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300Tdi Defender vs Disco1 Horse Power Tuning Differences

4K views 10 replies 8 participants last post by  KGH 
#1 ·
Does anyone know precisely how to tune to the 300Tdi Disco 1 Horse Power rating of 120 ?

In the same model years, Defenders are spec'd at 111 HP and the UK Discovery's were spec'd at 120 HP.
The Disco's had a Zf4HP22 automatic transmissions while the Defenders had a manual transmission. What exactly did LR do to get the 120 HP which is obviously a safe HP power rating for the 300 and not over taxing the engine ?

Mine is an original 2001 LR repower engine kit made for a 110 but I've got it hooked up to a Zf 4HP22 with a 1.22 TC & 3.54 stock diff's.

I'm not interested in just pouring more fuel in it to go fast & blow clouds of black smoke & high EGT's. I'm interested in precise tuning it to D1 spec's.

Thanks in advance :)
 
#3 ·
The Disco is only rated at 120hp for the version with EDC electronic diesel control, which has an electronic, fly by wire, injection pump, which needs inputs from half a dozen different sensors - that you don't have, and an EDC ECU.. Standard, non EDC Disco's are 111hp, same same. The easy way to increase oomph is to carefully adjust the pump, as here https://www.google.co.uk/url?sa=t&r...gau-vlRjRpFYMKBQg&sig2=i8RgAHH9KYucTRKE_f1rRA
 
#4 · (Edited)
There are also differences in the injection pump of the non-fly-by-wire Disco.
The Disco version has additional linkages which add a secondary enrichment and trim back of fuel depending on the petal position.
The Defender style vehicles don't have the extra linkage that I am aware of.
It is suppose to better coordinate the fueling with the EGR, but doesn't "get in the way" when the EGR is removed.

Like Dave says above, the ECU IP gave more power and is personally something I will always stay away from.
If you can avoid the risk of an ECU failure, than why not do it.

A manual boost controller and fuel adjustment will get you better performance.
Be careful, too much boost will blow the head gasket, which is already a weak point on the TDI engines.
 
#5 ·
A manual boost controller and fuel adjustment will get you better performance.
Be careful, too much boost will blow the head gasket, which is already a weak point on the TDI engines.
I've moved the waste gate blow off hose up to the intake manifold port (same point for my boost gauge) & left the one going to the IP at the turbo. My gauge will now show almost (just shy of) a solid 15psi. My EGT's are running at about a constant 1000°F doing 50mph and peddle to the metal in 3rd.

What do you believe the safe MAX PSI to be ?

This is all brought about because I fought a 20 MPH headwind for about 200 miles & had to stay in 3rd gear doing only 50mph most of the way. I'm looking for more top end power (I assume horse power) NOT pull-a-way from a stop power.
 
#6 ·
If you are 1000 F at sustained full throttle, the fueling is too low. The official limit is 1330 F continuous. You should at least adjust things to be running over 1200.

15 psi is stock boost. IMO, EGT is more important to be concerned about than boost numbers. I'm not really convinced that there is any plausible correlation between head gasket failures and people running higher than stock boost.
 
#7 ·
300 tdi power!

Hi,

Most 300tdi's are tired, compression test your engine first that you are sure it's healthy.

You can change the amount of fuel on your fuelpump, but the biggest difference:

A good working fuel pump and injectors (most are very tired) and VGT(variable) turbo with a larger intercooler with silicone hose kit.
That will make it a complete different engine with all the power you desire.

martin
 
#8 ·
I decided to do some fine tuning to possibly increase my power output.
Took the slack out of my throttle cable & turned the fuel screw up 1/4 turn (I had previously, years ago turned it down about 30 degrees. So a quarter turn will increase the fuel slightly from the factory setting.
I also decided to adjust my valves, something that I have neglected for years to do.
Discovered that the valve caps on the exhaust valves of cyl's 1 & 2 were gone and had a clearance of about >70 thousand's (my other worn caps were right at 58 thousand's). The cap on the intake of the No. 4 cyl was completely worn through and it's remnant was full cracked.

Lot's of forums are stating that there have been many LR style OEM caps of poor quality (soft metal). I decided to buy some hardened caps from Summit Racing made by Air Research Pt.# 4006, they are 80 thousand's thick. Figured after 175K miles my were worn down to the ~60 thousand's I measured on the remainder that were still in place.

With those 3 changes, the engine is much peppier & climbs grades much better., I do get a puff of smoke when the Zf auto-box shifts from 2nd to 3rd, but that's it.
 
#10 ·
It's amazing whaty just a good tune up can do. and adjusting the throttle linkage too.

I had a loan discovery 300Tdi once when an old 110 was in being warranty worked on, this thing was fairly new from the factory (5 speed manual) but was set so lean and low idle that if you booted it up a hill and lifted off it would conk out! I ripped the security seal off the fuelling screw and wound it in a little, the thing flew after that.
 
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