Getting upset with 240Z

[Guest Anonymous]

Alright; Let's see what you guy's really got! I have '70 240Z and doing BBC. This is a maximum effort street rod conversion with projected 750bhp. I must have a frame that will take it but I don't want no stinking "Roll Cage" running across my doorways! Who has info on a sure fix for this and/or experience (and good results) fabricating a full frame of box steel?

 

And Grumpy; What is this about two pieces of 3" alum. channel for a torque tube like the the old fords had. Is this practical to fabricate at home? I can't quite visualize it. What about the ball socket and 4 bolt flange they had so it would work? I read nothing about that. And might the torque simply tear the tranny loose and/or whatever?.....Cheezzz!

[rags]

Spiirit,

I put 2x3 box tube inside the rocker boxes on my V8 car and Have had good success. This was done about 15 years ago. When I had the bodywork done they added about 3/8 inch of plactic to the roof to get the hatch to line up correctly (don't ask) and to this day you cannot tell. From memory I can tell you that the 2x3 is tied into the rear foll bar which is attached to the roof on either side of the dome light. I also made a box on the floor behind the seats that raised the floor 3 inches. I welded a piece of 1x1 from the 2x3 in the rocker box up to the rolll bar, then welded a piece of 2x3 from the 1x1 along the floor to the trans tunnel. I then put a dummy floor on the top of that piece to the vertical piece that goues up to the hatch floor. Does this make any sense? We'll anyway I'm only using a 327 but it is a stick car and I do NOT baby it!

 

Joe

[Guest Anonymous]

Joe; Thanks for the reply. Seems that NJ is another hot bed of car enthusiasts as I keep seeing the state come up online all the time and for everything.

 

Well, I don't see everybody jumping up and down on this one. But I did just find a website that has about what I need to do framewise. Heh, they cut the entire body loose from whatever is under there, removed the entire floor and used the 2.2x4 inch box for the main frame and then used side butts of same to the body in three places both sides. Since "Uni-Body" twist is the concern, I suppose this action will prevent that for the most part with maby a modified roll cage that suits my specs. I just don't want to see and to have to hunch over that bar across the doorway. I will likely put sumething level with the butt cushion itself and no higher.

 

I guess that's it! Goggles, mask, torches and a good ol' Sawsall should get me started and keep me happy for a while. Man, I sure never thought it would get this deep; Fabricating the whole damn frame? ..... fooey! But the "Ride", ahhh, the ride will be magnificent! Tell me this is true .....LOL.

[rags]

The red one is the V8 car.

http://www.hybridz.org/phpBB2/album_pic.php?pic_id=70

Wouldn't trade it for the world!

[pparaska]

SPIIRIT, I'm not going to say that going without a full cage is the way to go, but I'd consider doing a cage like "Mark" from NC did. It hides behind the A and C pillars and is a full cage without door bars that get in the way. I wish I'd done that.

 

I did front frame rail replacements (2.5x2.5" .093 wall steel tubing) in the engine compartment HEAVILY gussseted to 2x3" .085 wall steel tubing subframe connectors. Here's the page documenting it a bit:

http://mywebpages.comcast.net/pparaska/structuralmods.htm

 

I also had a modified S&W roll bar installed. It connects to the front/top of the rear strut towers and to the top/side of the driveshaft tunnel.

 

Other than that all I did was replace the structural steel that had rusted, usually with thicker material. Like the inner rocker panel ends, floors.

 

I had an longtime ITS 240Z driver (Wayne Burstein) take a ride with me and I was hammering the car and throwing it through corners. He commented (without me asking) about how stiff the chassis felt. That was enough to tell me I'd made some improvement over a stock chassis.

 

Anyway, I think for a street rod type of machine with all the power you are planning to put in it, I'd look into a good tight-to-the-car full cage. They can be pretty unobtrusive, if done right. And they offer alot of stiffness, especially if they tie into the front frame and strut towers well.

[Guest Anonymous]

Pete;

 

Thanks for the URL, it has a great deal to do with what I am up against except for the rust which I managed to escape.

 

As for your suggestions; I am taking them seriously I have been trying my best to visualize how such excessive horsepower would move through the chassis so as to wrinkle/twist the body; I really haven't been able to do that. However, if the unibody section has nothing but the sheet metal it is made from as it's strength.....then I could see it happening under heavy accellerating pounding coming out of the hole time after time. If that would be the case , then it would seem to me that a 2x3 0r 2x4 subframe plus the tubular items you mentioned would give a safe margin of strength. At this point I am ready to go with that. Does this sound acceptable to you?

[pparaska]

One thing to consider is that the Z unibody is "flexible" in the front between the strut towers and firewall area. Large torque applied to the engine frame rails, resisting the reaction from the diff through the unibody will tend to flex this area a good bit. I think that the increase in safety and consistency in launch, etc. would be worth considering a full cage for a high torque application.

