Easiest way to get extra bhp?

[Porny]

So explain to me, whats involved and how much would it cost to remove the cat and what not? And what would i actually end up with at the end of the day? Also! Does anybody know how to learn all these mechanical things? I'd love to do a course over the summer so i actually know my way around an engine instead of looking at it like a bunch of metal bits joined by wires hidden by a big plastic cover.

A deCat pipe (in low grade stainless - as per original exhaust) is about £65 + vat and a couple of pound for a new gasket.

Actually fitting the pipe is quite easy (3 bolts at the turbo end, two where the pipe joins the silencer) - but to get the pipe out you need to remove the gearbox crossmember. This has 4 bolts per side and 'should' simply slide out... usually a bit of gentle bit of help with a hammer is required, sometimes though, you will need to spread the chassis legs slightly to get it out.

As long as you can undo all the bots (including the three at the turbo end) it won't take more than hour to fit... but having it on a ramp makes life easier.

The one thing that everyone seems to have missed...

Get your Defender plugged into some proper diagnostic equipment and have the live data checked - things like low boost pressure, failed MAF sensors, blocked MAP sensors etc etc can make a huge difference to performance! It is also worthwhile having your fuel pressure checked.

On from that... a deCat is a good place to start... but to get any real gain you really want at least a stage 1 remap.

Ian

i still dont get what you mean by middle box. The TD5 has two boxes, one on the downpipe, which is the cat, and one just before the rear axle, which is effectively the backbox.

If your removing both the cat and the backbox then i would think the exhaust would be a bit loud no?

Pre 2002 Td5's (Defender and Discovery) have a main large silencer and one small rear one at the tailpipe.

Post 2002 Td5's (Defender and Discovery) have the CAT in the down pipe, the large centre silencer and one small rear one at the tailpipe.

Ian

What kind of mpg improvements do people get from a re-map?

Depends how you drive it... make use of the extra performance (i.e. drive it like you stole it) and you WILL use more fuel.

However, drive it in the same manor as you normally do, but make use of the extra torque (you will change gear less!) and you should see an improvement.

One of my customers keeps a log of every single drop of diesel that he puts in his Defender... since having a stage 2 remap he gets 4mpg better on a run (same journey)

ian

[Aragorn]

tbh the best way to learn is to just get stuck in and do it.

I learned that way with my first car armed with a haynes manual and a socket set, start small and then slowly build up to the larger tasks. Also means you can build your tool collection as you go, and being a member on forums liek this helps as you can ask for advice etc as you go.

To remove the cat you need to get a new downpipe that doesnt have a cat in it, and swap this over. Alternatively you could get a section of suitable pipe, and cut the cat out of your existing downpipe and replace it with a length of pipe.

Its a simple enough job to do, and you wont have any MOT issues as diesels dont require a cat for the MOT.

The DIY approach is probably going to be cheaper, but you'd really need to be able to weld to do it cheaply. Jetex do a range of custom exhaust parts which would no doubt have a suitable section of pipe, but the sleeve clamps to join the sections are a little tricky to find, and are relatively pricey.

http://www.mm-4x4.com/defender--discovery-...pipe-3006-p.asp

That would do the job nicely.

They also sell a pipe to replace the other silencer, which from the discussion with reb would seem to also help free up the performance a bit too

If it was me, i'd do the Decat and EGR replacement first as they're both very cheap to do and will make a noticeable difference, and will also help you get more from a remap when you get to that point, and i'd probably do the other box replacement too while your there.

Ah cheers for clearing that up porny, I didnt realise early TD5's didn't have a cat, especially seen as late 300TDi's do!

[yorkshire90]

I've had my TD5 since 2004 and to date this is my initial route (in order) for getting more grunt from my Td5 was the following:

1) K&N filter

2) Mid box stainless steel replacement pipe

3) EGR removed

At this point the TD5 was a tad more spritely. Greater clean air sucked into the combustion chamber due to the EGR removal and K&N. More mid range pull due to the replacement pipe.

4) Stage 1 remap

5) Stage 2 (Intercooler + silicon hoses) as I later leaned that with a stage 1 remap the Exhaust gases increase in temp. Adding the intercooler reduces them and gains more grunt. Win win purchase

6) SOLD the performance parts when I thought I was going to sell the 90.....

