Driving Impressions?

[Guest Joek]

Hello All, I'm new here, but have reading lots over the past few weeks. I've been trying to find a new project and I'm thinking an LS1Zcar might be it.

 

I thought I'd ask those who have completed cars for some driving impressions and general impressions on the finished product. Like how does the car handle with a lower center of gravity and more weight towards the center of the car. How does it feel at normal highway speeds, as well as higher than normal speeds, hehe. What about around town driving. Noise, road vibrations, reliability. Gearing, does the 6spd feel like too many gears, or some that you maybe just bypass sometimes? Anybody do a 6spd and wish they did the auto, or vice versa? What about mpg, a valid concern with todays gas prices. I realize most of these things will depend on the specific setup of each individual cars gearing, exhaust, right foot weight, suspensions mods, etc and ofcourse personal preference, but I'd like to hear your varied opinions as well.

 

Thanks in advance, Joe

[73DatsunZ]

I know that the MPG varies between a 4L60E, and a T-56 and the way the driver drives is, but my 4L60E GTO (ls1) got 17-25 city (and thats babying the gas pedal), and I don't remember the highway MPGs.

 

If you prefer a stick, get the 6 speed, you will most likely be happier with it and I personally haven't hear complaints about having too many gears.

 

I am building an LS1 Z car, but I am not that far into my project, I am using the automatic transmission, I want to go the T-56 route, but I don't want to add ~$1,500-$1,700 to my build cost. Hope I helped you out some!

[maichor]

I love the gearing of my T-56 LS1. I have 3.7 rear gears though, probably different than yours. I would also say it depends on your use. If it is a daily driver, traffic car, or drag car, I say go auto. If it is a road course, auto-X, or hot rod, got T-56. I love to row gears and put the RPM's where I want. You can look up my first drive impressions at the link below, but my car does not run anything stock in the rear and I run a much larger tire. It might not be as useful to you.

 

http://forums.hybridz.org/showthread.php?t=96038&highlight=alive

[strotter]

'72 240, 350/T56, StealthRam, vortec l31 heads ported/polished, CompCams 283, non-adjustable Tokikos, real stiff springs of unremembered rate, 4 x 205-55-15's on 7" wheels, so on.

 

... how does the car handle with a lower center of gravity and more weight towards the center of the car.

This is one of those things that depends on suspension, tires/wheels, ride height, so on and so on and so on. I'd bet money that driving any 10 V8 Z's would seem like driving 10 entirely different cars. I would *guess*, based on my short experience with the car post-V8 / pre-suspension mods that the mild low speed understeer (push) would be *slightly* reduced; though with the radically higher power levels, oversteer (rear-end coming around) is instantly available at any time. At higher speeds, the rear end is much more willing to come around. I have little experience with the '72 with regards to roll reduction, as I installed a 7/8" anti-sway bar the same time as the motor; though with the front bar and no rear, as well as a 2" reduction in ride height, I experience virtually no body roll.

 

How does it feel at normal highway speeds, as well as higher than normal speeds, hehe.

Extremely stable and well mannered at any "normal" speeds. Kamanari air dam and lowered ride height mean I have experienced none of the dreaded "front-end-float" at higher speeds, but I haven't really pushed the envelope.

 

What about around town driving.

The steering is heavy - you've always got to be moving a bit when you're parallel parking. Parking lots are a problem, both because of the heavy steering thing, and the speed bumps thing. For other impressions, see "transmission" notes, below. Also, you *must* replace the factory seats. They will cause scoliosis if used too long.

 

Noise, road vibrations, reliability.

It's a noisy machine - it's 35 years old, and it's got a monster in its' pants. *And* it was never a tightly buttoned ultra exotic in the first place. That said, I'm installing a whole bunch of sound-deadening material (in conjunction with an a/c install). I'm also considering a more rational muffler setup. What can I say, I'm old. Reliability is a relative thing: the car is down a lot, but that's mostly because I'm always "puttering" on it. Right now, the dash is out for my a/c and sound-deadening install. At times when I needed it to work, it has, but that's me.

 

Gearing, does the 6spd feel like too many gears, or some that you maybe just bypass sometimes? Anybody do a 6spd and wish they did the auto, or vice versa?

The thing about the T56 is, there's a lot of rowing going on. It's not a "problem", really, it's the nature of the beast. Sports cars have clutches, after all, and that's great; but a 400 hp engine in a 2500 pound car doesn't *need* all those speeds. Under normal driving conditions, I generally shift 1-3-5, and sometimes 6, which puts me 'way under 2k RPM at any near legal speed. I haven't done the R-200 install yet (it's on the list), so the cruising RPM will change upwards a bit, but the gist of it is that there's a lot of gear shift interaction.

 

What about mpg, a valid concern with todays gas prices.

Pretty good, considering. I generally get 19-21, combined city/country, rational though not "being followed by a black-and-white" driving. Upper 20's on the highway, again, pretty rational but not entirely legal style. Put the foot down and those numbers go straight to, well, heck.

