Shovels Posted January 1, 2006 Share Posted January 1, 2006 I can confirm that circa 500bhp makes a very fast road car - tbh it'sonly on really long open straights that I wish I had more power. On the twisties is plenty quick enough. I would also love for someone to explain exactly what they mean by 'lag'. Are you talking about spool up time, or the time it takes for the turbo to kick back in after a gear change? The only reason I ask this is - Yes my T78 takes a while to spool up, but lag between gear changes? Nope - Goes like a rocket! Quote Link to comment Share on other sites More sharing options...
JohnA Posted January 1, 2006 Share Posted January 1, 2006 700 bhp and relialbility will not go hand in glove,and most people could not afford it,.. exactly. The term 'reliability' takes a large pinch of salt in the context of this sort of horsepower. For starters, we're talking a car that does easily low 10s. What sort of clutch or gearbox can take this sort of abuse without breaking sweat? The whole engine would have to be rebuilt from the ground up if it's meant to be used everyday, start-stop traffic, pump fuel, etc. Not cheap. Quote Link to comment Share on other sites More sharing options...
Lucifer Posted January 1, 2006 Share Posted January 1, 2006 Here is a costing wensite for my current build, might give you an idea of whats needed, Might wand to add 20% for things ive forgotten http://www.southwestsupras.com/supra.htm Quote Link to comment Share on other sites More sharing options...
Rich Posted January 1, 2006 Share Posted January 1, 2006 I can confirm that circa 500bhp makes a very fast road car - tbh it'sonly on really long open straights that I wish I had more power. On the twisties is plenty quick enough. I would also love for someone to explain exactly what they mean by 'lag'. Are you talking about spool up time, or the time it takes for the turbo to kick back in after a gear change? The only reason I ask this is - Yes my T78 takes a while to spool up, but lag between gear changes? Nope - Goes like a rocket! hi shovels,I too am running T78 , what mm is your T78? Quote Link to comment Share on other sites More sharing options...
Matt Harwood Posted January 1, 2006 Share Posted January 1, 2006 I can confirm that circa 500bhp makes a very fast road car - tbh it'sonly on really long open straights that I wish I had more power. On the twisties is plenty quick enough. I agree. a genuine 500bhp is a huge amount of power for a road car. Bear in mind that with this sort of power you will never get proper traction in any kind of damp weather, in fact you'll can get traction problems on a dry day too! I think half the problem is that there are too many huge power figures thrown about these days. Everyone knows of someone thats running 700bhp in there mates car, there are 1000+bhp cars being used as daily drivers in the states, and Max Power will talk of silly BHP numbers all day long. So when some claims to have 500 bhp, it's almost sniffed at I would also love for someone to explain exactly what they mean by 'lag'. Are you talking about spool up time, or the time it takes for the turbo to kick back in after a gear change? IMHO, it's when you stick your foot to the floor at 3000rpm, and not much happens for a few seconds until your car reaches 4500rpm and all hell breaks loose. (I'm guessing 4500rpm for a T78 btw) Terry S's car has probably the least lag of any modified Supra I've driven, (possibly comparable to stock at the bottom end!). In almost any gear at almost any rpm, (within reason), the turbo is making a noticable difference almost immediatly. I'd say that's down to his choice of comparitively small turbo, and well mapped ECU, and maybe the VVTi system playing it's part. Whatever the reason, it makes it great fun and a pleasure to drive. The only reason I ask this is - Yes my T78 takes a while to spool up, but lag between gear changes? Nope - Goes like a rocket! And so it should mate Quote Link to comment Share on other sites More sharing options...
Need4Speed Posted January 1, 2006 Share Posted January 1, 2006 Horsepower figures are a bit like stereo outputs. The numbers are getting way out of hand. Quote Link to comment Share on other sites More sharing options...
Lucifer Posted January 1, 2006 Share Posted January 1, 2006 Personally I dont care what anyone says, its all about how it performs...... Quote Link to comment Share on other sites More sharing options...
Matt Harwood Posted January 1, 2006 Share Posted January 1, 2006 Horsepower figures are a bit like stereo outputs. The numbers are getting way out of hand. That's very true. Funny how all the cheaper amps claim the higher figures as if they have something to prove..... Quote Link to comment Share on other sites More sharing options...
Darren Posted January 2, 2006 Share Posted January 2, 2006 Horsepower figures are a bit like stereo outputs. The numbers are getting way out of hand. Drive a 400+ BHP Supra and learn to respect it. BHP is great for bragging down the pub but when you get over 400 into 500 or 600 the car becomes a different animal IMHO and sometimes its more differcult to drive and enjoy Quote Link to comment Share on other sites More sharing options...
jason m Posted January 2, 2006 Share Posted January 2, 2006 I can vouch for Terry's car having been in it on the strip and the road. Nice wheels too;) Quote Link to comment Share on other sites More sharing options...
Shovels Posted January 2, 2006 Share Posted January 2, 2006 I agree. a genuine 500bhp is a huge amount of power for a road car. Bear in mind that with this sort of power you will never get proper traction in any kind of damp weather, in fact you'll can get traction problems on a dry day too! Traction is a problem in the wet, not too bad in the dry, and that's why any more you're gonna be needing some sort of advanced traction control system, or a light right foot. IMHO, it's when you stick your foot to the floor at 3000rpm, and not much happens for a few seconds until your car reaches 4500rpm and all hell breaks loose. (I'm guessing 4500rpm for a T78 btw) Yep - That's about when it starts to pull like a train. hi shovels,I too am running T78 , what mm is your T78? Urmmm... Dunno Richie. How can you tell? Is it written on it somewhere? Quote Link to comment Share on other sites More sharing options...
