Scarab vs Setback? The true test.

[johnc]

you guys are joking "RIGHT" the reason you set the engine back is to get better weight transfer (read that hook up hard and haul ass) to reduce weight over the front wheels (read that better handling and less muscle to turn the steering wheel) and better balance (read that closer to the magic 50/50 front to rear weight bias) that also means better braking

 

Educate yourself:

 

http://www.amazon.com/exec/obidos/tg/detail/-/0879380713/104-9431438-3196753

[Guest Z-rific]

I just did a quick search and found ( a little to my surprise) that a Viper GTS and 911 GT2 have the same weight distribution of 48/52%.

 

Another suprise? The Corvette Z06 and new 350Z share a weight distribution of 53/47%.

 

Granted, they are all very different cars. But it kinda clouds the whole 50/50 arguement.

 

I read conflicting reports of the Z's weight distribution, so I will not post numbers on that. I'm sure the weight dist. may be different between 240/260/280 as well.

[Guest Nic-Rebel450CA]

Weight distro as a factor of % is also not the best way to consider the handling of the car. For example, a mid-engine and a front engine car can both be setup to have a 50-50 weight distro. I am sure that we can all agree that these cars would not handle nearly the same. You would have to calculate how much weight is before the front wheels, over the wheels, behind the wheels, in the middle, in front of the rear wheels, over the rear wheels, and behind the rear wheels. Then figure how much the weight is above, at, or below the overall center of gravity of the vehicle. I am sure you could go on for quite a while trying to mathematically figure out everything a good driver could figure out by driving the car.

[Savage42]

I would really like to see the results of this test... I'd like to see what penalty the Scarab pays in autocross/lap times for it's better ground clearance.

 

Actually, we've played around with that stuff around here. We have the second largest autocross club next to the Oregon region SCCA in Portland. I've got 2 friends that have done both setups. One has the motor set in the Scarab position, the other went back and low with his LT1. Technically, the weight is still sitting on the motor mounts, and actually has proved to have little affect on how the car handles. A little higher and forward actually gets the car closer to the 50/50 balance. The car that is setup that way is one of the fastest autocross cars in the state and hasn't been beaten by the other with the set back setup, although they are very close. So, in my decade of autocross and car building, I've yet to see any real advantages of one over the other. If there is, it's trival at best. Just my 2 cents.

 

One final thought......I don't think 99% of the Zs out there are so sorted (handling wise) that a change in engine placement way way or the other would make for any real affect. I can see playing with it in a full-blown race car that is just dialed, shock valving and spring rates are perfect, adjustable sway bars, etc. Unless you run the car at 100% and are a top amateur or pro racer, I don't think 98% of Z owners would even be able to feel any difference. It's like when I ran our '70 Cuda factory Trans-Am car at Sears Point and it's at a point when 5-10 gallons of gas significantly changes the handling of the car. Now that's fairly dialed.

[Guest drahgonking]

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[Guest SteveR]

Drahgonking, please read this:

http://hybridz.org/phpBB2/viewtopic.php?t=24170

Particularily #'s 8 and 9

 

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Personally, I don't think it's that big of an issue, because the weight differnence is only slight enough, that you can tune your suspension to suit. It would, however, but quite interesting to see the results. So go ahead and do it and document it well. Especially since you don't stand to lose much in the process.

 

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[Guest zfan]

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[JMortensen]

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[Guest Z-rific]

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[johnc]

Stop! Let's go back to the original thread topic that Art started. If not, the thread's going to be locked and gone.

[spdsk8r]

Thank you, John.

[SportZ2]

These last few posts are exactly why I want to do a basic conversion for a basic baseline test. I never really thought that there would be this much passion for just wanting to do a simple comparison

 

I've gotten enough feedback already to point me in the right direction.

 

A couple of people have contacted me about driving and I will be getting in touch with them after the national convention.

 

I still need to talk to Mike Kelly (could you PM me your phone number so I don't have to search for it. thanks)

 

I understand now that whatever I do, not everyone is going to be satisfied with the outcome and that's ok. But it might help the beginner in making the right choice that best suites their needs. Cost, time, experience, etc.