 

Although the frame rails and subframe connectors help to add stiffness and strength, it'd be more effective to add these attributes with a cage that goes through the firewall. Frames that try to add torsional stiffness in a flat (plane) are inefficient and less effective, compared to adding stiffness with a space frame structure like a cage.

 

I still feel like my car's setup (better engine frame rails tied tightly to subframe connectors, and installation of a meager, inefficient roll bar) is not the best course of action. That roll bar probably isn't doing much except help react SOME of the suspension loads through the towers. A correctly done cage like 'Mark' had a Circle track builder install in his car is a far better way to add stiffness and strength.

[grumpyvette]

get the roll cage correctly installed, it could save your life!

next think about this, the car will easily run 10,0@138mph if its set up correctly, if you blew a tire or snapped an axle at 138mph and rolled the car how would the stiffer floor help? most tracks REQUIRE a roll cage on cars that E.T. quicker than 11.0 in the quarter mile. if the door bar is your problem, they make snap out swing bars for door bars(to make getting in and out easy)

BTW having built and driven a 454 (Z) I can tell you that theres NOT A CHANCE IN THE WORLD YOULL KEEP THE BODY FROM FLEXING durring SHIFTS WITH 750HP if YOUR GETTING TRACTION WITHOUT A FULL ROLL CAGE!!!!!

[Guest Anonymous]

Pete;

 

Having an open mind coupled with being a "LIBRA" (vassillation), I always have a good time with myself making up my mind. Being a '50's Model A/Big Bore Stroker Flathead "street jock" and a clay track small time stock car driver for two seasons in my 20's, I have been away from the scene for all these years. Now I am taking a last shot and have to play "catchup" with a tremendous amount of data and also grab the experience of current persons like yourself and Grumpy. To me, I am just building a Toy, but I always build the "Max".

 

I loved to take on motorcycles in those days because of the maximum challenge it gave. I feel the same way now but I realize that I have no idea just how much reaction I will be getting from the Fuel Injected Big Block power currently available. Ya', I have the MT 29x18.50 Wrinkle Wall's so the bite will be maximum and therefore the "Twist" will be maximum also so, I am listening intently to you and Grump.

 

Alright then, I will have the "Roll Cage" done by a contact I already know and work it out with him. I just wanted to make sure I wasn't jumping on any youthful bandwagon and overdoing this item. So, it appears I will have a qualified "Drag Strip" car to use on the street.....LOL.

 

Much thanks for helping me make up my mind with this. (Camshaft will be next but much later).

[Guest Anonymous]

Pete,

Thanks for the compliments. I think I have some pics of my cage somewhere. Spirit, if you would like to see them, let me know and I'll post a few. Mark

[Guest Your Car is Slow]

Are we saying that a properly installed frame will curb the need for varioius other frame stiffening parts (SFCs, swaybars, strut tower braces) etc...or are you saying that it should be installed to complement those instead?

 

I can see doing one or the other (where the cage being the obvious choice) but doing all would seem a bit overkill IMO.

 

Then again ive never dealt with a vehicle as small as the 240

[grumpyvette]

with a correctly installed full end to end roll cage includeing suspension brackets ETC, you will not need other tower braces (they will be there already) and most of the suspension connection points will be also dirrectly on the roll cage

 

http://www.swracecars.com/rolbarlist.html#anchor1158811

 

http://www.upgrademotoring.com/safety/autopower_app.htm

 

http://www.cscracing.com/ck.htm

[Guest Anonymous]

Dear Grumpy;

 

The thing had better break 10 on preimum pump gas or I am selling it to you!.....LOL,

 

Ok, I am going with the full cage and likely the swing outs also (I will consult with and have a local installer to do that part).

 

Why you want to scare me with blowouts and barrel rolls? It brings back some oval track memories. But you are right of course. Never heard of blowouts with tubeless tires. What you say? Fronts MT 26x7.50 tubeless, rears MT 29x8.50 tubetype Wrinkle Wall. I got em' now. I am figuring 35psi. front and 12-25psi. rear. Safe to play with the rears like that? Car: 28-2900lbs. with driver.

 

The following is just so you can "Minds Eye" the situation concerning further statements and not to be brag/dreaming.

 

I have roughed out the engine spec's and so forth: Around 632cui @ 1.2hp/cui. Bore/stroke max. The only outrageous thing will be the aluminum rods, quench adjustment and all that. I only expect a 5-10k life here and even that would take me several years to aquire the way I will use the car. I am getting the best I know for all critical areas of the engine. The driving force in my thinking is max. cui. coupled with max. accelleration, so light crank/4.750 stroke is in there if I can get it, along with the longer good rods, quench for the rods, dished Eutectic pistons/pressed pins/plama moly rings, Trickflow 18 deg. heads (this is sort of up in the air now as I originally was going SBC, but the HP on the Dyno Program I was using showed a trmendous increase with these heads using the same CR. I intend to look into it again). CR/10.5 (thus the dished Eutectic's) on pump gas. EFI/Lingenfelter (His "Low Profile less expensive 4 barrel looks good to me as upper mid/upper range is where I want the torque band to appear ), 1.76 powerglide I know zilch about "Stall Speed" or even sure if it is of any concern with a powerglide?), Driveshaft: alum. or carbon. Rearend: 4 bar/9"/3.08 ford, 165mph top street speed. , tires you know. So what have I got here and what have I missed basically?