Rich Posted January 2, 2006 Share Posted January 2, 2006 Traction is a problem in the wet, not too bad in the dry, and that's why any more you're gonna be needing some sort of advanced traction control system, or a light right foot. Yep - That's about when it starts to pull like a train. Urmmm... Dunno Richie. How can you tell? Is it written on it somewhere? Not sure where that measurement is from,they do a few different sizes ,starting at 17mm up to about 21mm I have been told.my T78 is not that bad for lag as it is the smallest one they do .it comes on full chat around 4100 rpm. Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted January 2, 2006 Share Posted January 2, 2006 Not sure where that measurement is from,they do a few different sizes ,starting at 17mm up to about 21mm I have been told.my T78 is not that bad for lag as it is the smallest one they do .it comes on full chat around 4100 rpm. I'd be suprised, but even so thats later that a 67 P trim. Quote Link to comment Share on other sites More sharing options...
JohnA Posted January 2, 2006 Share Posted January 2, 2006 That's very true. Funny how all the cheaper amps claim the higher figures as if they have something to prove..... How true, he he... I had a friend visit the other day, and he is used to the ridiculous car hifi 'megawatts', and what's worse - believes them. He then went on to express his surprise at the lack of power of my home system (which is grossly overpowered by anyone in the know) He pointed at one of the monoblocks: how many watts it it? 200 I said. "Pffff... on my car I've got1000w amp" he said, and truly believed it (he thinks he's deeply into car hifi, so I expected him to know better) I then explained that half-decent 'home' hifi measures power only RMS with very low THD etc, but he wouldn't have it. That monoblock will exceed 200w at 8Ohms, 400w at 4Ohms and max out at 800w at 2Ohms (hence it's hard to lift) All with THD and IM distortion well below 0.01%. Then there is the other channel. He'd have none of it --- he trully believed that the piece of crap in his boot with 1000 or whatever claimed musical 'watts' for both channels was far more powerful because it makes the (car's) windows rattle:read: . So we left it at that. Had we put the two side by side the difference would be obvious - but we was not comparing like with like, and fell for the marketing hype and fancy 'peak-to-peak' figures. Those mean nothing in real, sustained use. It's the same with "600+bhp" supras you see touted around in US forums, like they grow on trees over there. If you were to bring one over to the Pod, fill it with local Opticrap, everyday tyres and give it a go, I'd bet money that it wouldn't be the "10sec" car their owners brag. Quote Link to comment Share on other sites More sharing options...
Ian C Posted January 2, 2006 Share Posted January 2, 2006 I had a shufty at some datalogs: The upshift from 2nd to 3rd put the revs at 4600rpm, and it took 0.8s to hit 1bar of boost. The upshift from 3rd to 4th put the revs at 4800rpm, and it took 0.4s to hit 1bar of boost. The upshift from 4th to 5th put the revs at 4800rpm, and it took 0.4s to hit 1bar of boost. The lag of a specific type of turbo is mostly affected by what rpms you are at and what load there is on the engine (i.e. what gear you are in) when you boot it. Looks like with a T67 the minimum lag time is 0.4s to hit 1bar. If you floor it in 6th at 2000rpm it takes about 18 seconds to hit full boost, unsuprisingly Anything about 4000rpm and it's pretty much instant-on. In fact it smooths the power delivery out nicely to avoid shocking the drivetrain or breaking traction just through jerky power delivery. -Ian Quote Link to comment Share on other sites More sharing options...
Rich Posted January 2, 2006 Share Posted January 2, 2006 I'd be suprised, but even so thats later that a 67 P trim. I have no doubt the T78 is laggier than a T67 due to it being old technology.but I do think that there is a lot of exageration when it comes to the lag on the T78,the T88 is probably the reason people think of serious lag. Quote Link to comment Share on other sites More sharing options...
Jurgen-Jm-Imports Posted January 2, 2006 Share Posted January 2, 2006 my t78 has no lag:nyah: Quote Link to comment Share on other sites More sharing options...
jagman Posted January 2, 2006 Share Posted January 2, 2006 very good analogy with the HI-FI ,its a bit like having a 10 watt speaker,and soldering in a 1000 watt resistor on the back -and hey presto- ive got a 1010 watt speaker --beat that! , If it was easy to double the bhp on a 300 bhp stock engine,how come porsche,jaguar,bmw,etc find it so expensive to make their race cars?surely they can just bolt on a big turbo,and add an egt guage for peace of mind Quote Link to comment Share on other sites More sharing options...
Lucifer Posted January 2, 2006 Share Posted January 2, 2006 Drive a 400+ BHP Supra and learn to respect it. BHP is great for bragging down the pub but when you get over 400 into 500 or 600 the car becomes a different animal IMHO and sometimes its more differcult to drive and enjoy Never a truer word said. Quote Link to comment Share on other sites More sharing options...
JohnA Posted January 2, 2006 Share Posted January 2, 2006 .,its a bit like having a 10 watt speaker,and soldering in a 1000 watt resistor on the back -and hey presto- ive got a 1010 watt speaker --beat that! , The power rating of speakers has always been a mystery to me (rather the significance of it in people's minds) It's just the approximate ability for heat dissipation by the coils. So what? Bragging rights for the pub? What if it is a 10KW speaker and only produces 50db peak. Is that an impressive spec then? (impressive for an electric heater perhaps:haha: ) OK, throw in full racing gas, drag tyres etc and come up with fancy numbers. How does that relate to real life then? Quote Link to comment Share on other sites More sharing options...
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