 

And if nothing else, everyone will have something in print that they can throw at each other while arguing. Just make sure you have an extra copy put away somewhere safe and sound.

 

Later guys,

 

Art

[Guest drahgonking]

sorry to piss everbody off what i was trying to say in the first place is that the people at jtr spent alot of time and money to make a kit that would out perform a scarab i was racing curves in california when most of you were in diapers i have seen what a scarab can do in curves i was not impressed to say the least with a good driver in a really tight curve the rear end would pivot on all that weight on the nose of the scarab and get crossed up alot like a cobra but less power that is why in a repli cobra they have set the engine back it really does help if my gto could beat one in tight curves then they really need help (i am talking the scarab not the cobra) how many of you have ridden in a scarab or a cobra does anyone remember the corvette gran sport the engine was set back in that car closer to 50/50 weight transfer and it stomped shelby cobras i have never seen a zcar that could come close to beating a shelby mustang let alone a shelby cobra please do not get me wrong i love my zcar but to do what you guys were talking about would require dump trucks full money so why waste the money on a theory that has already been proved if you guys want to send me a nasty or mean e-mail my adress is zeecad500@yahoo.com zeecad500 because i put 500 cubic inch cadillacs in my zcars stock 400hp 550 ft lbs of torque and the the distributor is in the front for better clearance also it weighs only 45 lbs more than a small block chevy oh one more thing it accelerates like a cobra (yes i have ridden in a real cobra) so i know what they can do you guys can hook your chevys up to a r200 rear end the 500 cad vaporizes a r200 rearend well sory again for pissing you guys off

[Oltmann]

You seem to be missing a few of these..................................................................................................

[Guest Vashe]

Maybe i am just being ignorant here, but why is the location of the engine by a few inches such a big deal? They both do the same thing, have the same goal. The only i would be interested in seeing is the cost differance, if any.

[johnc]

OK, I'll take the time...

 

> sorry to piss everbody off

 

What you said didn't make folks grumpy, it was how you said it. Just take the time and make a more thoughtful less emotional post.

 

> what i was trying to say in the first place is that the people

> at jtr spent alot of time and money to make a kit that would out

> perform a scarab

 

Maybe, but there's a lot more to handling then weight distribution. Its not the be-all, end-all that most people think. A great real world example is SCCA's Speed Touring where FWD and RWD racer cars are about equal in handling.

 

> i was racing curves in california when most of you were in

> diapers i have seen what a scarab can do in curves i was

> not impressed to say the least with a good driver in a really

> tight curve the rear end would pivot on all that weight on

> the nose of the scarab and get crossed up alot like a cobra

> but less power

 

I think that was a sentence, but I'm not sure. Please, please, please use punctuation and capital letters. You've cited one anectdotal example which was probably true for that car, that driver, on that road. Its probably not applicable anywhere else.

 

> that is why in a repli cobra they have set the engine back

> it really does help if my gto could beat one in tight curves

> then they really need help (i am talking the scarab not the cobra)

> how many of you have ridden in a scarab or a cobra does anyone

> remember the corvette gran sport the engine was set

> back in that car closer to 50/50 weight transfer and it stomped

> shelby cobras

 

The Gran Sport Corvette never won a championship and won very few races. It didn't stomp much of anything during its short racing career. The aerodynamics were so bad that it had horrible understaeer at speed. And why do you keep citing cars from the early and mid-1960s as examples of good handling? We all know Cobras, Shelby Mustangs, and Gran Sport Corvettes were very poor handling vehicles. They made up for their poor handling with gobs of horsepower.

 

> i have never seen a zcar that could come close to beating a

> shelby mustang let alone a shelby cobra please

 

In April of this year my L6 powered 1970 240Z beat a Shelby Cobra Replica, five Z06 Corvettes, two Dodge Vipers, a Honda S2000, a Turbocharged Miata, a fifth gen Supra Turbo, and 52 other cars on seven racetracks over seven days of competition.