 

On balance: If I were considering doing it again, and especially if I was thinking about building a daily driver, I would change my priorities a bit. First, I wouldn't put so much effort into power. I went overboard, and have gotten a scary-fast machine, and not always scary in a good way. There's nothing like unexpectedly swinging the rear end out at triple-digit speeds. I'd find a fairly high powered motor *in its stock form*, and leave it unmolested. I would seriously consider one of the newer automatics, cause the romance starts to go away when your old left knee starts barking at you every time you take off from a stop. I probably wouldn't lower it as much, nor would I have put such a complex air dam (I've cracked it twice, now). These are all "livability" things that don't seem important in the heat of designing a world-killer, but make the difference between owning a "impressive toy" and owning a "real car". But it's up to you; I've done it already, been there done that, reached the top of the mountain, seen the promised land. It would be my *second* Z project, not my first. And as we all know, you always remember your first the best.

[Guest Joek]

Thanks for all the great info so far. For my uses, no it won't be a daily driver, I don't think a Z would look right with a lumber rack fitted to it, but that's just my opinion. I envision more of a dominant street toy, occasional autocross use, and the occasional long trip with a small trailer (less than 1000lbs).

 

So, autox for fun, but no need to be competitive, since then I'd end up with a car that just isn't any fun to drive anyplace else. I don't really need to feel like I just got punched in the kidneys everytime I go buy milk. Car also can't be too low, cause I have a driveway issues, that can't be helped. I think I could probably fit a small airdam, but for my car, I prefer the lines without side or rear skirts. Will probably go ZG flares though for some extra rubber.

 

I'd certainly go with the stick, but have never driven a 6spd and it just seems like it would be excessive. Also sounds like many people never even make it into 6th. But I am of the personal opinion that sports cars should have manual transmissions.

 

For the longer trips, the wife and dog would be with me, and the trailer would be camping gear. The wife isn't going to be happy if she can't talk at me, I mean if we can't converse. So lots of dynamat will be in order. Any idea if header wrap cuts down noise, as well as heat? I prefer more of the stealth mobile anyway, so will probably have big mufflers underneath. I assume once I get the car sorted, it should be about as reliable as an '02 camaro. Only reliability issues I've ever had with my numerous Datsuns has been engine related. Well, once I blew up the rear end in my 510, but that was caused by a smoking issue the rear tires were having, if you know what I mean And yeah, I'm thinking low mileage LS1 pullout to straight drop in. It seems like 7.5lbs per HP should be enough to start.

[strotter]

Yeah, getting the woman to travel in the "toy" is a challenge. Mine won't; she's convinced we'll be stranded somewhere inhabited by murderers and mutants. She doesn't differentiate "car won't run 'cause it's broke" (which is actually rare) and "car won't run 'cause I took it apart for fun" (which is actually common). Also, as you implied, women in general are not impressed by the "spirited" exhaust note, or the idiosyncratic exhaust smell. She isn't insisting on a luxo-boat (she loves her Civic), but she expects a certain "professionalism" in the details. To tell you the truth, so do I; living with my toy is sometimes demanding. Make no mistake, I enjoy my car with fervor, relish schooling some fool on the advantages of skills with hand tools over skills with a checkbook, but the every day comforts are, well, comforting.

[Jerminator96]

I wouldn't worry about having 'too many gears' with the 6spd, you don't have to use all of them. In my Z28 I used to run first gear to redline to smoke some fool in his riced out honda then throw it in sixth and cruise on. Sixth gear is definitely not a performance option, but with a .5:1 ratio I would get 28mpg on the highway. I used it all the time in that heavy car so I would imagine I'll be using it all the more often in my 240Z.

[Phantom]

I have 28,000 miles of experience in my LS1/T56 280Z. The car has mainly been a daily driver but it has been driven hard at Texas Motorplex and at Texas Motor Speedway so it has seen duty on the 1/4 mile track and on the crooked track.

Balance wise the car weighed 1,400 lbs on the nose and 1,430 lbs on the tail with 3/4 tank of gas and the MSA Aero II ground effects package with the LS1 & T56. The LS1 is lighter than the L28 and mostly sits behind the f4ront axle and obviously sits lower than the L28. It required no front suspension modifications. The T56 is a monster and is what added the weight to the car and also moved the weight toward the rear.

You will never not be able to know what your motor is doing. Even with additional sound proofing I hear the sing of the LS1 at all speeds.

tight track handling will pretty much be the same as with the L28 except for the ability to throttle steer which will be much greater with the LS1. Weight is essentially the same so cornering is very close to with the L28 and so is braking.

High end stability is again the same as with the L28 which is totally dependent on suspension and any ground effects/aerodynamic work you may do. If you have specific questions feel free to email or PM me.

Bill

[Gollum]

Regarding the T-56. Dont forget that this tranny isn't a single overdrive unit, it's a double over drive tranny. So 1st-5th aren't much different in gearing than most gear boxes.

 

But the second overdrive isn't very usable unless you're using at least 3.545, or 3.7 and up.

 

You can use this calculator to estimate RPMs at certain speeds.

 

http://www.geocities.com/z_design_studio/

 

I've personally never been in a LS1 powered Z but I've seen a few in person. Maybe someone else here in the bay area will be willing to give you a ride sometime.

