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The mkiv Supra Owners Club

Spend thousands on a big single, to become slower than a T.T.


David P

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Most of my experience is with engines on engine dynos, but for sure, a hub dyno takes the tyre slippage / traction element out of the equation, and is the way forward for high torque cars, IMO. I have seen the apparent timing and fuelling needs of engines run up through the rev range with logged AFR on a few fast dyno "pulls" and I have seen how these change when the engine is loaded up for several seconds at a fixed or slowly climbing RPM under full boost around peak torque. The need for more fuel as internal temps rise, and often less timing can be quite dramatic. A lot depends on the basic design of the head and waterways, and in the pistons and rings ability to transfer crown heat to the water, in other words the ability to sink rapidly climbing temperature effectively. This was the reason I spent a huge amount extra for forged pistons with stock like oil cooling of the crown. They make a big difference in removing heat under duress. I have not seen any forged aftermarket pistons for the 2JZ engines with this feature. Their manufacture is tricky, slow and thus expensive.

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Is there much difference in acceleration between a bpu supra and say a 600bhp single from 0-80mph in real road conditions? With the same driver. I ask because I know it's difficult to put the power down at lower speeds?

 

Im confident in murdering (and have done many times) any bpu on the street at any speed.

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Is there much difference in acceleration between a bpu supra and say a 600bhp single from 0-80mph in real road conditions? With the same driver. I ask because I know it's difficult to put the power down at lower speeds?

 

Hugely varying factors.

 

With stock wheels and tyres you can max out the ability of a TT to go from 0-60 in stock form. This would mean hitting 0-60 in approx 4.9 seconds. No matter what you do power wise you are going to be restricted from then on in by the traction. BPU cars will hit 0-60 in the same time, as will a single. It will get progressively harder, rather than easier, the more power you throw in there though as traction will become a greater factor.

 

If you take a fully setup drag car with a stock engine in it, then move it to bpu then move it to single it will get progressively faster at each stage.

 

That's what the sensible discussion in this thread has been about :)

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Is there much difference in acceleration between a bpu supra and say a 600bhp single from 0-80mph in real road conditions? With the same driver. I ask because I know it's difficult to put the power down at lower speeds?

 

I'd say, tyres, suspension, wheel size, clutch, auto/man and driver would have the greatest difference

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This was the reason I spent a huge amount extra for forged pistons with stock like oil cooling of the crown. They make a big difference in removing heat under duress. I have not seen any forged aftermarket pistons for the 2JZ engines with this feature. Their manufacture is tricky, slow and thus expensive.

 

It may be worth discussing this with the Drifty chap with the Cosworth sponsored Supra. He's (apparently) giving input to newly developed Cosworth parts for the 2JZ, so this may be something they would consider, especially considering they target the top end of the market.

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Hugely varying factors.

 

With stock wheels and tyres you can max out the ability of a TT to go from 0-60 in stock form. This would mean hitting 0-60 in approx 4.9 seconds. No matter what you do power wise you are going to be restricted from then on in by the traction. BPU cars will hit 0-60 in the same time, as will a single. It will get progressively harder, rather than easier, the more power you throw in there though as traction will become a greater factor.

 

If you take a fully setup drag car with a stock engine in it, then move it to bpu then move it to single it will get progressively faster at each stage.

 

That's what the sensible discussion in this thread has been about :)

 

What mods are available to increase traction of the line? Tyres,suspension and LSD I am aware of,anything else that can improve traction?

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Most of my experience is with engines on engine dynos, but for sure, a hub dyno takes the tyre slippage / traction element out of the equation, and is the way forward for high torque cars, IMO. I have seen the apparent timing and fuelling needs of engines run up through the rev range with logged AFR on a few fast dyno "pulls" and I have seen how these change when the engine is loaded up for several seconds at a fixed or slowly climbing RPM under full boost around peak torque. The need for more fuel as internal temps rise, and often less timing can be quite dramatic. A lot depends on the basic design of the head and waterways, and in the pistons and rings ability to transfer crown heat to the water, in other words the ability to sink rapidly climbing temperature effectively. This was the reason I spent a huge amount extra for forged pistons with stock like oil cooling of the crown. They make a big difference in removing heat under duress. I have not seen any forged aftermarket pistons for the 2JZ engines with this feature. Their manufacture is tricky, slow and thus expensive.

