Just wanting to have a bit of a discussion about power relating to a stock TT. obviously a worked tt will have a different power output. I've been trying to work out where the power really is in the Z most of the time i've been driving it. when it was an NA, it was clearly there in the lower range of the power spectrum, mostly tuned to have good take off from a standing start, but then when I got over 140 it definitaly started to flatten out. so, for an na, the power was there from the lower speeds and was good for 0 - 150+ driving my (stock) TT, i'm not overly thrilled by the take off, but lets face it, we arent talking about a pristine motor here, I am lacking a bit of compression and loosing some power in the drive train. but I was also in the NA and that had a great take off. I think there are two ways to drive the Z. you can take it like a standard V6, and drive around barely going over 3500 revs, but then acceleration will never be that great and you're not really making the most of any boost that is generated. the other way to drive it, which doesnt work around town, is to move the rev range up higher, change later and work around the 2500 - 5000 rev range, then you really start to get more acceleration especially through high speed limit traffic areas, but it also sounds much more like a sports car than just a nice throaty sounding v6. the only thing I have against driving it in a higher rev range is that is can come across and more obnoxious, like when I was working at autobarn, we used to make fun of those guys taking off from the lights hitting 5000 revs in a 60 zone. but realistically, in the Z, if you don't go that high (maybe in 2nd) then you are losing a lot of momentum changing to 3rd so soon. obviously these arent' meant to be driven as town cars. and they arent tuned for instant power at take off (as stock tuning) which is why a standard commodore v6 or even most hatches are faster off the lights unless you want to make a ton of noise and really go through the rev range of the Z. not that i've tried it, but I'm pretty sure on a good straight, the commodore may pull pretty easy off the line, but if you kept the Z above 3000revs and changed late, you shouldnt have a hard time getting ahead of the commodore. I suppose the reason I'm talking about this, is because sometimes I feel a bit dissapointed in the 'performance' of the Z. but it just when I am feeling like there is no choice but to overhaul and drop in some 600cc injectors and maybe even a stroker kit, I take it out for a run and it just drives smoothly, so i think that its performance can be heavily influenced on the technique of the driver. another thing to say about the VG30DETT, is that it never lacks torque, even if it is having a bad week for acceleration, there are more than a few hills around where I live and some are quite steep (most cars creep up barely hitting 40) but in the Z you wouldnt even know you were on an incline. its' one hell of a torquey engine. but lets face it the 300 is quite a heavy car to have to pull, unlike some of its smaller nissan buddies. I'm not sure what HP i'm putting out, and I doubt it would be anything spectacular, probably more closer to the 200hp side if you put it on a scale between 200 and 9000hp. so maybe for a 24 year old stock tt, i'm getting my money's worth in terms of acceleration from the Vg. if I had the money it would be interesting to pull it off the road for a bit and rebuild the engine, get compression back up and upgrade a few things with bigger injectors, maybe street cams, some head work and a proper street tune, then see how big an improvement this would have over how it is running at present. especially it would be good to see more power in the lower range than just in the 3000 or 4000+ arena. another thing to consider is how powerful other cars where back in 1990 and what the Z had to compete with. Yeah a modern commodore can probably pull as good as the TT up to a certain point, but the Z back in 1990 would have killed any VN that was fresh off the production line. so yeah, its a sports car, but it's also a 24 year old almost classic sports car. a lot has improved for stock engines in those 24 years. in conclusion, yeah, i may be a little disapointed in the 'performance', but the VG with the right exhaust does sound like one mean sounding engine and doesnt fail to turn heads idling around any car park (under cover car parks are even better) and it always gets attention driving through town, so I suppose performance isnt everything. But, if I had a spare 10 or 15 grand for that engine upgrade..... well, I would probably like driving it even more than I already do..... Vote for Pedro!
