2260 first experience....

[faboka vrs]

Just wound out the stopscrew a half turn so the turbo is boosting better lower down.

Jas, you done any basic settings - group 11 tests? Would have thought Darkside would have set the turbo up spot on before they sent it.

Steve, be interesting to see how yours boosts.

[SKYHAWK]

Jas, you done any basic settings - group 11 tests? Would have thought Darkside would have set the turbo up spot on before they sent it.

Steve, be interesting to see how yours boosts.

 

just gathering a few more toys before it comes to you for some magic!

[coskev]

If you want to be able to use the GTB power a diff really is a must, logging in Joe's last night on a damp private test road and it was wheel spinning in 4th gear at 80mph

[silky16v]

Guys who are considering it - take it from me, you definitely need to go down this route!! It really is awesome   Steve you won't be disappointed. it knocks the socks off the hybrids. Drives more like a turbo petrol motor now. Obviously half of this is down to John's awesome mapping too - and he's not even finished with it!

 

Southy you need to get it sorted lad

 

 

 

 

All misunderstandings aside Silky  , Xman said that I needed to fit a 2.75" downpipe. However, the flange provided is only 2.5" in diameter! Plus as Kev said, the turbo outlet is also 2.5". So as long as there's no restrictions in the pipework, 2.5" will be fine.

 

As for 3", the guy at Longlife exhausts (also called Kev!) showed me that a 3" pipe physically won't fit because of the downpipe's stud pattern on the turbo.

 

I definitely agree that the 2260 is the way to go though, having driven both Dan and Kev's 1756's. Unless of course you definitely don't want any more than 240bhp - then there's sort of no point.

 

 

 

I need a diff now! Steve I'm very envious of your Quaife right about now!!

 

 

if you look at a DS downpipe it is stepped at the flange

 

hard to make out in this photo but you can just see it tappers down to the flange to allow fitment, the reason behind the 3" DP is to allow the latest area of expansion for the hottest exhaust gases

 

some will agree its needed some will not, but my experience i noticed from changing from the 2.5" DP on the 1756 to the 3" on the 2260 is that it's quieter on boost and doesn't sound like the exhaust is struggling due to restriction & be far more free reving

 

When i was on the hybrid the Miltek DP is only 2" at the flange and 2.5" after the flexi joint and that use to howl like hell on boost and doesn't rev anywhere near as much

 

I know Kev is saying that it only needs to be the same size as the exhaust outlet size, but you only have to look at Cossie & Evo downpipes compared to there exhaust wheel size and you will see they all use 3" DP (after market) don't know the finer details but its all to do with the exhaust gas expansion right after the turbo

 

don't want to start a huge debate/slagging match i'm sure a 2.5" DP is fine if this is what you have already, as mine came with a DS 3" DP that obviously what i fitted, and my feeling are its quieter and less restrictive than the 2.5" DP

 

i also think that JK automotive supply 3" DP for not a lot of £££ http://www.ebay.co.uk/itm/JK-AUTOMOTIVE-GTB2260VK-MANIFOLD-KIT-1-9-8v-TDI-ENGINES-/171504822803 he's offering this kit for £700 on FB which tbh is bargin

 

 

 

Oh and LSD is a must, mine is utterly pointless in the wet or damp road

[Cooke]

All this talk about turbos and exhaust is making me want to spend money i was happy with the standared car till this thread

[DanHam]

Seatch DTM tuning on Facebook. He does the manifold and down pipe for £600. Can't believe I almost paid over £2000 for the full kit.

[Southy]

I could have it done within a weekend if I didn't need/want the selector forks strengthened, this is gonna make more work and make things a bit harder to get it all sorted in a short time span....think I may take a day off work and drop box on the ramp at work and then strip and sort it out and fit diff and flywheel etc

[SKYHAWK]

Well, I picked the motor up tonight from having its custom made side-exit Longlife exhaust done (updates to follow soon enough in my project thread). I was a bit nervous about driving it at first due to having just fitted the turbo amongst other things. However, I'd double and triple checked for leaks (ask Kev!) just to be sure we were good to go.

 

For now, Kev made a guess at the actuator position based on his experiences with the 1756. He's definitely not far off though, as when I put my foot down....  holy **** the car has been completely transformed!!! Genuinely, I cannot believe the difference between this and the PD150 hybrid. It pulls and pulls and pulls - just doesn't stop!

