[Mk2] [NA] 150mph in 4th gear from an NA!!!

[Si_Crewe]

Just to add to the concensus...

My N/A will claw its way up to 140 fairly easily in 5th, given a long enough run-up.
I genuinely got a go at this on a track with a 1.5 mile long straight and I changed up from 4th to 5th at the start of the straight, at about 100mph IIRC, and I kept my foot to the floor right to the end of the straight and it was just past 140 on the clock. Must admit, I can't recall what the revs were at the time but I seem to recall thinking that I still had a little bit in hand.

As I've said before, I don't really like revving the nuts off cars. I prefer the feel of mid-range torque.
Even so, at high speed I am sure the TVIS system really does its stuff. The car felt strong and responsive, even at 130+. It felt like it could have used another gear.

I definately don't think an n/a could do 140 in fourth though. No chance. Could a tubby?

As for the "derestricted" thing, he's probably just had jap-import clocks adjusted badly.

*EDIT*
FWIW, my 2 is a jap import and I checked my speedo against a GPS and was shocked to see it's only reading about 1mph high. Even at 70mph it's only 2mph out.

That kinda worried me cos I always worry that I have a "bit in hand" if I ever see a copper or camera.

[mrfil13]

Whats the fastest youve used your gps to check your speed.

On my na when im doing 30mph, gps says im doing 25.
this gap slowly decreases and by the time i get to 70 its near enough bang on, more than that and it will start going the other way, speedo showing slower than really going.

[refo]

Mates just said to me; "Yeah my mr2 goes 150mph in 4th gear"

To which i replyed "what is it? A tubby?"

End up no its a "deristricted" rev 1 NA. WFT is a deristricted NA, what could he mean by this? Obviously hes either making it up or has been told a pack of lies when he bought it, but just to be sure, is there such thing as deristricting a mr2 na?

Now i know hes talking bull, but i want to get my facts right before i go slating him. I dont even think 4th gear can even get close to 150 can it? Never mind the fact that NAs cant even get close to 150 in any gear! (Well maybe the beems engine?)

Hypothetically, how much power would you need to get 150+ out of an NA? Just in case he changes his story to "ohh it was 5th gear"

i've seen an indicated 155 in 5th in my na. but i know the spedo is well out. my mate followed me in his new car and said his spedo was reading 11mph slower when we were doing 90. so i doubt i was doing much more than 140 when my dials were saying 155.

he cant do it in 4th. and if he did then it was down a massive hill with a fooked spedo.

[Rogue]

The rev 1/2 has a better power to weight than rev3/4

No it doesn't.



Patrick

[iblis]

The rev 1/2 has a better power to weight than rev3/4

No it doesn't.



Patrick

Fair enough. I've no problem whatsoever being corrected with a "You are wrong" comment if it's followed by a "because" comment. Nobody's learning anything from that ...

We all know you know what you are talking about, so if it's not related to weight, can you tell us why a rev 1/2 is quicker to 60 even though it has less power? I'm sure there's a multitide here that would like to hear that answer

[Rogue]

Fair enough. I've no problem whatsoever being corrected with a "You are wrong" comment if it's followed by a "because" comment. Nobody's learning anything from that ...

There's a whole other thread on this somewhere, but it basically boils down to the belief that early cars were magically lighter than later cars. I will concede that revision 1 cars didn't have side impact bars, but beyond that I can't see where the extra weight has been added - certainly in sufficient quantity to make a noticable difference to the power-to-weight ratio.

To bring the power to weight ratios down to the same level, later cars would need to be around 100kgs heavier.

We all know you know what you are talking about, so if it's not related to weight, can you tell us why a rev 1/2 is quicker to 60 even though it has less power?

It isn't - even the official figures show the earlier cars being 0.1 seconds slower to 60mph. It's a fairly recent misconception and I've no idea how it got started.

Patrick

[iblis]

It isn't - even the official figures show the earlier cars being 0.1 seconds slower to 60mph. It's a fairly recent misconception and I've no idea how it got started.

Patrick

Thanks for the reply

That is quite a common misconception then. I had always just believed, as you said, the earlier rev cars were significantly lighter.

Very odd. Everyone on here and elsewhere quotes 7.2s and 7.7s, including me ... Don't want to think I've been handing out wrong info. But I don't doubt yours.

I'll have a look for that thread. Thanks.

[Greddy-Matt]

I can understand wanting to know real world 0-60 times on NA's but I think the whole rev1-3+ 0-60 argument is a bit pointless really.

Surely as the performance times between them are so close the biggest factor affecting 0-60 times across all 3 revisions will be driver skill??

[Rogue]

Surely as the performance times between them are so close the biggest factor affecting 0-60 times across all 3 revisions will be driver skill??

Absoloutely. The following video shows the start of an MR2 race at Power Nights. All of the mk2s visible are running the same tyres, revision 3 engines and are limited to the same modifications and minimum weights. They're about as equal as they can be.

http://uk.youtube.com/watch?v=3Yfu2C5Tyng

The camera car gets a better start than all of the others based on nothing more than driver skill.

Patrick

[Rogue]

Correction - car 36 has a revision 2 engine. (Car 10 does as well, but he starts behind the camera car).