 

 

I always wonder at the amount of times i read on various forums about how somebody spends lots of money on all the perceived "top spec" parts at the time, has the engine built, dyno'd and mapped, only to find it fails the first time its run long and hard,

Having a quick car with all the bragging rights/popularity it attracts, is all very well, but most of the proven big power cars spend most of there time on the track or strip in relative anonymity.

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What mods are available to increase traction of the line? Tyres,suspension and LSD I am aware of,anything else that can improve traction?

Not only tyres, but drop wheel diameter down to get more sidewall.

 

Although RLTC does not improve traction, it will make those of us who are not gifted racing drivers make best use of available traction

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What mods are available to increase traction of the line? Tyres,suspension and LSD I am aware of,anything else that can improve traction?

 

Launch control helps some, auto boxes tend to be faster in the 1/4 mile with high stall (due to accurate changes etc).

 

I've only ran the 1/4 mile in a clio and an MR2 so I'm not the voice of experience. Better to speak to peope like Jamie, Dude, Gaz, Brian etc who have regularly ran the 1/4 mile and gotten VERY respectable times.

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Is there much difference in acceleration between a bpu supra and say a 600bhp single from 0-80mph in real road conditions? With the same driver. I ask because I know it's difficult to put the power down at lower speeds?

 

Potentially a huge difference, but it all depends how each car is setup. If the TT has good suspension setup, tyres, traction control, etc. to get the power down and the single turbo is struggling for grip then the TT may be the faster car. If both cars have equally good setup then the single turbo car would murder the TT from 2nd gear onwards.

Edited by Nic (see edit history)
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And there is 13 second, 14 second and 15 second NA's that are quicker than a lot of the TT's listed, Are you really telling me you dont understand why some are quicker than others? just look at the top cars listed in the TT section, all of them are setup for drag racing, compare them to ST's that are setup the same.

 

I understand only some of drag racing techniques, and when looking at a Club list that shows 92 T.T's, of which 85 (78%) of them were faster than the slowest single, and only 7 (19%) of the 34 singles were quicker than the fastest T.T.

 

I am curious?

Edited by David P (see edit history)
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I understand only some of drag racing techniques, and when looking at a Club list that shows 92 T.T's, of which 85 (78%) of them were faster than the slowest single, and only 7 (19%) of the 34 singles were quicker than the fastest T.T.

 

Am I the only member who is curious?

Your comparsion is back to front, why compare TT against the slowest single then singles against the fastest TT? It's not even a fair ncomparison

 

100% of singles are faster than the slowest TT, 81% of statastics are made up on the spot, WTF don't you get about the car setup and driver being WAAAAYYYY more important than ny feckin turbo setup

 

Actually fuck this everytime I read one of your posts my skin crawls, easy fix for that

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I understand only some of drag racing techniques, and when looking at a Club list that shows 92 T.T's, of which 85 (78%) of them were faster than the slowest single, and only 7 (19%) of the 34 singles were quicker than the fastest T.T.

 

Am I the only member who is curious?

 

No I find it interesting also,not sure bout the thread title though!

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Launch control helps some, auto boxes tend to be faster in the 1/4 mile with high stall (due to accurate changes etc).

 

I've only ran the 1/4 mile in a clio and an MR2 so I'm not the voice of experience. Better to speak to peope like Jamie, Dude, Gaz, Brian etc who have regularly ran the 1/4 mile and gotten VERY respectable times.

 

I've only ran an impreza at a rwyb day,although I got a 11.5 best time,ruined a £700 clutch with 3 launches though :)

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