Guest Anonymous Posted July 12, 2000 Share Posted July 12, 2000 I was just wondering what the top speed is on some of the daily driven v8 z's? [This message has been edited by Head (edited July 12, 2000).] Quote Link to comment Share on other sites More sharing options...
Drax240z Posted July 12, 2000 Share Posted July 12, 2000 The sky is the limit really, but a few are shooting for the 200mph zone. I'd guess that most are geared to top out at about 160mph or so. ------------------ Drax240z 1973 240z - L28TURBO transplant on the way! http://members.xoom.com/r_lewis/datsun.html Quote Link to comment Share on other sites More sharing options...
DennisK Posted July 12, 2000 Share Posted July 12, 2000 If you go to "Links", then "Transmission/Rear en Ratio Design studio" you can plug in specs and see what Top end is in theory, on paper. However, reality is pretty much what Drax covered. Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted July 12, 2000 Share Posted July 12, 2000 Without proper aero considerations I've been told the Z begins to get airborn at around 160mph. Mike Kelly and I talked about this as he's got big MPH goals. If this is something you're looking to do - say 200mph - talk to Mike as he had some ideas for keeping it on the ground. Front spoiler a must, belly pans and other things possibly needed. Seems the Z makes a nice wing! Quote Link to comment Share on other sites More sharing options...
Guest Fast Frog Posted July 12, 2000 Share Posted July 12, 2000 Head: With my reply, I'm going to answer your question and also verify the replies of Drax and BLKMGK. When I bought my 76Z brand new, I eventially took it up top end on a back stretch of road nr Ft Collins, Colo. I got it up to 116-118mph-that's all it would do. At that spd the front end felt lite and "swishy". A couple of yrs later I turbocharged it and could get it up to 135+mph. This was scary. I was still running a stock Z with no additional areodynamics and the car was all over the road!! I added a front air dam and this cured most of the problem but it still bounced a lot. Later, I installed performance springs and Tokiko struts. A few yrs later, I upgraded my turbo to a mini-grand nat'l with 15-17lbs of boost and added a standard wing to the rear hatch. This kept things "glove smooth" to about 150 mph then I could feel it start drifting and shaking. Five yrs ago I went 383 ZV8 with a Paxton. I also redid the body and paint. I added side skirts and 10" rear whls with IMSA flares. It will now do 160-162mph (measured from the tach at 5800rpm with a 3.54 diff and .75 OD 5th gear), but at that spd it starts to drift and shake again!!! I discussed this with a tech writer for Turbo and Hi Tech mag who was into Bonneville Salt Flat top end stuff. He told me that the aero upgrades that I had done so far were good but until you eliminate some of the turbulance under the car, it's an iffy ride at any higher spd. He stated that at those spds, the car is literally riding on pockets of air and turbulance which make it shake and actually drift from side to side. Also, you're "drag coefficient" (front of the entire car aerodynamics) really starts to become a factor at spds of 150-160mph. And for most street setups, you're usually well past the power curve of most street cams (mine drops off at 54-5500rpm). So you hit a "wall" at 150-160 mph. It was the Paxton that kept my engine pumping to a higher rpm. I'm satisfied that the car, indeed, can do 160mph. But to do any more would probably require a total areo redesign not just bolting on more aftermarket things. [This message has been edited by Fast Frog (edited July 12, 2000).] Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted July 12, 2000 Share Posted July 12, 2000 Thanks for the replies. I'm hoping to start on my V8 conversion in a few weeks. I tried a while back but the steering box was in the way on my 1980 280ZX. I've been wanting to do the conversion for a few years now and it looks like its finally going to happen! I can't wait to play with some vettes and my friends' 3rd gen rx7s! Quote Link to comment Share on other sites More sharing options...
John Scott Posted July 13, 2000 Share Posted July 13, 2000 I've had mine way to fast for a short stint. 5800 in 4th .7 overdrive, 3.54 gears. Above 160+! Only for a few moments. Didn't take long and had plenty left.Scarey! I'm gaining a little more sense as I get older. I don't want to be a test pilot again unless I have a proven body/chassis system. Really good rubber is a must, too. It boils down to: Just because you can doesn't mean you should! JS [This message has been edited by John Scott (edited July 12, 2000).] Quote Link to comment Share on other sites More sharing options...
Guest Jason Posted July 13, 2000 Share Posted July 13, 2000 I was looking around the camaro site http://www.camaroz28.com/ (trying to find a T56) and noticed they had an aerodynamic and rolling horsepower calculation page. Its listed under "Automotive Calculations" in "What's New!". You'll also need the transmission studio page to know what your RPM's will be so you can guess your HP at the speed you pick. If you have any earlier performance figures for your car (top speed and HP at the RPM's you were taching at) you can use that knowledge to tweak the input values for more accuracy. I think a stock Z has .468 for CD and under 20 sq feet of frontal area. Head, I have a 1982 ZX with power assist rack and pinion, and plan on an engine swap. Is this what you had in your ZX? Did you figure a way around the steering or buy an earlier Z? -Jason Quote Link to comment Share on other sites More sharing options...