 

You will notice I left out the heart (Camshaft) because It is so complicated to me. Opinions say build engine around cam while others say build engine first then select cam to compliment that. I beleive you might well build around a cam you designed from experience but of course I can't do that presently and prob. never will. But I do know that with the CR I want I must know what is right camwise for it to work (I expect it to drop to 9.5:1 overall). What is your recommendation as to how I should approach this area?

 

I WANT A "CHANCE IN THE WORLD" CAKE AND EAT IT TOO CAR!

 

Sincerely,

 

Tom.

[pparaska]

I'm waiting on the edge of my seat for Grumpyvette's response to this one! This is going to be VERY educational, I have a feeling!

 

632ci! I couldn't stop smiling!

 

Talk about a BEAST!

[Guest Anonymous]

Lay everything you got on me. I am sponge

 

Thanx.

[Guest Anonymous]

My suddeny very good friend Grumpy;

 

Dayyyummm Grumpy, you got an angel on your shoulder! I can weld good. Bolt in's? My My! Prices good too. Like it or not we are friends!

 

Just proves that "Keyword" rule!

[Guest Anonymous]

Well Pete;

 

I hope I am not just making a fool of myself but all I got is what I can glean from online and a few books I have sent for (just for medicinal purposes you understand).

 

When Grumpy mentioned his exploits I just knew he was my man.....so I laid it on him. I hope I didn't overdo it. It is a bunch. .....LOL

 

But guys like him seem to have a bottomless pit of info. I have had some friends like that in the long past.

[grumpyvette]

(1) 18 degree trickflow heads?

(if I read that correctly your thinking of putting sbc heads on a bbc block?)

OR ARE YOU TALKING ABOUT THE BIG DUKE HEADS

http://sonnysracingengines.com/flyers/BIGDUKEINDUCTIONKIT.htm

 

heres what your talking about and its too expensive and not necessary

 

http://sonnysracingengines.com/flyers/632CUINBIGDUKE.htm

 

heres a much more realistic engine

 

http://sonnysracingengines.com/flyers/PROBRACKET%20555CUINCHEVY.htm

 

but these are even cheaper and will still get you 800hp

 

http://www.theengineshop.com/engine6.shtml

 

and are a good deal for what you get

but heres what Id do BECAUSE I HATE WASTEING MONEY[/b]

 

Id get a merlin block, kit like this

http://www.theengineshop.com/sbkits7.shtml

 

add AFR 357cc heads

http://www.airflowresearch.com

a good 500hp nitrous kit

and a crane "

http://dab7.cranecams.com/SpecCard/DisplayCatalogCard.asp?PN=138781++&B1=Display+Card

and a good edelbrock super vic intake

 

with a 1150cfm holley

that puts you well over 1000 hp for about $14,000

[Guest Anonymous]

Grumpy, you sure you not related to Smokey somehow or John Adams with Mercedes Benz out of Dallas Texas? (A retired friend of mine).

 

You don't wear denim strapped overalls and keep sucking on a wheatstraw when you're at the track do you? (A sure sign of crafty engine genius).

 

Poo No! Although almost exact, I wasn't aware of any "Big Duke". I ain't paying no 25M for someone elses crate engine...LOL. Nor 10M for that matter. 6-7M and build it myself (except for milling, lathe, head flow and Dyno work etc.). If I am shooting too high it's probably because prices went up while we been talking. I may have to treat this like I do my heart pills, "Cut em' in half".

 

As to the heads, I built the SBC on paper with the Trickflow but switched to BBC without the research. If things are crazy costwise with the BBC game then I will drop back to the SBC but I would sure like to have those BB cubes as a solid foundation. I figured "What the heck. For a few dollars more.....", not pthhhhhhhtt... what you showed. I bet Pete is ROFLHAO as we speak!

 

Ok then, what do you recommend for BBC heads that leans twoard best choice for around 2M in this scenario and we'll let it go at that?

 

Your good friend,

 

Tom.

[Guest Anonymous]

Sorry, I didn't scroll down and get the rest of the story. By now I am beginning to suspect that the cubes I was seeing online were Merlin etc. bored all the way. How was I to know? They didn't say!

 

Anyway, I could do that but I want no more than around 750 and I am sticking with normal aspiration. (I don't want the hassle). I don't feel chargers or nitrous are into my game/class. It's like cheating to me, twin turbo's incluided (But on the street I will spank em' in the 1/4 and likely in the 1/2 if tuned right I think), but that's what makes it interesting huh?