above is confusing to me.

Seam welding implies a continuous seam of weld bead.
Stitch welding implies an interrupted weld bead.

Whether it is a lap joint, butt joint, fillet, etc. has no bearing on the weld type. You could do a fillet joint with a seam or a stitch for example.

Also, in terms of strength and especially stiffness, a seam weld is practically always better. Race cars and high performance street cars might move to a seam weld in order to improve rigidity by creating a better connection between the parts. For example, the updated Nissan GT-R uses seam welds in certain locations to improve strength and stiffness.
http://www.caranddriver.com/reviews/2015-nissan-gt-r-gt-r-nismo-first-drive-review

The primary downside to seam welding is cost, as it takes longer and it is more difficult to prevent warping due to the added heat of the longer weld. It is for these reasons that most automakers will use spot and stitch welding in a street car, rather than full seam welding. In a race car the strength and stiffness improvements of a seam weld are well worth the added fixturing requirements and weld time.

Does this match with what you were saying?

-T

 

[nametoshowothers]

Some of what you say above is confusing to me.

Seam welding implies a continuous seam of weld bead.
Stitch welding implies an interrupted weld bead.

Whether it is a lap joint, butt joint, fillet, etc. has no bearing on the weld type. You could do a fillet joint with a seam or a stitch for example.

Also, in terms of strength and especially stiffness, a seam weld is practically always better. Race cars and high performance street cars might move to a seam weld in order to improve rigidity by creating a better connection between the parts. For example, the updated Nissan GT-R uses seam welds in certain locations to improve strength and stiffness.
http://www.caranddriver.com/reviews/2015-nissan-gt-r-gt-r-nismo-first-drive-review

The primary downside to seam welding is cost, as it takes longer and it is more difficult to prevent warping due to the added heat of the longer weld. It is for these reasons that most automakers will use spot and stitch welding in a street car, rather than full seam welding. In a race car the strength and stiffness improvements of a seam weld are well worth the added fixturing requirements and weld time.

Does this match with what you were saying?

-T

Most seam welds are done as a series of stitch weld when heat and distortion are a concern, so based on extensive experience you can manage distortion with full welds irregardless of what people call them. Welding of cars is like drawing with crayons compared to the painting from the masters. There are plenty of much more exotic welding out there

 

[thePill]

What he said... A body would never leave the factory with gaps between welds. The amount of heat generated from a continuious weld would warp even the thickest steel.

Stitch and moved about 4 inches down or where ever the metal is cool and stitch again. A stitch can be a single bead or as long as 4 inches.

This is actually hard to explain but, it is a technique used to manage heat and keep your heat affected zone small. Most of the time, spot welds are used in thinker gauge steel and where stitching the seams is practiced in the safety structure. Spot welds are technically not a seam weld since they are not done on a joint.

Continuous welds are no good.

I think the confusion is between the term "seam welding" and "continuous welding". Most welding is done at the seam or "joint" depending on the type of weld (Fillet, Butt, Lap). Continuous welds are when a bead is laid down from start to finish. ICAR says any travel beyond 4 inches or the standard coupon is continuous. They are not the same...

 

[Stuntman]

Where did you get those hp figures?

 

[FATTBoss]

Where did you get those hp figures?

I was wondering the same thing! I thought somewhere many pages ago we all had pretty much agreed HP was probably 400-425 given the 100 octane fuel, some getting aftermarket PCM, and Nissan is even allowed a different head. I would think 400-425 would be a better guestimate than numbers given above.

 

[Norm Peterson]

@ Norm,

Remember my concern about airflow into the upper grill of the '14 refresh? This is a pretty decent answer to that though. While it isn't as effective as say the traditional Mustang upper grill, this is a clever way to improve said flow. I am actually anticipating a Gallop styled in this fashion. It's a functional, black out bow tie and I think it's really neat. Some could possibly feel it's lame, it may very well even be on that edge. But it functions and is a black out desig. I'm a Horse delete kinda guy anyway... I have always been that way.
...

Have to say I like that treatment, especially when the re-interpretation has a technical reason.

Unfortunately, they'll probably sell them by the gross to the lawn chair & crying doll set who won't ever get within 75 mph of needing them :thumbdown:

I've got some history of removing or blacking out bright trim and removing make or model lettering, but for some unknown reason I've left grille emblems mostly alone. Repainted one once, but that's about it.


Thanks for posting a little experience-based welding tech. Most of my career was spent in industries where lots of welding was involved (shipbuilding and nuclear power plants), but I never really got into the nitty-gritty of the processes or the inspections themselves on the job. On my own, well, I can stick a couple of pieces of metal together and they seem to stay that way, but it's generally not pretty and probably wouldn't pass an exam. I've just never done enough of it at any one time, and properly welding any of the high strength steels being used in car structure these days will probably remain outside my ability.


Norm

 

[Stuntman]

I was wondering the same thing! I thought somewhere many pages ago we all had pretty much agreed HP was probably 400-425 given the 100 octane fuel, some getting aftermarket PCM, and Nissan is even allowed a different head. I would think 400-425 would be a better guestimate than numbers given above.

Don't forget the 370 is allowed an aftermarket long tube header. Thepill seems to continue to make things up as he goes along, including "confirmed" HP figures.

As far as the welding semantics go, all Conti cars are welded along the seams in an intermittent stitch pattern By the teams which is beyond what is welded on the factory production line, to increase the chassis stiffness for racing.

 

[FATTBoss]

Don't forget the 370 is allowed an aftermarket long tube header. Thepill seems to continue to make things up as he goes along, including "confirmed" HP figures.

As far as the welding semantics go, all Conti cars are welded along the seams in an intermittent stitch pattern By the teams which is beyond what is welded on the factory production line, to increase the chassis stiffness for racing.

The 470 claim was made here: http://racer.com/index.php/imsa/continental-challenge

Stil not sure where the other figures come from...

 

[Stuntman]

Couldn't find it in that link. Fwiw, "official" numbers are never given and only the teams who dyno their own car and the series who dynoes them occasionally at the track know for sure.

Since street M3s with similar modifications and 93 pump can make around 400hp at the tire (and a bit over on race gas), the major unknown is the impact of the mandated restrictor.

 

[Sabre]

Couldn't find it in that link. Fwiw, "official" numbers are never given and only the teams who dyno their own car and the series who dynoes them occasionally at the track know for sure.

Since street M3s with similar modifications and 93 pump can make around 400hp at the tire (and a bit over on race gas), the major unknown is the impact of the mandated restrictor.

I think this is 100% correct. It's always been my understanding that only the team/engine builder and the series know the true HP numbers. We can speculate and probably be fairly close, but the real numbers are kept private.

 

[FATTBoss]

Can you imagine the crying and whining from the teams if IMSA did publish the HP numbers?

 

[FATTBoss]

Just asked a buddy who races in IMSA and he tells me GS is 400-450. Since Camaro is heaviest, 470 may be correct.

 

[thePill]

The Rulebook still says 400hp maximum as do most teams. A 15mm restriction should take a 505hp LS7 down to that 470hp level. The M3 and Boss 302 are close to a 40% restriction...

470hp... Uh..... It may not be like that for long.

The Mustang's 90mm TB has a 57mm restrictor. That should be a 33mm restriction... The LS7 lost 35hp from a 15mm restriction...

A 33mm restriction would be at least twice that, probably greater on a smaller displacement. It isn't over 400hp, it never was... ever...

Both Nissan and Porsche power levels are near OEM. Around 345-355hp... as per the Rulebook but, both have a lower race weight.

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