7) PURCHASED new Stage 2 gear from Porny at IRB and Im back to square 1

[C18RCH]

Would removing the cat not increase emmissions and therfore cause an MoT failure?

[Porny]

Would removing the cat not increase emmissions and therfore cause an MoT failure?

On a Petrol vehicle yes.... on a diesel no.

The current 2008 MOT system for Diesel (i.e. compression ignition) vehicles only requires an Opacity test, (i.e. smoke) and not an actual emissions test (including NOx) as per petrol (spark ignition engine).

The EGR system and the catalytic converter for that matter do not actively affect smoke…. This differs from a diesel particulate filter (which is also exempt from testing at the current time). The only requirement is that the max smoke value for a turbo charged diesel is a mean (of the last 3 smoke tests) not exceeding 3.00m-1. For an initial 'fast pass' the smoke value must be below 1.50m-1.

In simple terms.... the only reason a modern diesel have CATs and EGR (along with other things) is to enable a manufacturer to meet the current EU legislation (for example EU4/5), but once a vehicle model has been type approved, and sold to the customer... the customer is technically free to do what they like regarding emissions, as long as they meet the requirements of their country, which in the UK is just the MOT test.

Ian

[flatback90]

IRB (porny) does a switchable map for td5's so your dad can leave it as it is and when you want to got tiddle off corsa's you switch it on. its even switchable on the fly. BTW i'm 37 and love booting out of junctions in mine just to see the look on peoples faces!!!

[Anderzander]

Thanks Ian!

That's a big help.

[SteveG]

Would removing the cat not increase emmissions and therfore cause an MoT failure?

Just to add to Porny's post, my TD5 90 was MOT tested on Tuesday and results were a Fast Pass with a corrected reading of 0.79 l/m and also a surprised MOT tester when he took it out for the brake test

My 90 has ....

EGR removed (IRB Dev)

Exhaust - decat SS front section, Straight through SS centre section, and standard LR rear section

Stage 1 remap (IRB Dev)

Cheers

Steve

[Anderzander]

How's the noise Steve?

I have the pre cat td5 and am thinking of a straight through centre section - prior to a map. I want the smoother revs and the extra space underneath but I don't really want to increase the noise or have a really different tone....

[SteveG]

but I don't really want to increase the noise or have a really different tone....

It increases the noise, more boomy (great at describing things me ) and you'll hear the turbo whistle more.

It's fine to live with but it's louder. Remap will add a bit more noise too.

Steve

[bigbeast]

so with my defender being a '99 i now know i do not need the dec-cat pipe as i dont have one save myself some pennies

will be going for the EGR

porny you have a PM cheers

[RedLineMike]

Hmmmm

200bhp TD5

that aint gonna happen from a remap & filter n exhaust

[Aragorn]

erm it pretty much is...

might need a cooler to get there, and you might be talking 190-195 rather than 200, but its close enough surely?

[discomikey]

Classy - did that come with a dyno sheet or is it just a classic internet guess?

it came with a dyno sheet B)

i know its a bit O/T, but could someone please PM me with tha answer,

but it wouldnt start the other day, it just kept turning over, and aparently it spluttered a bit the other day.

when i got in it to have a go at starting it, it turned over, i felt like it wanted to go, but wasnt properly firing enough to get fully goin, so i put my foot on he accelerator a bit and hey presto, then i turned it off and restarted it and it was fine.

help appreciated.

mikey

I have a 200tdi 110. It has two silencers and no cat. removing the front silencer is meant to increase power. I assumed perhaps wrongly that the TD5 had two silencers - perhaps the TD5 110 does in which case this is applicable. The TD5 90 sounds like it doesn;t, so removing it is not an option!

it might not have 2 silencers, but a TD5, 300 or 200TDI will all pass their MOT with no silencers whatsoever, in theory, (dont quote me on that) this is because the turbo actually acts as a silencer, and makes it just quiet enough to pass the MOT, i have witnessed a TD5 passing with no boxes or cats but it may vary from garage to garage due to small differences in equipment calibration. and you can hear the turbo really loud, and it sounds like a v8 when you rev the bolloc*s off it which makes me giggle like a 16 year old boy (partly because i am )

mikey

[RedLineMike]

erm it pretty much is...

might need a cooler to get there, and you might be talking 190-195 rather than 200, but its close enough surely?

