sempers

Just to clarify what I mean - if the brakes can stop the wheels, what more can they do? The grip of the tires on the road is the limiting factor (unless I'm missing something).

Micra has tiny wheels, ergo, less grip

Or am I missing something? - Lots of folks buy big brakes...

Edited to say that physics proves big brakes can exert more braking force, BUT if the wheels lock at (say)80% force, the extra 20% is no help?

[Edited by sempers - 4/3/2002 1:43:38 PM]

C h a z

Anybody any ideas what the max boost is that can be run in a MY97? The reason I'm asking is that I was reading the old Banzai RR results and I noticed that you guys seemed to be getting more power for fewer mods. Hmmmmm. So I'm thinking can I run more than 16psi.
K&N induction
decat zorst+downpipe
16psi boost held
superchip!

DARREN

Dont go no more than 16 psi without any type of ecu mods when using standard internals!!!!!!
Overboost will occur

Darren

john banks

He has a Superchip though so he will not get fuel cut.

It is a difficult question to answer Charles to just give you a boost to say go away and do it, unfortunately it has to be more complicated.

This is my limited understanding:

I think you have the big turbo (TD05) and smaller injectors, so your bottleneck could well be fuelling and injector pulse width rather more than turbo efficiency? However you also have a smaller intercooler than later models. I am also not sure how much airflow your MAF sensor can measure.

The later models seem more limited by the TD04, but have I believe bigger injectors, intercooler, different MAF and possibly MAP sensor too. So the issues seem more to be intake temperatures and turbo efficiency rather than fuelling.

LEE P

Charlie get summat done with the suspension and brakes! get rid of those pesky two pots! then you can get more out of your car with the handleing!

Lee

RICH WILD

Hi,

If I'm not mistaken, yours is a facelifted MY97 and so will have the bigger intercooler and TD04 (smaller) turbo.

You've got a Superchip so you'll have no fuel cut limiter, but I'd be cautious just cranking your boost up over 16 psi without considering your mixture. What fuel do you use?

I'd get a lambda link or better an EGT gauge to check that you are fuelling correctly before you start faffing with the boost. That's why Superchips have a bad name, because people have had them fitted, wound up the boost without being careful and BANG! new engine.

I run 1.4 bar (~20psi) on a 96 UK but I use Optimax only, NF octane booster (so I'm somewhere over 100 RON), I have a Lambda link and have just bought and EGT and mine has the bigger TD05 Turbo.

Until you get some idea on how rich you are/aren't running I'd stick to 16-17psi.

Also as Lee says quite rightly, running mad boost on 2 pots is crackers. Your performance will be well beyond the car's braking ability. Invest in some decent 4 pots at least. They are always coming up in the For Sale section.

A car with good brakes will be much quicker on the road as you can brake later. My brother's MY97 still has its 2 pots on and when I drove it the other day I was amazed at the difference to my AP 6pots. Nearly broke my nose when I got back in mine and pressed the pedal

Hope this helps

Rich

sempers

Ok, I don't want to hijack the thread, but a "Q" on brakes...

Aside from sharper bite, less pedal effort, I'm assuming the main advantage of the brake upgrades is fade resistance?

Put simply, my 'dodgy standard brakes' are quite capable of locking the wheels (abs aside), so bigger brakes aren't going to stop me any quicker (It does occurr that the ABS may be able to better use them with a sharper bite)

The main prob seems to be that they warm up a little too much... I've been considering looking at cooling them a bit better, rather than necesarily upgrading the brakes.

- Mark.

RICH WILD

Hi Mark,

Bigger brakes WILL stop you a LOT quicker. Sure, they will also be much less prone to fade than other smaller setups but I don't understand what you mean by locking the wheels. That proves nothing.

You can lock the wheels on a 1.0 Micra, but that doesn't mean its brakes are excellent.

A car with AP 6pots will stop a damn site quicker than a car with 2 pots, and that's a fact. The discs are 330mm as opposed to 277mm and the pads are twice the size. The laws of Physics will prove that that means it will stop quicker.

If you are ever in my neck of the woods I'll happily let you have a go in my car so you can feel the difference for yourself.

As I said, my brother has 2 pots on his car and my car stops WAY quicker than his.

Cheers

Rich

nom

Yes.... but at what speed do they lock? At 85 on the motorway when you really need them? I don't think even the standard 4-pots can do that, so I doubt the 2-pots can.
And the 4-pots smell bad enough when that's done to be a reason to change anyway

sempers

Ah, not tried that... Will report back.. later

Then again, why not.. it's not like a scoob develops downforce

Must admit I'm interested in quantifying the improvement. Purely from a point of view of understanding.

Perhaps I ought to bring this up as a thread in wheels, tires and brakes. Sorry!

- Mark.

john banks

Someone also said something about the initial bite being enough to kill a lot of speed before you start to slip?

Certainly even pads, discs and lines/fluid on the Subaru 4 pots make a big difference - it is much easier to lock the wheels, but you can also judge the brakes to the point just before lock up much better and hold it there which seems to help you stop more efficiently.

dowser

I'd say modulation is the key, apart from the obvious anti-fade benefits. You can be *so* precise with a good brake set-up. It allows you more confidence to brake later, with more control, and exit the corner faster. Much faster, you'd be surprised!

As mentioned, on track priorities for going faster are brakes, suspension and then power. But just power is nice on the road

Richard

C h a z

Eibachs, big brakes and a lower front lip are the next things on the shopping list. I just wondered if the superchips 16psi was a conservative figure. I spoke to them today about upping the boost and they were not keen. They said if I took the car down they would show me how to adjust it, but that it was at my own risk.
Heres a thought if I was to connect an air pump to one end of the dawes and a pressure guage to the other, would I be able to set it to an exact 17psi? (depending on the guage of course) Once calibrated I could then put it back on the car.

nom

Err, if Superchips isn't keen, it's probably not a good idea... This is the way to make things pop. Overboost does happen, and things will change when the weather changes... there's a good reason why they leave it at 16psi!

LEE P

Oh dear chaz you seem destined to kill your engine!
i agree if it is set up properly and ya dont medal then fine! but in this case more isnt always better, yep you may get some real fun for a short while but i dont really think you want to fork out for a rebuild/replacement engine?
if you really want to throw money at the car make it worthwhile and get your barkes and suspension sorted!
you will be amazed how much more speed and control you have through the corners, much more grin factor i feel

Lee

john banks

Better to keep the charge nice and cool and have your turbo unstressed, especially with summer coming and if you are going to drive it harder.

During a thrash your boost with a Superchip will creep up probably to 17 PSI - the ECU cannot regulate it like it can with a fuel cut lifter.

I had my first outing ever on the track yesterday, set for 17 PSI, and even though I am a rank beginner, and it was soaking wet, I still managed to thrash it hard enough to be glad I had turned the boost down from my road value. I should be able to tweak my settings a bit more so that the ECU can regulate the boost limit smoothly, but with no regulation it did hit 18 PSI held. I wouldn't want to be any higher.

mutant_matt

Chaz,

handling, handling and handling is the way to go m8 - and then brakes. forget power, the standard Scoob handling is not great and you'll be gobsmacked at how much better you can make it for not a lot of money.

Anyone can go fast in a straight line but cornering is where it's at

Matt