V8 Handling question

[Guest Anonymous]

I meant nothing of the kind. I appologize if I implied it was a waste of time or people energy, that wasn't my intent. And if some have swayed one way or the other thats great, I guess I should have qualified it with IMHO first, which I usually try and do.

 

I don't see why there should be a division amongst V8' z'ers anyway, doing such would make one side or the other 'purist' which is something we abhorr at HybridZ.

 

The point I was trying to make, is its all still speculation. Point me to a chassis expert that says moving an engine 3 or 4 inchs forward or back will make little or no difference and I'll be more than happy to read it, and buy into it.

 

Do I believe everything Mike Knell wrote in the book? No, but on this particular issue, I can't see why his claim should be portraited as baseless or less than honest. I'm willing to change my mind if I see evidence, and if you've received mail about it great, then perhaps I missed something.

 

Those that do run Scarab engines will NOT face redicule on this site, read the mission statement, it makes that clear. I not a purist or a brand specific car guy, but just a car guy, whats important to me is that it goes down the road. In my opinion there isn't two fractions on V8' z's (or three if you include MSA's kit), hybrids are hybrids no matter how they're mounted.

 

I will say, that the Scarab position will IMHO have more problems mounting with the newer transmission that have internal linkage (T5, T56), doing so in my application would have put the shift handle nearly in the fusebox and your knuckles on the dash. Some trannies like the Tremec with its three different mounting positions for the shifter might be better suited.

 

Once again, appologies if I offended anyone with my post, it was just an opinion and just like everything else you read here (and on the net), is a Personal opinion based on the person's experience or beliefs.

 

Respectfully,

 

Lone

[Mikelly]

I'm all for tolerance. I'm also all for open ended, thought proviking discussions. I'm also up for a REAL & QUANTIFIABLE Test that would be able to accurately measure the right way to set a V8 Zcar up. Puhn says it best in his book on handling and it is backed up EVERY weekend at every padock in the world. Lower the motor and get it as near 50/50 as possible for road course handling, or best balanced for launch if doing the 1320 shuffle.

 

Does this mean the scarab kit isn't viable? NO. It is still a MUCH better alternative than no alternative at all, which is what we had in 1975. Is it for everybody? No. Is that bad? No.

 

Is the JTR manual the bible? Yes, in my opinion it is. And just like the bible, I use what makes sense to me and scrap the rest.

 

I Hope that EVERYONE HERE realizes that we all have a voice. I'm all for all of us voicing our opinions politely and with civility, be us turbo, straight L6, Buick Huffers, Ford, or chevy V8s. Guys we are all n the same team and that is the bottom line. Mike Knell makes it clear in his book and he make it clear to me when I blasted him for his POOR work in the T56 department... He wrote down only what HE knew to work at the time. Things change, and more information is found... Good for us all...

 

Mike Kelly

[Guest Anonymous]

Lone,

If "if it is all still speculation" why have you formed a definite opinion on this issue, and on what basis did you arrive at it? The belief that "3 or 4 inches" of engine mounting position makes a big difference was forwarded by Mike Knell. What chassis expert did he point to when he made these claims?

 

Mikelly,

A definitive test is simply not possible. I made a list of the similarities between all the Chevrolet V8 equipped Z cars and basically the list looked like this:

1. Nissan products

2. V8 Chevrolet engines

Beyond this, the variations on the conversion theme are as many as there are cars converted. To try to draw conclusions from such a wide diversity of combinations is impossible.

Pure theory forwarded by engineers is merely a point of departure in ascertaining some semblance of what should or should not work "best". The problem lies in the definition of best!

Defining "best" is a complicated equation with multiple considerations, of which race track handling manners can only be one.

IMHO responsibility for supporting some of the claims made in the JTR manual is virtually nonexistent. We are asked to accept what we all agree as "just Mike Knell's" opinion as unimpeachable fact, yet anyone who questions this fact is asked to disprove the assertions. Why does this inconsistency in subjective observation exist in the first place?

Perhaps your reference to the Bible is more appropriate to this discussion. What we are really talking about here is faith. Faith that Mike Knell really does now what he is talking about. That in the writing of this book he really did place a lot of time and thinking into what is "best".

Mr. Knell's statement on page 1-1 regarding his belief that "in the final analysis"..."the car will be done right the first time." is patently inflamatory and an insult to anyone who did their conversion differently.

If we are all kindred spirits here, then why do we allow such rhetoric to go unchallenged? IMO, such statements are a blatant contradiction of the mission statement of this board.

If this doesn't smack of purism I don't know what does.

