yhe chod

will i get any problems or risk blowing up /damging my engine if i fit a cat free open mouth downpipe to my ppp my99 uk scoob? how will i know/how can i tell if i get overboost .and will overboost kill the engine.

Leviathan

somone will post who knows more about it than me but i have heard that these can cause boost spikes and possible lean running on some cars without re-maping to compensate.

Peanuts

iTrader: (15)

on MY99 uk h&s downpipe is mucho

Kane

will be getting mine done shortly...I am getting it priced for the following:-

1.Downpipe
2.Remap following
3.Rolling road

Any overboosting should be sorted out following installation. My Bro had his replaced and he got overboost - put in and they sorted it out..Think you just get fuel cut due to the overboost. If you get a downpipe fitted why not get it mapped after - no harm in checking..may cost a little more but its worth it to keep confidence in the car.

jameswrx

iTrader: (4)

Get a decent boost gauge, and learn how to read it. Then monitor

Kane

Boost gauge - assume nowadays most people have boost gauges fitted - sorry m8

nom

A cat-free DP is likely to reduce stress on the engine (the cat seriously bungs things up and causes a lot of heat), as long as this overboosting thing everyone is mentioning is kept an eye on. A little ocassional overboost should cause no problems, but over time, if consistent, it will cause problems.
Boost gauge - good idea

yhe chod

ive got the prodrive performance pack ecu [uk99] that came with the package-who can re-map this does anyone know

greasemonkey

Any EcuTeK mapper should be able to remap the '99 PPP ECU, so that's no big issue.

There is a risk of spiking post-decat downpipe in your scenario as IIRC part of the PPP installation involves replacing the standard 1.2mm restrictor with a smaller one to promote earlier boost rise. This together with a full decat is a known problem area.

As has been said above, if you have an accurate, fast responding boost gauge and know how to read it, you should be able to spot spiking immediately. If you add a KnockLink and AFR meter though, you'll have a crucial extra level of insurance.

Jess

Hi,

New to this and have been thinking of putting a full de-cat system on my standard MY99. From reading this thread do I need to get it re-mapped (can you re-map the std ecu) once fitted???

greasemonkey

Yes, the 99/00 ECU's can be remapped by EcuTeK, but if you have kept the standard induction assembly in place, you probably won't need a remap to sort a decat downpipe, it may well be fine as it is.

If you do get mild spiking, as mentioned above, the most practical way to combat it is simply replacing the standard actuator restrictor with one with a slightly larger bore. You can make these restrictors yourself for a few pence each provided you have access to a few simple tools.

The important thing is to have an accurate boost gauge fitted before you change the downpipe, so you can get an idea of how the boost is supposed to look, and thus you'll instantly be able to see if it's changed.

Jess

Thanks Greasemonkey.

Any suggestions on Boost Gauge to get?

yhe chod

whats a good electronic readout boost gauge anyone and how much fitted? greasemonkey-can i just change the actuater ristricter on my pppuk99 and avoid overboost or do i really need a re-map. also what is a knocklink and how much does that cost fitted? why will a afr meter help?

[Edited by yhe chod - 9/23/2003 8:41:25 PM]

StickyMicky

a boost controller will sort out any boost spikes
you can pick up a second hand dawse device from between £20 / £35

or you can get copycat type controllers for about £25 brand new

greasemonkey

Whoa, few questions in one post there!

Firstly, the most useful boost gauges are regular "analog" needle display ones (even though many are actually digitally driven nowadays!). They're easier to read at a glance and show spiking much more obviously than the digital readout variety. There are a few good ones so difficult to recommend just one. Only thing to say is that I use a Blitz compact digital and it works very well.

You probably can cure any spiking by playing with the restrictor bore without the need for a remap. Key would be to get the gauge first and get an idea of how your car is supposed to build and attain boost, change the downpipe, then, if necessary, put larger restrictors in to cure any transients.

A KnockLink detects knock, aka detonation. This is when the fuel/air mixture in the cylinders ignites spontaneously - as a result of high charge/cylinder temps, insufficient octane rating petrol, overboost as well as other causes. It's a potentially engine destroying problem and while your engine has a knock sensor already feeding the ECU, the KnockLink's separate sensor is more sensitive - and it'll give you direct warning that all is not well by flashing a big red LED, enabling you to back off and find the cause of the problem.

An AFR (air to fuel ratio) meter will give you confirmation that your ECU is supplying the correct amount of fuel to the engine, so again its little lights will work hand in hand with the KnockLink to let you know that the engine is working within safe parameters. It can also give you advance warning of faults like a failing MAF sensor - which could cause serious damage to the engine if it went bad without you knowing.

There are a few places to get boost gauges, while you can get the KnockLink here and the Dawes AFR meter here.

If you're reasonably okay under the bonnet, you should be able to fit all these yourself without any trouble, but if not, have a word with the people concerned as to what their fitting charges would be.