Guest Frank280z Posted July 13, 2000 Share Posted July 13, 2000 Not road worthy yet. But four speed. 3.55:1 rear. I'm guessing 135-140?? I'm more concerned playing cat and mouse around town with the "big mustangboys". HeHe!!! Frank ------------------ Build it. Drive it. Improve it. Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted July 13, 2000 Share Posted July 13, 2000 I ONCE top ended my Mustang when it was mostly stock. Speedo only went to 85mph but those cars were good fro about 135 from the factory and I was probably closer to 125-130 at the time. A 928 was side by side with me and at that speed DOWNSHIFTED and left me sitting still! Then came the "interesting" part. Slower traffic ahead! Try this sometime while riding with someone on the highway. Look out the window at the stationary objects along the road coming at you. At 60mph those objects are coming at you at about the speed they would if you were doing 120mph and they were doing 60mph. Scary huh? I quickly learned that the brakes on an '88 Mustang were pretty crappy! First upgrade to that car was brakes, then wheels to better vent them. I've since gone to even bigger brakes and beter wheels I still have the 85mph speedo in hopes I won't be tempted again and I never intend to do that again on a public street. I have no idea what it's top speed is now or was after I doubled the horsepower and that's fine by me P.S. No, I didn't hit another car but I sure scared myself the way those tailights got real BIG in a hurry! Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted July 14, 2000 Share Posted July 14, 2000 We had my friend's 3000gt VR-4 up close to 150 MPH a few times. It really gets your adrenaline going! Jason, We haven't started on my 280zx v8 conversion yet. We attempted to awhile back, but the "steering gear" box got in the way. My dad is planning to remove the box all together and replace it with the rack and pinion system from a pinto that we're also doing a v8 conversion on... Supposedly MSA has the proper engine mounts for the 280zx with the steering gear box. I wasn't going to get them a few days ago, but now I think I'm going to break down and buy them. I was reading in the v8z special in ZCarMag that the MSA kit is close but it fits around the power steering of the earlier 280zx's. [This message has been edited by Head (edited July 15, 2000).] Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted July 22, 2000 Share Posted July 22, 2000 My 280ZXV8 has the non power rack'n'pinion, and all clears the steering OK. Drivers side header (cheap hedman, going with a set of 1-3/4's rewarder headers shortly) had to be bent outwards a couple inches AIR to clear the steering shaft and my oilpan is quite tight to the rack/crossmember but I can't see an easy way around this to gain hood clearance and keep the car's weight low. I did just have my oilpan notched out for my last build but yet to drop the motor lower as I need to redesign my motor mounts for this. Quote Link to comment Share on other sites More sharing options...
Mikelly Posted July 25, 2000 Share Posted July 25, 2000 A couple of things I'm investigating are Belly pans and a chin splitter. Also going with coil overs up front allows you to create the wedge effect. That helps emensly. I'll be testing this out next year at Nevada hopefully! I've had several Zs up in the 150-160mph range and even with suspension mods they tend to get a little loose at top end. They also started to vibrate a bit, due to the inline 6 vibration issues... I tore up several crank pulleys over the years... Anyway, the coil overs and chin splitter will help a bunch and the belly pans will do a bunch to clean up the air under the car. Now, beware of belly pans... Without a wind tunnel, there is no guarantee that the air you are smoothing out isn't still creating problems elsewhere under the car... Think of that undercar air as mini tornados causing bunches of barametric pressure building and eventually causing your car to take flight! I'll hope to avoid that for 93 miles from Hyko to Lund... I've done it once in a rental car... the route was a hand full! Mike ------------------ "I will not be a spectator in the sport of life!" mjk Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 17, 2000 Share Posted November 17, 2000 quote: Originally posted by Head: Thanks for the replies. I'm hoping to start on my V8 conversion in a few weeks. I tried a while back but the steering box was in the way on my 1980 280ZX. I've been wanting to do the conversion for a few years now and it looks like its finally going to happen! I can't wait to play with some vettes and my friends' 3rd gen rx7s! It's all good and all, but 3rd gen RX-7s have their place. If they were built for acceleration, they would run 7 second 1/4s (which they do) but your friend's (which I think I know who) are primarily built for cornering L8R head Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted November 23, 2000 Share Posted November 23, 2000 Just picked up a 3rd Gen RX7 myself - strangly enough I also just finally got my Z out of paint shop jail The RX7 is just plain nasty, even with a wounded turbo on the primary side that won't go past 6lbs of boost. When the second one kicks in at a full 10lbs it feels liek a truck just hit me and the motor makes all sorts of neato' whirring sounds! Make no mistake - these puppies haul the groceries. I expect the V8 Z to be faster in the end but I don't think it'll take the RX7 top end. At 80mph the RX is just starting to feel good in 5th and it feels like you're only going 55mph. Step into the gas and it takes off at 80mph and pulls hard till you let off. I've not done any real high speed runs but have chatted with folks who have seen close to 180 in modded RX7s - that's scary fast IMO. My Z will weight a bit less than the RX I hope but the RXs only weigh about 2800lbs supposedly and making 350+HP isn't too hard or beyond th erealm of bolt-ons. I hope to hit that number myself and 425+ with the Z. We'll see! Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 23, 2000 Share Posted November 23, 2000 Hey, Sorry, but I have to do this. I have owned 3 3rd gen RX-7s. All of them being R1s. Recently, a lady decided I didn't need to own my CYM (only 250 made) RX-7 anymore and tapped me which made me spin into a wall. Well the car is totalled, which made me look toward V8Zs. Anyway, the RX-7 is the car I first started driving and working on. I love every aspect of them, from the braking (60-0 in 113ft) to the acceleration (0-60 in 4.9 seconds). The potential is huge in the RX-7. One of my good friends owns the fastest stock turbo RX-7 in the world. It runs 392.5hp to the ground and weighs 2750 with driver. I will always love the RX-7 and there are some parts of it's character that can never be replaced!!!! I hope to find the sheer drag race jump that the RX never offered, in the V8Z. BLKMGK, take GOOD care of that RX, and if you ever need advise or even parts, I have plenty! May the RX and Z come back to the US once again!! Sorry, I promise that's my last RX-7 post. ------------------ Will always be a rotorhead on track, but my V8Z will dust you on the street. Quote Link to comment Share on other sites More sharing options...