 

> do not get me wrong i love my zcar but to do what you

> guys were talking about would require dump trucks full

> money so why waste the money on a theory that has

> already been proved

 

Well, most of us here on HybridZ think its still a theory. Again, that goes back to the idea that there's so much more to making a car handle well then just weight distribution.

 

> if you guys want to send me a nasty or mean e-mail my

> adress is zeecad500@yahoo.com

 

We don't do that.

 

> zeecad500 because i put 500 cubic inch cadillacs in my zcars stock

> 400hp 550 ft lbs of torque and the the distributor is in the front for

> better clearance also it weighs only 45 lbs more than a small block

> chevy oh one more thing it accelerates like a cobra (yes i have ridden

> in a real cobra) so i know what they can do you guys can hook

> your chevys up to a r200 rear end the 500 cad vaporizes a r200

> rearend well sory again for pissing you guys off

 

OK, here's the deal. You HAVE to use punctuation if you want to continue to post here. I just spent 20 minutes going through this one message of yours trying to figure it out. If you want to make points here and educate us, you have to make it easier. Your next post needs to be correctly punctuated, capitalized, etc.

[SportZ2]

Hey guys, started doing my homework and brushing up on the JTR conversion (8+ years since my last one), since most of my prep work will be based on it even for the Scarab. Was comparing my two manuals (3rd printing, Sept 92 and 7th ed., 3rd printing, Feb 01). I noticed that nowhere in the manual does it discuss/compare full header to block huggers. It compares exhaust dia., mufflers, and cast iron exhaust manifolds to headers.

 

JTR puts all it's weight (no pun intended) behind the position of the engine and cooling, telling me that this should be a test of position only.

 

If anything, the only difference I should have in the setup, is that I should use a manual fuel pump on the scarab and an electric fuel pump on the JTR. This will really only effect the cost part of the test.

 

The more I think about it, the more I believe that this is a test on handling, cooling, and rear wheel spin not performance.

 

With the car being the same, the drivetrain being the same, and the driver being the same, these two conversions will finally have a true baseline to compare too.

 

To the people that say this test will be biased toward the JTR if I don't use a full header will actually swing the bias toward the Scarab in terms of performance and that is not the intent of the test.

 

In fact, I find it interesting that JTR says by moving the engine 4" back would be the same as moving the battery to the back and keeping the engine in the Scarab position making the only real difference in the steering of the car (parking as their main reason). But they don't suggest that you do it with their conversion, Why? They've had enough new additions to say it.

 

I will continue to decide the true meaning of this test and let you know what I'm thinking along the way. If you think I'm totally off base with this let me know why, but in a short way.

 

Bare with me as some of my posts will be very simplistic so that the beginner/novice can follow along. I understand that the experts out there will yawn a few times with some of my posts, but hang in there and hopefully the end result will make it all worth while.

 

Started prepping for the removal of the L28 today, so I'm officially on the clock. I will be doing 95% of the prep work by myself, so it will seem a little slow at first. I'm looking forward to this even if it's more work than I need to do.

 

Bare with me as some of my posts will be very simplistic so that the beginner/novice can follow along. I understand that the experts out there will yawn a few times (alot) with some of my posts, but hang in there and hopefully the end result will make it all worth while.

[v8dats]

that was very well written!

[JustAFantaZ]

If anything, the only difference I should have in the setup, is that I should use a manual fuel pump on the scarab and an electric fuel pump on the JTR. This will really only effect the cost part of the test.

FWIW, I used a mechanical pump at first with the scarab, but then when I hooked up NO2, I used an electric fuel pump I bought from Summit. But I'm sure a fuel-injected motor vs a carbed motor would require different electric fuel pumps.

[Guest zfan]

Just a simple question.

 

Where do they come up with the JTR sitting back 4" further back than the Scarab? Only reason I am asking is my scarab with a non HEI distributor/ it's a MSD pro billet, sits 3.5" from the fire wall. With the HEI how the heck can you get four inches?

 

The HEI is much fatter and therefor cannot get much more than 2" from my placement.

 

I'm just curious and not trying to stir the pot, just curious is all

 

Thanks Mike