The difference you're feeling pre boost could be due to 4.1 gears vs 3.7 gears. The 4.1 gears in the NA would accelerate better off the line than 3.7 gears pre boost.
man yours must be in poor condition. a stock TT should have no problem accelerating easily, especially an auto, I find TT autos to have v8 like acceleration at like a quarter throttle, as for a modded TT manual, mine accelerates absolutely effortlessly. Sometimes i will drive to work and realise i have not even hit boost once, if i am hitting 5000rpm in second, even part throttle i will be turning the tyres. I do drive an old rangerover with a warm 302 windsor so i do know the torque and instant power you are talking about. and on the other end of the scale, my RB20 powered bmw is a hooligan to drive but it needs alot of revs. You think a vg is bad, come up to bris and drive this thing. lol
I dont know mate... I owned a 2 seater NA for nearly 10 years. Then went looking for a 2+2 TT. I test drove the TT I have now and bought it that day. The acceleration of the TT was just so much more intense compared to the NA. Both cars manual, both with healthy engines and the NA being a 2 seater is lighter. I loved the NA (still do, I should never have sold it and kept both), but a stock TT is just a different beast to an NA. I find with the Zed, both NA and TT, although I think more so with the TT, that 1st gear is just too "short". You just dont seem to get anywhere. But then once in 2nd gear, thats when the boogy starts. 2nd gear is the winning gear, and you can trash that baby to at least 100km wgen needed ..
ah, now you are just making me feel bad. honestly I expected more from the TT. I've had some people drive it and say it's about what they put out. but I'm not convinced. compression is not great, but I don't think it should stop me from getting off the line that much. to me, I just feel like if I do want to get a good launch, I need to push the VG more than it feels it should go... you know what, if you all are saying that a tt should launch pretty well and mine is that piss weak. maybe my whole clutch setup is ****ed after all. it would be good to find out just how much I am loosing through the box. as for the gearing, I thought the boxes were the same, but the difs were different? I have an na diff still, so I should still be getting NA ratios right?
mine is a manual, once I'm going, I accelerate pretty well (when it wants to) but I don't really have another good Z to compare the acceleration to. if I had the money i'd take it to chequered tuning and get the whole thing checked out, but knowing what does have to get done, plus the tune. it won't be cheap I don't think.
WHen you say stock how stock...... original everything - exhaust, wheels, boost...... or stock engine but some boltons and a bit of boost?, my last engine had manual cams manual turbos and auto tranny, running 12 psi on a single 4"od to the diff and 4"id after 2 1/2 off the dumps, and an ebay chip (how it came to me) 165 psi comp on 1,2,3,4,6 pistons 125 on 5 would drop back at 100kms into whatever gear it supposed to go to and launch sideways on stock 16's with average tyres if I nailed the right foot. I have not really tried the new engine but it has auto cams and I dont think it will quite do that. But I have had a few V8 lovers more than surprised at how much pull off the mark the turbo'ed v6 has.
Any v6 won't make peak power or torque until 4500-5500 Your turbos won't add a shit tonne of Powah until 4000 rpm either. You could grandma around at 3500 rpm and you'll be disappointed. I rev mine almost to 7k and loose traction in second at 90kph. And it pulls the same from 50 - 190 kph until I kick it into 5th. Then it slows off a little I feel perfectly fine overtaking 7 cars on crap tas roads ( providing I can see far enough aNd its safe to do so) Mine is stock apart from the forged rods + pistons Slaughters my mates 2008 xr8 and my other mates vy ss You might have a few niggling issues holding you back, get one of the vic lads to sort you out. Or you have a driver issue Slam that foot down...
Your experience of driving a TT is very different to mine. I don't have to go anywhere near high rpm to get acceleration that blows away your stock (new) commodore. My best acceleration is in the mid range so much so that I change up a gear to keep in the mid range where the torque is rather than go to high rpm. I've got 130 rwkw at 3000 rpm which is more than most NAs Z32at any rpm - and more than most big turbo +400rwkw monster Z32s). At high rpm I have 271 rwkw. OK maybe I'm one of those "with a worked TT with a different power output" that you mention. So why don't you join us? My mods are not that drastic, all I have is stock injectors, stock block, stock looking turbos (possibly non-stock core - high flowed). I haven't done anything as drastic (or expensive) as putting in a stroker kit. I've just got Selin dual intake, Z1 BA SMICs, Specialty Z expansion dumps, full 3" straight through exhuast. manual boost control at 18 - 15 psi and Nistune. Again the characteristic of my car is that it is a mid-range torquer. I overtake in 5th gear with an absolute ton of torque under 3000 rpm.