pparaska Posted November 23, 2000 Share Posted November 23, 2000 I personally have no problem with you guys talking about the RX's here. I agree the basic formula is the same as the HybridZ - light car, lots of power, great handling and braking potential (with available parts for the Z). If I had more money and room, I'd love to have an RX-7! Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted November 24, 2000 Share Posted November 24, 2000 Well, since we've brought it up... check out this car -> http://www.rrow.org/rrowmembers/3rdGen/LaBreck/jim_labrecks_rx7.htm and then check this one out, it's the same car -> http://members.tripod.com/~grannys/3rdgenrx7chevyv8.html Sound familier? Someone posted a link to this car bemoaning what he was doing. I pointed him this way since I figure we're closer to kin than they are and are using much the same hardware. Of real interest is his use of the stock ECU for the LT1 and the use of LT1-Edit software. I wonder if that ECU could be used on our cars or if it would even make sense? Anyway, I'm having fun with mine and appreciate the offer for help - got a passenger side door pull in black? Coworker of mine broke it about 2days after I bought the car (sob). This sucker hits 60mph in second gear - scary fast. I can hardly wait to get the Z running to see how it runs too I'll post some pics of both as soon as I get off my butt and get the server up here. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 24, 2000 Share Posted November 24, 2000 As a matter of fact BLKMGK, I run a local parts company. We deal a lot of 3rd gen RX-7 parts. If you need stock or aftermarket, I can get you an amazing price! Wholesale distributor anyway, about the V8 RX-7... This is the one thing I do not like about certain RX owners, granted it would make for a hell of a drag car, it's not practical for anything else. For the Z, the V8 is great, it needs the hp, and it actually improves handling by weight distribution (with the right mounts ) However, I feel the rotary belongs in all RXs (since that's what RX means). The rotary engine is an amazing work of art, it's 1.3 liters of pure power! A 3 rotor engine with a twin turbo unit from the third gen RX-7 will pump out 541 hp stock, when you add injetors, intercoolers, upgraded turbos, etc, you look at the 700 hp mark. The fastest RX-7 is ~1000hp. it runs the 1/4 in 7 seconds. In fact, some submarines run on rotaries (8 rotors) and Le Mans cars have run on 4-rotor engines in the past, what a sound!!! Anyway, my point is that I don't feel the RX-7, from '78-'00, should ever see a different engine besides a different rotary. It may be the rotary pride talking here, the RX-7 has it's whole charater and existance built around the rotary engine. I say, keep the V8s out of RXs and put them in Zs Just my two cents. ------------------ Will always be a rotorhead on track, but my V8Z will dust you on the street. Quote Link to comment Share on other sites More sharing options...
Oltmann Posted November 24, 2000 Share Posted November 24, 2000 quote: Originally posted by V8 VPR: The rotary engine is an amazing work of art, it's 1.3 liters of pure power! A 3 rotor engine with a twin turbo unit from the third gen RX-7 will pump out 541 hp stock, when you add injetors, intercoolers, upgraded turbos, etc, you look at the 700 hp mark. The fastest RX-7 is ~1000hp. it runs the 1/4 in 7 seconds. In fact, some submarines run on rotaries (8 rotors) and Le Mans cars have run on 4-rotor engines in the past, what a sound!!! I agree, but from reading that first page my impression was that he had gone through at least three Mazda engines already. I'd call that a good college try. Obviously what he's trying to do is build his own ultimate car, just like everyone on hybridz. Despite their cachet, the rotories didn't deliver. Quote Link to comment Share on other sites More sharing options...
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