[Guest RXO510]

Whoa. Alittle intense here for us. We're just learning about the V8Z, but it seems like the JTR manual for now is a great reference point. We had the scarab setup in our Z, but decided to go with the JTR conversion. We used nothing from the JTR kit. We made do with what we had and tried to set it up the JTR way. Just following some of their installation procedure is all. Not because we think that the JTR manual is the bible, but what we read seemed pretty reasonable and in terms we could understand. Setting up our engine this way will enable us to install the T5 or T56 trans later without that many mods, which we're planning to do in the future.

We honestly get lost with some of the posts in here. We just CAN NOT understand some of the technical terms and we're just trying to learn. We wish we knew half the terms sometimes.

This forum has many informative, experienced, willing to share, all out helpful people in here. Thank god, because I was going into the V8Z world without a clue.

I try to read all the posts before I ask questions on this sight. I am amazed everyday with all the info I can get here.

Seems to me everybody does or has tried their own ways of setting up; engines, suspensions, chassis, exhausts....... Awesome! That means we can get more info on the same subject from different views. What's all the hub bub?

To each, their own.

[fastzcars]

I havn't seen such a debate since the chevell forum thing last month. But I do have a scarab car that I'm in the process or converting to JTR specs. The reason I'm changing is three fold. 1. my z currently has a t350 transmission and driving it on the fwy gets alittle buzzy @65mph ,tachs at 3800 rpm. So i got a t56 for the overdrive.2.reducing the rpm will help my engine live a little longer and not heat up ,as easily. 3. the scarab position wouldn't let me mount that long trany in the tunnel, so that the shifter ends up in the stock location.handling isn't too bad, but the steering is heavy, Thats why I have a 15" sparco ralley steering wheel.Thats why I'm switching.Just my 3 cents.Oh by the way OMAR my e-mail service wasn't working right. I think I fixed it, I check tonite. See ya.

[ZROSSA]

Getting tence here fellas. There are so many variables when setting up a car that you can not really be campairing apples with apples here. You tune your car to work and handle they way YOU want it to. We all drive differently so the car must be set up to reflect that. There is no right and wrong in that regarde. I think of the Senna Vs prost days. Same Mclaren. Completly deferent set up and driving styles. Fastest laps and poles buy both. Think about how you like to drive and then work backwards.

 

Oh and just to be a real pain in the but; the technical side of me says "Yeah 50/50 balance and drive it on the rails", but the fun side says" hang it out" and then the just about to lose ones licence side says " it a public road and if you are going fast enough to tell the difference you are going to burn sooner then later."

 

Will I ever learn?

[Mikelly]

Idaho Z,

Hmm, I take issue with calling Lone out like that. Lone only stated what makes sense to him and others here. He isn't claiming to be the authority on anything. He is also not looking for a fight here... He joined a thoughtfull discussion and thought he could add something... Your comments caused him to feel like HE couldn't add further to the discussion...Congratulations in making him feel the exact way that you voiced concern over Scarab members feeling....

Your conversion is a scarab...Others who have owned that conversion and switched have given their reasons for switching. You don't like the JTR Manual..If you have a copy, put it on the board here for sale...Others could use it... You have a Scarab conversion which is fine, no harm no foul..works for you..

 

On to JTR and Mike Knell, Lets remember that Mike Knell isn't a voice here on this board, and just like many others, I don't agree with everything written in his books.

 

Not unlike Mike Knell, I have written my own experiences down for others to use. Have they been "Expert opinions"? No. They have been what I thought made sense to me, and wanted to share with others. Based on this thread alone, I'm glad I scrapped the idea of writing a book on modifying the Z, as I'm sure I would have caught such critisism.

 

Mike Knell Wrote what he wrote and many here have put his examples to use. You take issue with that, and your concerns have been answered repeatedly. Not sure what else can be gained from this discusion. There is NOTHING to be gained by pitting the scarab guys against the JTR guys. As for making it an issue, I said MANY posts back that it all boiles down to preference and driving style. However, from an engineering standpoint alone, Lowering the center of mass and getting it to a 50/50 IS the proper way to setup a car P-E-R-I-O-D.

 

As someone else posted...Its YOUR car. Build it to suit YOUR needs.

 

This discussion has run its course guys... I think it is time we put this (3 page) thread to bed.

Mike Kelly

[pparaska]

Please, before anyone posts to this thread, go back and read the incredible amount of info that's in it. I think all the bases have been covered at least once, but I could be wrong.

 

Things are a bit tense in this thread. I HATE to lock any thread, but if no new INFO is being posted and we are just throwing spears back and forth, I will.

 

Please don't post to this thread unless you have something new to add. A story of why you went from a Scarab position to a JTR, a new technical insight.

 

I think we've beat this topic to death, but I do encourage new thoughts, ideas, testimony...

[Guest Anonymous]

This post is HUGE and extremely interesting!

 

After reading all the posts at least once, I have a question or two.

First, I was one who emailed Kim about questions regarding the Scarab type install because after working on my Z for a year doing body work, I want it done and on the street ASAP! For me that means installing the V8 with the least amount of issues, and the driveline angle and oil pan clearance issues both bother me.