 

The car is also only currently running a base map for the 2260 and 4 bar map sensor, so didn't want to go too crazy just yet. So the map will be starting to get tweaked by John this weekend. The map that's currently on there is so much more drivable than my old one though, as it's massively smooth and progressive... ending up in just savagery!

 

I must point out that this was also on the low boost map that John sent me....   The mind boggles as to what it's going to be like when it's running even more boost with a more refined map

 

One extremely happy person here

 

So if anyone is on the fence about upgrading to a GTB series turbo....  DO IT!!!

pictures of side exit exhaust m8

[alex_e3]

some will agree its needed some will not, but my experience i noticed from changing from the 2.5" DP on the 1756 to the 3" on the 2260 is that it's quieter on boost and doesn't sound like the exhaust is struggling due to restriction & be far more free reving

 

When i was on the hybrid the Miltek DP is only 2" at the flange and 2.5" after the flexi joint and that use to howl like hell on boost and doesn't rev anywhere near as much

 

I know Kev is saying that it only needs to be the same size as the exhaust outlet size, but you only have to look at Cossie & Evo downpipes compared to there exhaust wheel size and you will see they all use 3" DP (after market) don't know the finer details but its all to do with the exhaust gas expansion right after the turbo

 

don't want to start a huge debate/slagging match i'm sure a 2.5" DP is fine if this is what you have already, as mine came with a DS 3" DP that obviously what i fitted, and my feeling are its quieter and less restrictive than the 2.5" DP

 

 

I see your point, and agreed that a big debate on it is pointless, as mine's been done and I'm happy enough with it! Interesting the point about the noise though, as Kev at Longlife was pretty clear when we were talking about all this, and he said that the 3" will actually make MORE noise than the 2.5"...   I'm really happy with mine anyway, and it doesn't particularly sound noisy from that area - although obviously I don't have a 3" on this setup to compare to. It would definitely be very interesting to see someone run 2.5" and then 3" on the same setup for some concrete proof either way!...

 

 

 

pictures of side exit exhaust m8

 

I didn't get any when it was on the ramp due to having my phone nicked the previous weekend (and forgot to take my 'normal' camera!). I'll get some shots of it when I get it raised up this weekend to set the actuator properly. Car is too filthy to dare post up a shot of the tailpipe for now though! Hoping that the weather will clear and allow me to remove the soot from the boot for the last time

[sepulchrave]

my feeling are its quieter and less restrictive than the 2.5" DP

 

Fortunately engineering isn't done on 'feelings', the most restrictive part of the exhaust system is....

 

THE TURBO!

 

....ta da.

 

Exhaust gas exiting the turbine is actually cooler and slower due to the turbo having removed so much of the energy from it. As long as a system isn't restrictive then going bigger will make bugger all difference, it still won't be restrictive!

 

Fools and their money are easily parted and I can categorically assure you that there are some very serious fools in the YB/C20LET and Evo/Scooby tuning camps.

[faboka vrs]

So I've been having a play with some figures. Looking at air volume at the intake and then air volume at the exhaust taking into account fuel volume and exhaust temp increases. I'm assuming EGT pre turbo at WOT is around 720C (thanks Kev) and then assuming a 20% reduction post turbo as the turbo will take some of this heat away.

 

All estimates.

 

Stock exhaust is 2.25inch. Not taking into account pipe thickness.

170bhp = Mach 0.23

200bhp = Mach 0.26

235bhp = Mach 0.28

250bhp = Mach 0.3

275bhp = Mach 0.33

300bhp = Mach 0.37

 

2.5inch. Not taking into account pipe thickness.

170bhp = Mach 0.18

200bhp = Mach 0.2

235bhp = Mach 0.23

250bhp = Mach 0.24

275bhp = Mach 0.27

300bhp = Mach 0.3

 

3 inch. Not taking into account pipe thickness.

170bhp = Mach 0.12

200bhp = Mach 0.14

235bhp = Mach 0.16

250bhp = Mach 0.17

275bhp = Mach 0.19

300bhp = Mach 0.21

 

So going from that a 2.5 inch exhaust at 250-275bhp has similar pipe velocity to the stock exhaust at 170-200bhp. A 3 inch pipe at 300bhp would have a similar pipe velocity to a standard system at 170bhp.

