Doughie

"Induction" has got a UK-spec, so he won't get overboost on his car even with a full de-cat and a performance exhaust. Induction - I had a 1995 UK-spec car and did a full de-cat (CW) and a Blitz NUR spec exhaust and it boosted to about 14 or 15psi. you won't get overboost problems on a UK-spec. On a Jap-spec - yes, real possibility, but not the UK-spec.

2lbs of Semtex should work, too.

it must be very interesting as a performance tuner / to take a close-up look at the state of the head-work that Toyota themselves settled on during design of the mkiv. I guess that you can read a lot into that with regards their opinion of where they, as a manufcaturer of a performance car, should "pitch" the cylinder heads of the mkiv in the performance curve. in the end, I think that Toyota has such a reputation with regds. to reliability / longevity that even on a mkiv, their fastest road car, they would always err on the side of caution. I guess ultimately that's the philosophy of their company, and it's served them pretty well. Or is it just a matter of pure economics that manufacturers "skimp" on stuff like head work cos it simply takes along time to do ?

very interesting Chris. what do you estimate are the power / torque benefits of this head work ? My (limited & probably wrong) knowledge of the benefits of head-work / gas flowing etc. suggest that it's a highly time-intensive (and therefore £££ intensive) process which although does offer benefits, might be out-weighed on a turbo-motor by other methods. (on a bhp per buck basis). On an atmo-engine, where there's fewer options for big bhp/torque improvement I guess head-work is higher up the list though ? interested in your experiences etc.

nope i live in London which ain't Ulster. anyway, a bit of Googling, and i find the following site : http://www.dunloptyres.co.uk/data/tyre/60tips.html#tip14 says : "Tyre suppliers commit an offence if they sell a passenger car radial ply tyre which does not have an 'E' mark showing that it complies with the load and speed requirements of ECE regulations. With certain exemptions (ie tyres for pre-1949 vehicles and for off-road and competition use), from 1 January 1997 new car and light trailer tyres (including 'VR' and 'ZR' radials) must be ECE or EU approved and 'E' or 'e' marked respectively (and from 1 June 1997 for motorcycle tyres). " so from that it looks like i've been sold a non-legal tyre by the MOt station. I shall be on the phone to them in the morning in my best "barrister" voice...

Alright you tyre techno-nerds. Just got my car back from it's annual MOT failure. They fitted a new "budget" tyre. Took a look at it and there is no "E" mark on it. Am i right in saying that unless a tyre has an "E" within a circle, then it is not legal for fitment in the UK ? If so they have stitched me up with a non-EC tyre. So any MOT experts / tyre experts out there pls let me know if it's kosher or not. cheers

I can't remember the pads being noticeably different "cold" to when they'd warmed up. A full race pad will take a while to warm up and certainly woke work well until it's hot, but the Porterfields aren't like that. Why don't you take the wheels off, and pull out the front pads and have a good look at them, (left and right wheels) to see if they look glazed or scored or in any way generally weird. With regards to the disks, the one thing that no disk will like is being used very hard and then stopping the car very soon after. They need air-flow to cool them down a bit after hard use, and this is why people do cool-down laps on track days. I drove round and round for quite a while after my track day to cool the pads / disks as much as possible before parking up, cos red-hot disks will warp if you park up straightaway. This might also explain the discoloration. Is the pedal spongy at all ? If so, bleed the brakes. Is the pedal firm, but just doesn't slow the car as much as you like? This is a coefficient of friction issue betweent the pad and disk. Try fitting new Toyota pads, bed them in, to give you something to compare to. At a meet, try getting someone else to let you have a quick drive in their UK mkiv to see if the brakes feel any different. (Gav ?) I know that with you're reputation this will be as likely as a lottery jackpot but no harm in trying ............ :D If all else fails, I can recommend getting in touch with Darryl Payne (lives near Rugby) to be a general whiz with mkiv stuff, and a very helpful nice chap he is too. he's got all the gear in his garage and he'll take the calipers to bits and sort it all out and pretty much anything else, all for chicken-feed dosh.

good luck with the damn filter change ! Chris W. (or anyone)- if you're still listening in, i've got big oil consumption on my old mk2 Golf. Think it's oil stem seals too. 16yrs old, 114k miles. Question #1 : Is it fine to just leave it, and keep topping up with oil ? Questions #2 : Do those "Stop Smoke" oil additives work ? (asi might need to do something to get it thru the MOT due to smoky exhaust). Questions #3 : Can they fail a car for MOT due to a slightly smoky exhaust ? Or is it only gas emissions that they check for ? sorry for slight hijack. Oil seal related...