+1 for munteds response. Old motor with low compression is not going to pack too much immediate punch, so just put your foot down & enjoy fun launches. Remember rpm + load = boost. You should not be afraid to get up to the higher end of the rpm range, as long as you are at the correct operating temps & you change your oil regularly you will be fine. In my TT (though modded with bigger turbos & an na diff), also manual, I have the most fun in 1st & 2nd gear.
HP? Put it on a dyno. Then you will know how much power you have. By the sounds of it you have less than an NA.
The ZX that I own :zlove: has what I would call a slight tune on a standard manual transmission car with manual turbos with NIStune ECU, pop air filter ,2.5 cat back exhausts. Dyno'd with boost setting 13PSI. Back in the old days we always tuned engines for torque rather than HP .:br: Grunt of the mark and out of corners was the winning form. Torque = lowdown "grunt" HP = top speed. = a long strait distance is needed to peak speed. So a ZX TT with a little bit of work will give you a good slingshot [Holden eat my dust most times ]. eg. 600 RW nm @ 3400RPM. ZX can have problems getting of the mark because of the axle tramp through link windup when under way the 240 :br: RWHP takes over.
Yours is an NA convert, it already has the shorter final drive which means it should accelerate better than a stock TT. Go get a V8 if you want more urgency. Want more low down torque, you need more displacement. I daily a 1.8L MX5, there is no urgency what so ever. Drive the zed, mmm feels good man, doing the speed limit before you know it. Went for a spin in my boss's C63 AMG, even half throttle it has that urgency and it surges forward with a feeling of absolute ease. LS powered commo is a nice cheap alternative. And it'll haul more people more comfortably than the zed.
I did 12.6 with a clutch, catback, ebc (peace of shit greddy) and a tune on street tyres. stock: injectors, intercoolers, dumps, test pipes, engine. thats pretty impressive performance if you ask me and nearly bang on with the new GTS's time. spend the money making your engine healthy with good compression (pistons/heads) and free spinning turbos and you will be suprised. Its all about the base you are working with. vid: http://www.youtube.com/watch?v=n7_jWT1FKUA
reading through all that. here's what I'm thinking. my compression isn't that great, sitting around 120 on all cylinders, plus minus 10. (when I checked it after the conversion) the problem is having power at any low range. on the few occassions I have tried to launch, it has a bit there but nothing exciting. was definitely a better launch in my tired na. so here's what I think. the engine itself is not performing. before the turbo's are kicking in, I'm getting very little power, so I have to wait until after 3000 revs to get the power through the turbos that I probably should be getting from the engine itself. I'm not getting a huge kick when the turbo's do kick in, you almost wouldnt notice it apart from the fact that this is the only time when you start to feel any decent amount of acceleration. I've floored it in 2nd a few times and my ass floats around a bit like it is about to break traction (or does) but i have to be pretty brutal to get that to happen. the setup isnt completely stock, but not far from it. - not sure if manual or auto cams - turbo's are high flowed - ecu is chipped for high flows, but honestly don't know the exact tune, does seem to run better than a stock chip though. for all I know the chip might be setup for bigger injectors or different cams so maybe this might be affecting fuel delivery? major thing I notice is that the freeway onramp near where I live, I know 100% I used to hit 140 coming off the lights there in with ease. it's down hill and I barely hit over 110 in the TT. the reason I'm avoiding getting a dyno is on the last inspection I was told one of the uni joints in the driveshaft needs replacing, I know one of the timing belt pully's was making a tiny bit of noise when we put the timing belt on right the last time it was off, and I'm not sure to what extent my clutch is really playing up so I'm not keen to probably push the VG above 5000revs until all that gets addressed first. but it would be interesting to see what it is putting out, and I don't think it would be all that impressive. Cheers for all the info everyone is putting up, I've just been putting my head down when commo's and HSV's dissapear off the line next to me thinking this was all I had to offer, so looks like there is still some work to do.