Hmmmmm

have dynoed approx dozen td5s in various guises shapes & forms inc several twisted 200+ conversions & have yet to see one make more than 185 ATF, even porny has proved that you require a turbo upgrade to start getting into the 190's, never mind the 200's

[Aragorn]

i'm sure there was a thread on here a while back with porny taking a TD5 that had been tuned to "200+" and dynoing it, then comparing each mod before doing a proper remap himself, and i'm sure his final power figure was over 190hp...

[Porny]

i'm sure there was a thread on here a while back with porny taking a TD5 that had been tuned to "200+" and dynoing it, then comparing each mod before doing a proper remap himself, and i'm sure his final power figure was over 190hp...

These are the threads:

http://forums.lr4x4.com/index.php?showtopi...t=0#entry235646

And http://forums.lr4x4.com/index.php?showtopi...t=0#entry235646, and then http://forums.lr4x4.com/index.php?showtopic=40056&hl=

Unfortunately it's probably not worth reading past the first few posts as it just turns into a slanging match.

However...

Stage 1 - you looking at approx 150bhp

Stage 2 - approx. 175 - 180 bhp

Stage 3 - approx. 190 - 198 bhp

Stage3 (with a variable geometry turbo) and another mapping session - 208bhp.

Torque is the more important figure, but I can't remember all the values off the top of my head.

I have graphs/figures of all of the above on a proper calibrated dyno.

Ian

[Aragorn]

Ah cheers for clarifying that

What exactly does each stage consist of?

I think your saying that stage 3 without the VNT will produce between 190 and 198hp, so what exactly does that consist of?

Cheers!

[Porny]

Ah cheers for clarifying that

What exactly does each stage consist of?

I think your saying that stage 3 without the VNT will produce between 190 and 198hp, so what exactly does that consist of?

Cheers!

Stage 1 is just a remap

Stage 2 is a full size replacement intercooler, a matched remap to the intercooler and a boost box (to prevent overboost)

Stage 3 consists of remap to suit new mods, road spec intercooler, boost box and a hybrid (none variable) turbocharger.

Stage 2 is about as far as you can go if you want to keep the standard turbo (set to 18psi).

And then ideally an EGR removal kit, DeCat is post 2002, air filter etc etc.

Ian

[Philip Tonkin]

Ah cheers for clarifying that

What exactly does each stage consist of?

I think your saying that stage 3 without the VNT will produce between 190 and 198hp, so what exactly does that consist of?

Cheers!

I believe all stage 3 includes over the Stage 2 is a hybrid turbo.

[Aragorn]

Aaaah, hybrid but not VNT. Got ya!

So basically the stock blower is flat out at 185hp, and anyone claiming more is lying effectively?

What you need now, is LPG or LPG & Nitrous.

See if you can wring 250 or 300hp out of it

[Philip Tonkin]

What about adding cryogenic intercooler sprayers..

Apparently good for 60% increase in cooler efficiency...

[Aragorn]

nitrous is a more effective use of the gas tbh...

it has a similar cooling effect on the intake charge, and adds more oxygen to the party.

But unless you can somehow map the engine to add more derv when on the gas, you really need to inject an alternative fuel like LPG alongside it, then keep a VERY close eye on the combustion temps!

[bpman]

my 2p worth...

- if you are running a 200 ish BHP td5, consider upgrades for the brakes, springs, Anti-Roll bars first.

- why not just buy a caterham?

- get a sticker for the back door of your defender "You can go fast, I can go anywhere"

[Aragorn]

Plenty folk are running V8 defenders which make at least 190-200hp and have a much wider power band, yet i dont see people asking these folk to go buy a caterham...

200hp in a defender isnt fast. Its no faster than a mid range family saloon (something like a 1.8 mondeo), and certainly wouldnt be described as sporty...

The brakes and suspension upgrades are something to think about, but i dont think you need to go too mad. The brakes are capable of pulling up a fully loaded 110 with a 3 tonne trailer on the back, so a little 90 shouldnt be a problem for them. Ok, take it down a back road with your foot welded to the floor and you might well cook them, but you just need to realise your NOT driving a caterham, your driving a 200hp 4x4 with beam axles. I'll be fitting vented 110 disks on mine, and perhaps some good pads, but i'm not going to go wild on it. I dont think it will be safe to push the truck hard enough to cook them, so unless i'm proved wrong once i get it on the road then i'll be sticking with the stock calipers etc.