[devonutopia]

^^^ I like that post.

 

It makes it seem a good idea my system is 3" - I assume the calcs likely exclude things that might get in the way like a cat or other backbox/es?

 

Mine only has one backbox but it's a hefty one, but does a good job of taking the noise out the system, whilst still being 3" in and 3" out.

 

[faboka vrs]

Correct doesn't take into account cats, silences, bends, pipe thickness.

But my point is it shows a value for a stock system at 200bhp which we all know is perfectly fine. So we can use that as a base for the larger pipes.

[SKYHAWK]

my vxr is 3" straight through no cats or silencer mated to a tubular manifold and a garrett gt30

[sepulchrave]

To expand on Fabokas velocity calculations and because some of you might be interested in a more complete understanding of what's involved:

 

For a 1.9 Litre VW PD engine developing peak power at 4500rpm using 2 bar absolute pressure with an inlet air temperature of 20C and a pre-turbo exhaust temperature of 720C:

 

1.9L x 4500rpm x 2bar x 0.5 for the four stroke cycle = 8550 L/min

 

Add fuel at approximately stoichiometric ratio:

 

8550 x 1.08 = 9234 L/min

 

Apply the perfect gas laws which state expansion is proportional to temperature:

 

Convert to degrees Rankine:

 

(20C + 273.15) x 9/5 = 527.67R

(720C + 273.15) x 9/5 = 1787.67R

 

Gives us the exhaust gas expansion rate:

 

1787.67R / 527.67R = 3.39

 

Exhaust flow exiting cylinders:

 

9234 L/min x 3.39 = 31303 L/min

 

Exhaust flow exiting turbo after 20% energy removed by turbo:

 

31283 L/min x 80% = 25026 L/min

 

Converted to Cubic feet per minute:

 

25026 L/min / 28.3 = 884 CFM net exhaust flow.

 

The important thing to note here is the expansion ratio, because EGT in a turbo diesel is so much lower than a turbo petrol there is far less expansion, therefore a larger diameter exhaust pipe simply isn't needed, this is why the standard 2.25" system works so well and why 2.5" is plenty because the EGT isn't any higher and the peak rpm hasn't been raised like in a tuned turbo petrol engine where the flame propagation is so much faster and wilder cams and bigger turbos can be used.

 

This is also why we talk about torque rather than power when tuning diesels because we can't raise the rpm range like we can with petrols.

 

Please shout if there any errors in my calculations, I've rounded where appropriate.

[Jrjg]

If you want to be able to use the GTB power a diff really is a must, logging in Joe's last night on a damp private test road and it was wheel spinning in 4th gear at 80mph

And I thought wheel spinning in third at about thirty miles an hour in the wet was bad...

JRJG

[devonutopia]

Don't think I have ever had 4th gear wheelspin, in any conditions.  3rd gear in very wet perhaps.  I guess this must be because the diff does such a good job.

[vRS Joe]

Yes I could do with a diff, but they're just a bit too pricey! I would have preferred to log in 3rd gear, but it wouldn't have gripped at all. I don't think Avon ZZ3's are the best tyres for damp roads!

[devonutopia]

I admit I won't go out logging unless its dry.  Taking my car up to the sort of speeds 3rd gear maxes out at (about 90 in my car km/h ) I want to have the safest possible driving conditions.

[silky16v]

4th gear wheel spin in the wet all the way to limiter, just gotta live with it i suppose until i fit a diff

[andypandypoos]

Don't think I have ever had 4th gear wheelspin, in any conditions.  3rd gear in very wet perhaps.  I guess this must be because the diff does such a good job.

 

Ben complained of fourth gear wheelspin in my Ibiza the other day, on a damp road. it's got a peloquin diff fitted. new tyres are on order

[DanHam]

This car with 2260 goes well, and the map isn't even finalised yet!!

Let's just say a young lad with his girlfriend in his corsa vxr must have been embarrassed

[alex_e3]

Don't know what you're going on about Dan....

[SKYHAWK]

This car with 2260 goes well, and the map isn't even finalised yet!!

Let's just say a young lad with his girlfriend in his corsa vxr must have been embarrassed

i smoke standard corsa vxr's with my hybrid

[DanHam]

i smoke standard corsa vxr's with my hybrid

Cool. We don't know if this one was modified or not. The corsa had a head start and still passed him with ease.