 

With that said, what about the MSA kit? It seems like it may be a good comprise between the two. According to a post I read, it sits further back than the Scarab, but not as far as JTR. It is also available with a premade driveshaft, although somewhat expensive imo, it may not be much more if time and frustration are a concern to just have it delivered to my door.

 

My main question that I hope someone can answer is this. Does the MSA mount the engine as low as the JTR mounts? If the oil pan doesn't hang down as low as the JTR does I may just buy the MSA mounts at $195. and then have the option of using their driveshaft as well.

 

Btw.. Johns Cars is not the only place to get the Scarab conversion... Hooker still makes it and it can be purchased from Summit or PAW.

 

 

Thanks in advance,

Jerry

[Guest Anonymous]

Jerry

I put my MSA mounts in 3 months ago 280zx oil pan is 3/8 to 1/2 inch off the crossmember.I have mabe a 3/4 inch clearance between my MSD billet distributor and the fire wall. I would like to weigh the car for weight distribution. I'm losing the rear end in high speed hard cornering but that with stock tires.

[Guest Anonymous]

Howdy,

 

This otta get the ole time moderators attention.......

 

I just joined the board, don't know how long I'll stick around.

A few comments.

 

I'm the "young man" that Kim talks about who believes in the JTR conversion.

I still believe in it.

I've got a 9:1 chevy 350 with RV cam, turbo 350, q-jet, 2000 rpm stall converter. When brand new and fresh, I ran a 14.0 at 102 mph with the car.

The motor quits going faster when the tach says 5000 rpm.

It is an open diff r180, and I run 7 inch wheels all the way around (all that will fit in stock wheel wells).

Kim's car has been clocked in the 11's in the high 120's I believe. Correct me I'm wrong please.

He's got a few ponies on me.

At a hill climb, horsepower matters. So do fresh tires. Kim made his point that he can beat me.

And he did.

 

I do well at autocross where my torquey motor has an advantage. His car does better in the higher speed stuff - no argument. My car is better in the tight stuff.

 

I sat face to face with Kim where I thought he told me his opinions on keeping weight forward. Yup, I shouldn't have posted what I did (frankly, I don't remember it being that blunt - I do feel bad, and if I haven't apologises before, please consider my apology now).

 

When all done, I still believe that weight matters.

My priorities:

1 - Lose weight cheaply.

2 - check bank account, and spend more money to lose weight.

3 - move weight you have backwards in the car however you can cheaply.

4 - move weight you have backwards in the car however you can spending money.

 

Formula cars run mid motors. They run super low CG's. They run 55-65 percent rear weight. This isn't because they can't run motors in front, it is because they can't run motors in front and be competitive.

 

I don't know how good of a driver I am in an autocross. I think I'm pretty good, but probably not great. Running against nationally competitive SS cars 2-3 years ago, I was mid pack - perhaps 1 second back from first on a one minute course. Obviously SS cars have gotten lots faster, and my car is for sure slower.

My point? I'm agreeing that v8 z's can be quick. They can be somewhat fast, but that isn't what they are great at.

And I agree totally that they are the greatest bang for the buck out there for a street driven car.

 

Scarab is easier. JTR is more work, but you get weight back and down for the same price excluding your labor. The JTR book is worth its weight in gold though for providing part numbers, clearances, methods, and answers. As far as I know, there is no Scarab book out there.

-Doug Miller

71 240Z

~53 percent rear weight with me in it and 4 gallons of gas, iron heads, 4 gallon cell without rear stock tank.

[Guest Anonymous]

Are you guys HOT are What . My computer is smoking just scolling through. I kind of like the idea of a sbc setting lower and further back despite the extra work. Sounds like Republicans and Democrats on political theory. JTR All the Way in 2002.

[Mikelly]

Doug, Glad you could show up to the party. Kim and I obviously don't see eye to eye on this as he feels that I publicly humiliated him. I don't see it that way, and only since he left the board have I found out who he is in the Zcar community and his frustration over the JTR manual and Mike Knell.

 

My car has the JTR mount setup and yes it does require a bit more work, but in my opinion worth every penny if you are doing the install from scratch. I drove my Z on the street HARD for about a year, and never hit anything with the oilpan and once I did the mustach bar bushing tip outlined in the JTR manual, the driveline angle issue was resolved. In my opinion, and I'm no expert (but I've also not got an AX to grind with Mike Knell or Kim), it just makes sense to me if you can get the weight balanced and low, just like most racers set their cars up. If I had bought a Scarab setup car (And I didn't because of what I heard about their handling issues) I might not mess with it. But it really doesn't cost that much to convert a scarab car over to the JTR... Swap a starter, make a new driveshaft, and re-route or extend the exhaust, and drill some holes for the trans mount. To me, the added benefit would be worth it. Mind you, I only drove a couple of Scarabs that were poorly done examples... Jim Mcnemar's car is an EXCELLENT example of a well engineered Scarab that might prove my theory wrong. From what I hear about Kim's car, I'm sure he spared no expense either, which would make his car a potential contender as well.