[Phantom]

Gearing wise - with the torque of the LS1 and the light weight of the Z you could drive all day using only 2nd and 5th - but what fun would that be? I use all 6 gears running my 4 mile one-way drive to work. Heck - I even get into 2nd and sometimes 3rd gear in my driveway since it's 3/10ths of a mile long.

With stock diameter tires and my 3.70:1 LSD the car will climb out from under me, melt the tires in 1st, and maybe stay hooked in 2nd. It will then idle down the road at 40 mph in 6th at 1,000 RPM. Yes, it will drive and even climb small hills in 6th at 1K rpm. The totally stock '98 LS1 on stock diameter/width tires will turn a 12.9@110 in the quarter which is much slower than most of the other LSX equipped cars here and it takes the first 4 gears to get it done. A lighter car would need 3.54 gears or use 5th at the end - or else go beyond 6k on the tach. I ran a 13.3 using a 2nd gear start.

 

If you are doing autocross you can have a crazy time staying in 1st & 2nd or make it easier on yourself by running in 2nd. Top end in 3rd with my gearing is about 90 mph and 60 in 2nd - that would be using a 6,000 rpm shift limit.

 

MPG - I've maintained a logbook on my car for 16 years and have a totally anal method for ensuring accurate recording of my mpg. Because of that I can tell you that it got 10 mpg when I was running it at Texas Motor Speedway and that it gets 24-25 mpg cruising at legal highway speeds.

In combined city/hwy driving where it can get warmed up good it averaged 19-20 and for short, cold weather city trips it got 15-16. My car, however, weighs an even 3,000 lbs because of the comfort items I've added - A/C, soundproofing, leather interior, 500 watt sound system, etc. - so a lighter weight version would do slightly better around town - but probably not on the highway.

[Guest Joek]

Thanks Gollum, I hadn't realized that both 5th and 6th were OD ratios. That link seems like ti would be nice, but my computer won't install the little program to run the graph because it doesn't recognize the publisher. I'm a long way off from the need to figure out final gearing though. I like the idea of getting a ride in someones, maybe Strotter will appease me, I can do a little wine tasting while I'm at it.

 

Phantom, I'd think the car would handle better with a little more weight at the back, lower center of gravity, both from the lower engine, and the heavier tranny. I have read alot about handling and center of gravity, and will be the first to admit that most of it is over my head but that heavy tranny, I'd think the car starts to handle more evenly. Don't most high end front engine sports cars have the trannies mounted at the rear to divide the weight up more evenly. With 28k on your swap, any comments on reliability?

 

Strotter, I guess I'm pretty lucky in that my wife isn't afraid of the car breaking down, she considers it all part of the adventure. But if I go more than 10 mph over the speed limit, she stops breathing. I have to slowly creep up to 85 on longer trips, so she doesn't notice. I'm also the do it myself type. I appreciate those with more disposable income than I. In the long run it makes parts cheaper, or even available, to me . I do sometimes wish there were 2 classes at car shows. One for the guys who did it all themselves, and one for those that had pros do it. Though I'm happy to take 2nd place when the guy who took 1st spent 50K getting his car restored and I spent about 5K restoring mine myself.

[johnc]

Phantom, I'd think the car would handle better with a little more weight at the back, lower center of gravity, both from the lower engine, and the heavier tranny. I have read alot about handling and center of gravity, and will be the first to admit that most of it is over my head but that heavy tranny, I'd think the car starts to handle more evenly.

 

Don't get yourself hung up on weight distribution and cg. That's one of those finer points of making a car handle and with most production based vehicles you can only change, at most, 5% which isn't that big a deal. A stock Integra Type R (63% F/ 47% rear) on sticky tires will beat 90% of the 240Zs here on this site at an autocross.

[heavy85]

'02 LS1 in light mostly stripped '72 240Z will light-up second gear at will. I use 6th anytime on the highway. 6 speed is not excessive but then again my DD also has a 6 speed. Main difference between L and LS is the huge grin on your face when you hit the loud pedal. Exhaust smell is identical either way (I recommend cats which I will be adding this winter). Autocross takes finesse even with full slicks. I launch basically at idle and manage wheel spin through first. Started with 3.9 from the L days but that's just silly. I'm running 3.7 now but should probably put in the 3.5. It's really no louder than the L was but that's probably because I have zero insulation or even carpet. No drone or annoying noises.

 

Cameron

[Phantom]

Reliability. Remember - mine was professionally installed by JCI and they are totally anal about their workmanship. That is why the conversion came with a 12 month, 12,000 mile warrantee. In 28,000 miles I've had both fan relays suffer infant mortality but have been fine since. I also had a starter wire that was too close to the exhaust fry. Other than that reliability has only been affected by abuse - ie: broken half shaft u-joint from excessive wheel hop brought on by excessive use of the loud pedal.

Please note the front/rear balance of the car I talked about in my first post. The car started with a 50/50 wieght distribution and then became tail heavy beacause of the T-56. Not a bad thing if you're a straight-liner and really not a bad thing because it's so small for other applicatons.