JMortensen

I'm not the expert (see all my threads with questions about my own cage) but the guy who did my cage seemed to think that the diagonal was better at preventing distortion of the main hoop than an X to the rear strut towers. I didn't ask him about ANY combination of braces, just about the X as that was the other "usual" thing that I had seen.

I talked to the guy who bent my main hoop about all of this. He mostly does rally cages. His opinion was that you weren't going to do better than a diagonal that attached to the main hoop on both ends. SCCA rules call for a diagonal in the main hoop that attaches to the floor or as close to the floor as possible, but it was this guy's contention that having the diagonal attach to the hoop was a lot stronger than the floor right next to the bottom of the hoop. I think the point for him was that any distortion of the top of the main hoop has to bend the diagonal as well, where if the diagonal attaches to the floor it still props up the hoop but isn't as integrally attached and one can bend without affecting the other (as much). As far as the X in the back goes, it also props up the main hoop but does so from an angle and so it is weaker, which is why you need an X instead of just one piece for equivalent strength. Probably the best strength-wise would be an X in the main hoop instead of just one diagonal. The problem with that idea is that there won't be enough room for the driver's seat unless your under 5'6" or so.

I don't think there is a sanctioning body that would allow that, even if it was as strong. If you don't care about rules, then yeah, you might have a point. Would take some testing to see what works best.

I would just put a diagonal in the main hoop. That's what the SCCA rules call for these days, and it's less weight up high.

I should have asked before. Did you search? This subject has been covered A LOT.

I'm using an American Cams regrind. It is an honest .490 lift and 280 duration. It is too small.

When you link to a previous search it only works for a couple hours. Search the terms and you'll find 7 or 8 good threads.

That's what I hate about getting weights from the internet. I think your weight looks more realistic, so I think I'll believe that one until someone shows me different...

From: http://www.team.net/sol/tech/engine.html Ford 2.3 turbo weight = 450 lbs Ford 5.0 = 460 (late 5.0s are a bit lighter)

http://racerwalsh.zoovy.com/ http://www.esslingeracing.com/ I was looking at this yesterday and you can get a complete stroker shortblock with long rods and forged pistons for ~$1600 through Racer Walsh. Heads through them are ~$1000. So for $2600 you can have a professionally built long block from them. I don't know about Esslinger. They have a lot of stuff on their site but don't give prices for complete engines or heads, but they have a good name in the circle track world...

I figure that the stockers were just spot welded, so I didn't get too obsessed with sealing the seam. Speaking of which, if I were to seal the seam, I would use seam sealer instead of welding the whole thing. Besides, mine aren't sealed up against the floor in back either... I don't think you really hurt anything, but I think stitching is theoretically stiffer than seam welding.

Look what happens when you search "sprung unsprung puck": http://forums.hybridz.org/search.php?searchid=773554

That's the thing, this is one of the most popular circle track engines for the 4 banger class, so you can get a motor built CHEAP. Then you just get a big ol turbo and crank the boost, and all you really need to worry about is the engine management. Last time I checke the circle track guys have these things pushing 280 hp NA out of a Holley 390.

I should also mention that I think it's probably easier to get 500 hp out of the 4 banger than it is out of the V8, ironically...

You may want to check the weight on that motor. I've heard but haven't verified that it is almost as heavy as a 5.0. Also check your weight distro before you do the swap. When I scaled my car which had an L28, 5 speed, and R200 and an Autopower roll bar it was 49.5/50.5. The Z is REALLY close to 50/50 right out of the box.

I don't know. It seems more likely to be a connection thing, but ??? PM SuperDan and see if he has any ideas for you.

Check ebay. You can usually find those parts for about 1/2 that price. The other thing that you definitely need if they haven't already been done is replacement bushings. It's a chore to do them, so beware, but if you want to go for it then I'd suggest you call Summit Racing. They don't advertise their import parts, but they're an Energy Suspension dealer and can get you a complete bushing kit cheaper than just about anyone else. Summit also carries Suspension Techniques sway bars, which is also probably going to be on your to do list.

Find an L28ET engine/trans/harness for $500. It bolts right in and will fill your hp/torque requirements right out of the box, then you'll have money for all the other crap that needs doing like suspension/brakes/etc. After you get done with all that you might still have the cash to add an intercooler and some other go fast goodies. Lots of guys making 300+ whp on junkyard L28ETs. Read the FAQs on L28ETs to see what you can do cheaply and easily.

I drove that 510 with the welded diff and it was just like I described. You'd lift, turn, then the ass end would come around and you'd stomp the gas and go around the turn sideways. If you just turned into a corner without really abruptly lifting the throttle virtually nothing happened. It was very drifty but wasn't fast. If you got yours to turn in that's great John, but I still wouldn't recommend a welded diff for autox. Seen a lot of guys who use them for road racing, but the turns aren't as tight and I don't think the understeer issue is as bad at high speeds.

If you have 50 in/lb springs in front for a total front spring rate of 100 in/lbs, and a weight of 500 lbs on the front axle, the front end would sag 5". Now if you had one hundred percent weight transfer to the rear, then the front end would come up 5" on acceleration. If you changed the spring rate so that the front was 500 in/lbs combined, then the sag in front would total 1". With the same 100% weight transfer the front end would climb 1". So yes increasing the spring rate would keep the nose down.

Looks pretty kick ass to me!

Quaife is not a good LSD for drifting as it needs traction to work. Welded will probably work great. Just drop the throttle, turn in, then punch it. Should rotate right around. The car won't want to turn in at autox with a welded diff, that's for sure. I have a friend who tried open, LSD, Detroit Locker (R190) and welded. He ended up using the LSD.

You're right, I know that at least bjhines and I do differ with John on this subject. It's not completely unheard of for someone to differ with John, even if he is right 99.9999999999999999% of the time. My reasoning is that I can flex the firewall with my hand and I can flex the top of the cowl with my hand (visibly flexing), and as BJ said on another thread, my strut braces to the firewall didn't seem to tighten very well. On my old setup I actually cracked the seam sealer when I was tightening them down, so they moved A LOT. Now mine weren't centered the way John's and BJ's were and didn't straddle the 3 piece of the cowl's triangular structure the same way , but BJ's experience seems really similar to my own. He described the reinforcing that he did to the firewall to make it more sturdy in this thread here: http://forums.hybridz.org/showthread.php?t=118871. That is also a restatement of an earlier thread he posted when he originally came up with the firewall reinforcements here: http://forums.hybridz.org/showthread.php?t=109864. Also my 70 (build date 5/70) does not have that brace the BJ mentioned on the passenger side of the cowl. The driver side does have it, passenger side does not.

I just found a link to a site which has good info on bending stiffness of tubes, this is a good reference. Also his page on gussets is really good too. Not so sure I like his bender, but that's another story: http://www.thefont.pwp.blueyonder.co.uk/bikes/tube_size.htm

We've been over this one before, but I think that the Z strut towers flex OUT under cornering loads and IN under suspension loads like going over bumps in the road. I had a link to a BMW site that showed how this worked, but I can't find it anymore. Anyway I read this a long time ago in a Porsche Club magazine. They had put tattle tale dial indicators on the strut towers and measured deflection before and after the strut tower bar install, and that's what they found.