Hi Keith Brake History of your motor Those front disks on your car were OE Toyota disks, brand new on the car in February or March this year ! £180 they were. Can't believe you've trashed them already. The front and rear pads are Porterfield R4S pads ("fast road / light race"). The fronts are the very pads that I bought from Paul Whiffin at RAF Bentwaters last year. Gavin had actually bought them, but then i trashed a front set of pads in 2 short sessions and needed front pads just in order to drive home ! (thanks Gav - you saved me that day...) (The Bentwaters track day was on the old front disks.) As Chris said, glazed disks usually happens when you haven't been braking hard *enough*. a few hard stops usually takes the glaze *off*. Earlier this year i got the disks, braided hoses fitted and DOT 5.1 fluid done all at the same time, in addition to the front caliper overhaul kit (from Toyota). All that made a huge difference to the braking of the car. Darryl Payne and I did the whole thing and when we did the overhaul kit, we found that the pistons in the front caliper (especially front right caliper i think) were sticking quite badly. The overhaul kit (piston seals etc.) sorted it completely. I would try a few things : 1) thoroughly bleed the brakes to check that there's no air in there. We had to bleed the brakes twice and i think there may have been just a little bit of air still left. 2) Fit some new stock Toyota pads, and run them in for about 100 miles before braking too hard. Having tried both stock Toyota pads, and Porterfield R4S pads (expensive!) I am of the firm opinion that the stock pads are actually pretty damn good. Certainly Gavin's UK car stopped bloody well on stock pads at RAF Bentwaters, wheareas my R4S pads literally melted to the disk (ask Martin or Gavin - they will tell you ....) 3) if that doesn't have the effect you want, i would take the front calipers off and pop the pistons out (using a compressed air line) and clean them all up. They may be sticking again, though i'd be surprised after only 6 months. The Toyota overhaul kit comprises replacement piston seals and some other bits and pieces. very good value at about £27 incl.VAT., and made a big difference. 4) I've heard Chris Wilson say that the rear calipers can seize a bit on mkiv's that are 5-7 yrs old. If this has happened, then your car would stop, but it would reduce the braking. Overhaul of rear calipers might be a good move. I think Toyota may do a rear brake caliper overhaul kit, in addition to the front caliper overhaul kit mentioned above. If all the above fails, then you're a born racer, last of the Late Brakers, and i advise you to send off an application form to McLaren International immediately. cheers

Lee Hardhead's right on the procedure for setting the rev-limit. But it should have been set already which is a bit odd. I had RLTC with Launch control, and they usually come set with the Launch set to about 4000rpm. When i was at Santa Pod, (ZERO grip) i used the press-and-hold-green button procedure to lower the revs at launch, due to the lack of grip. 4000rpm is good for a nice tarmac road though. At Santa Pod, I lowered it to about 2500rpm. 2 other things that might help (when actually using the LC) : 1) probably has no effect but i'll mention it anyway is that when i used launch control, I engaged 1st gear and THEN pressed and released the green button. (Martin said to do it the other way round). It might make no difference, but try that way : clutch, 1st gear, press and release green button, foot flat on throttle (revs should "shimmer" around your set rev limit) and then clutch in pretty smartish. Obviously if you slip the clutch you'll burn the thing out and that a £500 job to fit a new clutch ! 2) Make sure that when actually using LC (i.e. not when setting the revs) , press AND RELEASE the green button. It won't work if you press-and-hold- the green button for the actual launch.

Adam I fitted a bleed valve to my mkiv myself and it worked great right away. I opened up the valve half a turn, went for a blat, and did that 2 or 3 times until i got the boost level i wanted in 4th or 5th gear. I too used that same piccie that you posted from mkiv.com as a guide but i don't think that the picture is very clear. If Keith has a moment, maybe he could take a digi piccie of the bleed valve in my car (sorry - his car..) and that might help. (in case you got the wrong hose or something). Personally i think bleed valves are great, simple, easy and cheap. And entirely reversible should you want to sell the car or fit an EBC. Also, a lot less "noticeable" than an EBC should you have a prang....

Increasing unsprung weight (i.e. wheels / tyres / brakes / hubs etc) means that there is more weight for the suspension to control when you hit a bump etc. Job of the suspension in a car is to keep all 4 wheels in contact with the road as much as possible. If a wheel weighs a lot it is more weight to be accelerated up and then down again, and the springs and dampers just can't do as good a job of controlling it as it would with a lighter wheel. Also if the additional unsprung weight is contained in the rotating bits ie. wheel and tyre, then it will hurt acceleration and deceleration MORE than the actual additional weight would, if it was just a lump of lead stuck in the car (i think). This is because the wheel/tyre will have a greater rotational moment of inertia which makes it "harder" for the wheel to be spun up (acceleration) and spun down (deceleration). Chris Wilson could probably give a far more eloquent description though. (Earth calling Chris ??)

On the subject of petrol and noticing differences between different brands, one i do not recommend you use (in my humble opinion) is T*TAL Super Unleaded as i used that once in my Golf and it was very very noticeable that the engine was pinking with it wheareas with Optimax it's fine. :( and if anyone from "T*tal" is reading this, then this is my opinion only and so no, i am not being defamatory about your wonderful SUL.