Patrick

[CosmosblueMR2]

the biggest factor affecting 0-60 times across all 3 revisions will be driver skill??

or driver's poundage

[nuttasie]

Patrick,Perhaps there are other things which add to the weight also.

for instance-my rev 3's&4 seemed to be abit quiter inside than the rev1(perhaps more sound deadening).

Also my rev1=no p/s,rev3,4 have p/s etc etc.

My rev 1=no abs,rev3,4=abs etc
+ extra metalwork as you noted

All this kind of stuff surely would eventually add up to quite a bit of weight.

All I now is that my rev 1 was defo quicker at pulling away/at the uptake than rev3&4's I have driven.

Do you also now if the power for the rev 3,4's is engine quote or at the wheels,as surely if it is just at fly then the fact that later cars have cats is also going to effect the difference in that so called 20ish bhp between the revs?

edited
Just realized that last paragraph don't make sense,LOL.But we all know that cats affect performance,is what I'm getting at.But not sure how that translates to the cars in Question?

more added as have been thinking on it

when toyota quote the power figures for these cars,were they attained from engine in situ or would the engines have been on stands while they were being developed?This could explain the reason for rev 3's getting the power ike due to cats being introduced thus zapping power so they reworked the engine to get it back?

just random thoughts buzzing round in my head folks,please inform as I am intrigued by this.

[Greddy-Matt]

Your right a cat will affect performance but it is the cat that makes the difference not where the power is measured from if that makes sense

I "assume" Drive Train losses are the same between revisions?

Yes I think your right there, Although it's not just the rev3's that had cats.

But yes its the same thing we see today, as emissions laws etc tighten manufacturers have to make engines more efficient and look at eeking out more and more performance, whilst trying to improve fuel efficiency / emissions etc so they naturally develop and evolve their engines a tweak to the cams here, re-shaping valve stems there etc etc

[nuttasie]

Yes mate,I now cats came in earlier than rev 3 hence people could have moaned about the lack of power to rev1's so they iked the power or they just did it as they wanted the later revs to be as/or more powerful than earlier revs which makes sense.

It wouldn,t be nice nowing that you spent loads of dosh on a new car then somebody in an older model whizz,s past you,LOL.

[Greddy-Matt]

No I can see your point

[rookie-racer]

a few years ago i was seeing a nurse, she worked in stirling, i was based in eninburgh at the time... one fateful night i got a scary call... silence - crying.... me: - hello helloo.... her - jonathan i've been assaulted - me - where are you - her: work..... i'll be right there

after terrorizing north edinburgh and eventually catching the maybury lights i started to driop the hammer... hits to forthroad bridge, turns left towards newton, catches j2 M9 - starts winding her up.

early march, frosty - clean crisp air.... rev two auto... hits the slip road in 2 @70 - motorway - releases her to d with o/d off pennies over 6k revs *EDITED BY ADMIN* iirc - engaged o/d eased off throttle, off the *EDITED BY ADMIN* speedo by now... listened to engine - found a sweetspot at which the car gaine speed ithout trying to commit sipiku by disengaging o/d (would add
40% to revs) - 38 mile trip - 25+ of motorway - tom tom showed *EDITED BY ADMIN* when the car reached its limiter.

i dont know whether this figure was accurate - but it felt right?

car does ninety for just under 3.5krpm on 225/45/16 back tyres... eventually. as ihate thrashbig her - if that helps.

[Leon.]

Your rolling radius is fractionally bigger than stock so that sounds about right, give or take a bit for errors etc.

[Si_Crewe]

Sorry to necropost but this was pretty interesting I thought...

I have an import G-Limited fitted with stock wheels and the speedo has had the electronic kph/mph conversion done.

I just fitted a set of 17" wheels (thanks Luthor1 ) and noticed that they were at least 2" larger diameter than the stock wheels.
I confirmed this cos, after fitting the new wheels on one side, the car was leaning over quite dramatically.

Obviously, my first thought was that this kind of change (haven't done the sums yet) would make a pretty savage difference to the speedo calibration. A 2" change in diamater means the car is travelling over 6" further for every wheel revolution.

So, I stuck my GPS in my MR2 and took it out for a run.
Surprisingly, the GPS shows that the speedo is almost exactly right. It's reading about 5mph low at 30-40mph so I'll have to be careful of that but, at over 50mph, the speedo is exactly right to within 1mph all the way up to, ummm, maximum legal speeds.

Makes me think that, at higher speeds, particularly, my speedo might have been a bit optimistic before even when used with standard wheels. Maybe it's the mph/kph conversion that's dodgy?

[Leon.]

Si, you're aware that the lower profile tyres will lower the RR right, so will counteract the larger diameter rims?

For example 225/50/15 is almost the same RR as 245/35/17...

Also there's tolerance in the speedo from the factory to overread the speed your doing so this also helps.

[nisnos]

fuel to the fire i suppose!
I clocked 207mph on the dyno in a 5th gear pull - but i had 8500rev limit taller tyres and on a dyno there is no wind resistance
i had a few 200+ runs as my 3rd and 4th gears decided to bu88er up and 2nd is too unstable to map in hence using 5th.
needless to say i immediately changed my tyres!