Hello to All

[Guest Anonymous]

Hey guys, I found this site a few weeks ago, and have been reading alot.

OK, heres what I'm planning.I've built a 400 small block,with a th350.This is going to be a drag only car. I wanted to use the rearend that came with it, I love IRS.This just a hobby type car, nothing too extreme, with a lil over 400 hp.I'll need to have a kinda high stall as well. Will the R200 hold up at all, with slicks? Or do I need to go straight to the 9"?

[Guest zfan]

Welcome! The v8 Z with approx. 400 hp with constant abuse mite be too much for the r200.

I would say if your building it to race at the strip but want to keep irs I would look at r230 from Nissan Q45. As a matter of fact I believe Davey may have one on Q45. Im sure he wouldnt mind you boorrowing the back end.

 

Just joking! 9 inch aint cheap!

good luck Mike

[DavyZ]

Thanks for suggesting it Mike....

 

Welcome to the forum! I agree with Mike (zfan) that an R200 might not take the shock from the slicks. Scottie, Rick, and Andrew drag race their cars all the time and each has an IRS. Their input would be helpful. I have even heard of guys (Scottie maybe?) that have stub axle hoops (like a driveshaft hoop).

 

David

[fl327]

hey davey, maybe this is crazy thought, but maybe you could swap rearends from the q45, to your future Z, and put an r200 in the q45????

i was having a little trouble with my diff, found that the solid diff mount and some new hardened driveshaft bolts cured it!!!

im running at most about 275hp and 300-25 tq

and once anything is slightly out of wack in the r200 area it gets shaky, combine that with slicks, holeshots, and lots of racing and i think its a recipe for disaster, even though the r200 is very strong. i would say, break it first, then swap it out. i think its fine for a daily car that can run high 13s-low 14's, anything greater than that, watch out!!!!

[DavyZ]

Hack up my Q45 for the sake of my Z?!? I don't think so! My R200 diff is just fine and I'll use it in the Z. LSD is not the end-all be-all of rear ends.

 

David

[BLKMGK]

Fairlady - Scottie is starting to push 10s with his R200. He has a transbrake and drag radials with some decent 60fts. He's not broken the ringpinion yet but I think he's done in a few stubs and halfshafts

 

The ring on the R200 is nearly as big as the one used in the 'Vettes so I'm not too worried about it's strength. The bigger issue is the halfshafts and whatnot including stubs that bolt to it. It's a strong rear but you need to have good stuff bolted onto it which is why CVs are so popular. When my Us break I'll worry more about it. I expect to hit low 12s at least and would like 11s. Heck the JTR book even mentions a nasty fast Z with an R200 in it.

 

So long as we've not got axle hop or fender wells hitting the tires on launch the R200 is apparently proving pretty durable. The R230 attraction isn't so much strength as it is availability in an LSD form with differentbetter ratios for some people. I won't swap mine out without very good reason...

 

[ June 13, 2001: Message edited by: BLKMGK ]

[Guest Fast Frog]

Welcome to the forum!

 

As most have said, the R200 rear end will stand up to a major amount of punishment, but you might consider other options if your ride is going to be a drag only car. I've got a 383 and had it supercharged for 5 yrs until last fall(sold the SC). I was pumping out 425+HP, but I didn't race but once and really don't abuse it. The whole rear end is still in good shape.

 

[ June 13, 2001: Message edited by: Fast Frog ]

[Scottie-GNZ]

Davo,

 

welcome. Boy, you sure know how to get to the bottom of a hot topic right off the bat

 

Being a 280ZXT, you already have all right pieces in the IRS except the LSD. If the car is primarily a drag car with little street driving, I say weld up the 3.54 and run with that. I am pushing about 500 lb/ft of torque at idle, OK maybe it is not THAT low , launch with a transbrake and use a relief valve to help get instant max boost off the line. Short of a monster BB, that is probably as much abuse as the IRS will get unless you have the wrong setup and get massive wheelspin and wheelhop. To date I have broken the driveshaft and a driver's side CV. The driveshaft had a rear OEM-sized u-joint so that was understandable. Experts say the pass CV is usually the one that breaks, so maybe my breakage was a fluke (I hope).

 

If I was doing your setup, I would make sure I got the correctly matched converter, add a t-brake, add a line-loc, weld up the 3.54, build a 3" driveshaft, tie down the nose of the diff (see my website), stay away from stiff shocks/springs, run 275/50-15 DRs. The BFGs are stickier but do not last very long. I love to spend other peoples money but what I listed is what is working for me.

 

I am seriously considering a solid rear so I can run slicks and put this puppy on its rear bumper . I also need a higher ratio to avoid having to shift in OD and choice of ratios just is not there for me with the IRS.

[Andrew Bayley]

I guess I'll chime in here.

Scottie and BLKMGK have hit the nail on the head here. From what your setup sounds like, an R200 will be just fine. Sure, I've wasted a few R200's in my time... but these were also the same rear end's I found in junk yards buried underneath three feet of mud. In fact, on of my now-dead R200's had 250,000 miles before it gave up the ghost.

 

The big thing to consider is the half shafts. The CV shafts in your ZXt will work better than the old U-joints, but I don't believe 100% that it's because they are stronger. The CV's are a lot more forgiving at "squat" angles than the u-joints. If the u-joints are setup where the squat angle is at a minimum, they should last. John C from North Eastern Canada runs mid 10's on slicks with an R200 and U-joint half shafts.

 

When building your setup, I would suggest looking into adjustable coilovers. This helps "fine - tune" your half shaft angles while still allowing for adjustable normal street driving. I run down the track with a pretty good rake, then lower the rear's down for city driving. I agree to be careful when thinking about a "stiff" suspension, but they can work out nicely. The big thing to remember is to get the car to sit quickly, and keep it there. A stock suspension will launch nicely with up to 300 hp, but more than that might require a little more spring in the back.

 

I would recommend against lowering the car for drag racing. In virtually every rear suspension design, lowering the rear suspension will ruin your launch. Basically, draw a side profile of your car and locate the center of gravity. Next, draw a horizontal line through the cg. Then, draw a line from the rear wheel contact point, through the cg, then out over the front wheel. Ideally, the best setup is to have the same distance "above" the cg horizontal line that there is between the rear wheel contact point and the horizontal cg line. In fact, sometimes more than 100% (equal spacing) is better for launch characteristics. Of course, ride is usually affected by this. This is why I went with the coil overs.

 

My final though is on the welded rear end. I am currently running an OPEN non-welded rear end. I've yet to have too many problems with wheel spin while running my drag radials (275/50/15... size of choice ). If I ever have problems in the future where I cannot hook up at all, then yes... I will weld my R200. But it has yet come down to that. I've driven a few welded cars on the street and I'm rather glad I haven't had to do this yet. Makes fitting into tight parking spaces a little easier.

 

Good Luck in your project

-Andy

 

P.S. Here's a picture of the halfshaft loop previously mentioned:

 

(No Picture? Click here instead!)

 

[ June 13, 2001: Message edited by: Andrew Bayley ]

[Guest Anonymous]

I want to thank everyone, for their time and knowledge.I'm going to run the R200 and see what happens. I'll keep you all updated and I'm sure I'll be asking more questions.