 

Again, I believe that the two issues, the oilpan and driveline angle, are non-issues because there are active solutions out there. I also believe that making your own mounts would also be a wonderfull idea in the end... Weld them onto the framerails, after you beef up the frame rails...One thing I hate about the JTR mounts is the added (Yet minimal) vibration you pick up from the mounts. Still, there are endless ways to do the conversion using motor plates, and a host of other mounting solutions. Bottom line here is that there isn't always a "Right" answer, just options or opinions, and many believe the JTR is better, and some don't. It will ultimately be up to the individual. Mike Knell provides a TON of usefull data in the book. Just don't believe EVERYTHING you read in it...

 

Doug, Glad you found us, and I hope you stay. And if Kim is reading this, You are always welcome back to the frey. Water under the bridge to me.

 

Mike Kelly

ZF Racing LLC

[Guest Anonymous]

Wow!!! I have enjoyed reading this for the past three to four months. I have kept my opinions to myself but after my car has been mentioned I feel obliged to give my 2 cents. (Thanks Mike)

 

Everybody is right!!!!!! I have a 73 240z that was factory built in 1977 by Scarab. Mike Kelly has gone over this car from top to bottom and he has shared with me that the motor is further back and lower than any "Scarab" conversion he has seen. Since Scarab has been out of business since 1982 is it possible that current Scarab conversions are just a little bit different than the factory installation??? Maybe.

 

To our young friends that are contemplating conversions, regardless of your choice of Scarab "position" or JTR conversion you will be sitting in an extremely fast car, make sure you have invested in brake and suspension upgrades before you go fast safely or very bad things can happen in a flash.

 

My Scarab carries 500 dynamometer tested horsepower. This car is extremely quick and has never been beaten in the 16 years that I have owned it.I have a letter from the man that built this engine and he encourages me to engage my brain prior to engaging the drivetrain to prevent catastrophic results. He felt this necessary even though I am 46 years old.

 

Finally, I have met many men with very fast machines and some are capable of handling them and some are not, the proof is that some men can drive well and some need to improve.

 

JTR/Scarab, in most situations it will result in far more car than most people should have and if you are really good it probably will not matter because you are good.

 

Have fun, be safe and continue the argument because it is possible that the original factory installed Scarab is just as fast and almost as balanced as a JTR conversion.

 

I still believe that Mike Kelly could take my Scarab and beat his own JTR...He's just a very good racer and hates to loose. A very tough guy to go against.

[Mikelly]

Jim, I'll take you up on that...JUST TO GET TO DRIVE YOUR CAR!!!! LOL! Seriously, bottom line is these cars are quick no matter the setup... and it does boil down to preference, which means everything to the individual!

 

Good luck, be safe, and have fun guys!

Mike Kelly

ZF Racing LLC

[Guest Anonymous]

Mike, you are on but I get to drive yours. We will do this at Summit point this year after we do your suspension upgrades. It will be great.

[Mudge]

Originally posted by BLKMGK:

Things like 50lbs of weight moved around can really change how a car handles. That might only be 1% but it could be enough to change things. I know in the case of my RX7 that folks report they can tell the difference when a lighter BATTERY is installed - it sits way out front just past the front axle FWIW. Mine weighs a ton

 

P.S. Adding weight to the front of a car in order to keep it on the ground at speed just feels "wrong" to me.

Agreed. This is an issue most american car owners face (Camaros, etc). Moving the battery to the rear, etc all used by people who road race these poorly weight distro'd cars. I'd rather keep the front end tied down via aero.

 

Saying that more weight up front is best, is like saying that Ferrari's suck because of thier 40% front/60% rear weight distro which is often used by midengine cars.

 

I am not making a statement of JTR versus Scarab as I don't know enough of either yet.

[Mudge]

Originally posted by pparaska:

I'd also rather use front downforce to deal with high speed stability than to move the engine forward. I see no real useful advantage here for street speeds, so no advantage either way for me.

Yet again I have to agree, why make up for a bad driver with a poorly handling car? Having a heavy front end (again like in my 4th gen Camaro) results in poor turn in, loss of grip on the front, understeer city!

 

This is fine for most people getting to work, but on a road course (not a straight line venture) then this is definitely not optimal.

[Guest Anonymous]

Blue Oval

 

Where did you get that body kit?

[Guest Anonymous]

Bubafet..that aint no body kit.Blue Oval Z is our fiberglass expert as shown by his work .................................................................................................................................................................................... ................................................................................................................................let this infamous thread rest in peace