I'd agree with JB here in that, generally, a difference of 0.2secs is far more likely to be just difference between the engines / front tyre grip etc. However, if they are manufacturers figures then,being cynical, the manufacturer will want to actually SELL some of the Lightweight version, and if the performance difference between them is, essentially, nothing, then nobody would buy the lighter version. Hence their official figures show it's worth buying the lighter version. Power to weight difference between the two is just 3% (185bhp/tonne vs. 180 bhp/tonne). Final point - (as Gav said) different weight on car's with identical power / aerodynamics / gearing makes NO difference at all to top speed. Less weight will make the car *get to it's top speed* a little quicker, but ultimately both cars will reach exactly the same top speed.

sidewall i think will only show the *maximum* recommended pressure to run. From a physics point-of-view, for 4 tyres supporting the same total weight (of the car =1.5tonnes) then the larger the tyres are, then the pressures *should* decrease slightly I think. From the equation : Pressure = Force / Area you can see that with the same Force (weight of the car) the pressure *reduces* as you increase the area. Area = contact patchof the tyre with the road. So if the recommended tyre pressures are 36psi for stock tyres (17") then i would maybe run 34 or 35psi on 18" but in the end, it's really down to personal preference. There is the "protect the rims" issue to think about too. Generally i found for stock 17"'s that 36psi was a bit too high, and ran about 34psi rear and 34 -35psi fronts. Wet conditions i would tend to lower the pressures a little. A lot of high-speed running i would tend to increase the pressures a little. try kicking it off at 34psi and increase by 1 psi from there and go for little test drives. I think you'll find it a little jiggly and harsh ride above 35 or 36psi.

Not 100% sure but think it's the manifold. Leon fitted that guage so he will know for sure.

This is one of the best / funniest threads i've read in a while ! Respect to Brad for taking it all in good heart !

Yeah Martin's right. You bolt on the NUR spec and after the stock Toyota exhaust you think "wow that's loud ! and burbly ! and great !!". then you unscrew the little screw, and take out the baffle and then go for the drive and then you think : "Fukc me, i'm a bleeding NASCAR driver". With the baffle out, at 3000rpm and over, full throttle, the NUR spec sounds just demonic. fabulous.

beautiful bit of kit ! almost too good to bolt onto the car. Congrats mate. major major improvement on the stock exhaust. Finally you can actually really hear the engine do its work !

GavtheLad Just stick Optimax (RON98-ish) + Millers Octane Booster (+1RONish) = RON99+ ish in your car and it will be most fine. A full tank of Optimax + Millers Octane booster = £57 ish. So there you are. I just saved you £943 already. cheers

Suprarob just to add to what Phil said, the VFCC is not a boost controller and won't change the max. boost that your car currently develops. but it *allows* other performance mods (like free-flow exhaust, de-cat pipe, electronic boost controller, bleed valve) to work but moving the car's "fuel-cut" level higher. Fuel-cut is set at about 14psi on a mkiv supra and if (as stock) the car detects that turbo boost has reached 14psi, (about 0.9bar or so) then it simply cuts all fuel being injected into the engine which feels like a fairly dramatic bang / event. In effect it's a safeguard to stop the car overboosting. But the mkiv will happily cope with more than 14psi and so installing a £60 VFCC (also known as a fuel-cut defencer / defeater) will raise the level at which fuel-cut happens to about 18psi. you don't want to remove fuel-cut completely. The TRL Performance fuel-cut raises fuel-cut to roughly 18psi or so. So if you install a boost controller or take the cats off and fit a free-flow exhaust like the Blitz NUR spec then the car WILL hit fuel-cut (not nice) unless you fit a VFCC. One final thing - Jap-spec MKiv TT tend to give substantially more boost than UK-specs for certain mods like the exhaust / de-cat. But often they allow too MUCH boost which is defnitely not good. accepted sensible limit for boost on a mkiv is about 17-18psi. UK-spec cars have steel-bladed turbos which are a little tougher than the Jap-spec ceramic-bladed turbos which can suffer from what is known as "pottery failure" if too much boost is used. (ask Barry / JB ...) hope that all makes sense.

I put my UK-spec through MOT with no cats and it *just* failed due to emissions. was marginal though. and you only need to put ONE cat back on to get it through. If you have a "nice" MOT man then you could always explain that you could put the cat back on, but it'll be coming straight back off again afterwards and see what he says.... UK-specs are fine with no cats - no overboost problems at all. you will need a TRL Performance UFCC fitted to allow the car to boost higher than 14psi-ish. Just taking the cats off or just changing the exhaust won't have much effect. you really need to do both to get the big benefit.

Rob you can turn the UK traction control off each time you get in the car (by default it will always be on when you start the engine). OR if you get bored with having to turn it off every time, just pull out the TRAC fuse which is located in the fuse-box near the battery. Inside the black plastic cover is a diagram that tells you which fuse is which. Pull the TRAC fuse, and the traction control is disabled. The little orange light near the rev-counter will now be on permanently. obviously you can always re-enable it by just plugging the fuse back in.

Hypothesise.

yep on the UK-spec (ah, *proper* brakes) you don't need to undo any bolts. You just remove the wire springy-clips which hold the 2 steel pins in place, then pull the pins out, lever the pistons back into the caliper, and then just pull the brake pads out. Admittedly CW was a bit quicker than me ..... first time i did it (pre-Trax 2001 - all 4 pads) i was using brake cleaner, and copper greasing the pins etc.etc. took me ages !!