How do you make a TDI rev faster?

Mikkijayne

Veteran Member
Joined
Nov 10, 2007
Location
Devon, UK
TDI
Audi S8
Hi All,

I have read numerous threads on here and elsewhere talking about tuning diesels to make power past the usual ~4500 rpm - some as much as 6000. My problem is that I can't find any info anywhere on how to actually do this. Is it mechanical? Is it fuel quantity or timing? Is it electronic? :confused:

Can anyone put this in black and white for me please? For reference I'm particularly interested in the 1Z / AHU TDI engines.

Thanks, Mikki x
 

mojogoes

Top Post Dawg
Joined
May 1, 2003
Location
england
TDI
mk3 tdi golf
In 4th gear what does your motor rev up too now ,and at what rpm's does it stop pulling and making power.....and where have you heard that a tdi can rev up to 6000rpm.
 

Mikkijayne

Veteran Member
Joined
Nov 10, 2007
Location
Devon, UK
TDI
Audi S8
It runs out of power at about 4000, and will go to about 4500, although I haven't run it in to the limiter. I do have a lift pump but its not hooked up yet, since I don't believe it will make any difference on a stock engine?

I've seen threads on VWDiesel.net talking about 'Giles pumps' going to 6000 on mTDI engines, and I'm sure I've read things on here about going to 5000+. I always thought that the rev limit was determined by the burn rate of the fuel, hence why I'm curious.

Btw Mojogoes - do you have a build thread? I'd love to know how you make 249hp in a mk3 :cool:
 

Drivbiwire

Zehntes Jahr der Veteran
Joined
Oct 13, 1998
Location
Boise, Idaho
TDI
2013 Passat TDI, Newmar Ventana 8.3L ISC 3945, 2016 E250 BT, 2000 Jetta TDI
Revs are limited by the time it takes inject, mix, ignition delay, flash....
the actual burning of the fuel occurs as fast as a gasoline engine. Bottom line is that it's the process of delivering the fuel at the correct interval that takes the time.

DB
 

mojogoes

Top Post Dawg
Joined
May 1, 2003
Location
england
TDI
mk3 tdi golf
Quote....Mikkijayne
Btw Mojogoes - do you have a build thread? I'd love to know how you make 249hp in a mk3

ShuuuuuuuuuuSh its all B/S but don't tell anyone;) .

There the IDI motors and not tdi's what mods have you done plus i take it that this tdi engine in the Corrado.

P.s how long did it take you to do the conversion.
 

Piranha

Veteran Member
Joined
Sep 12, 2003
Location
Malta (Europe)
TDI
golf 2000 Flash Red
A good turbo and tune will get usable power till 5000, 5200 max, for any more you needs loads of work and $$$$$$$$

Mine gets decent power till 5200
 

Mikkijayne

Veteran Member
Joined
Nov 10, 2007
Location
Devon, UK
TDI
Audi S8
Ah so the IDIs can rev faster than the TDI? Why's that?

The engine in the Corrado at the moment is a stock 1Z with worn out rings and terrible blow-by, so I haven't modified it at all. I'm planning to build an AHU to replace it, and I'm gathering info as I go along so that I can build it as best as I can first time round. I'd like at least 200whp, but that will probably depend on what turbo I can find at a sensible price.

The conversion took me two weeks in the winter. If I did it in the summer I could have done it in a few days, but because it got dark so early it took longer than planned.

Mikki x
 

mojogoes

Top Post Dawg
Joined
May 1, 2003
Location
england
TDI
mk3 tdi golf
How long have you had that engine inn......don't get hung up on the fact that an idi will rev higher which is of a petrol mind.......tdi's will produce more power and torque.
 

Mark@MaloneTuning

Vendor , w/Business number
Joined
Sep 24, 2003
Location
Blaine, Washington and Vancouver, British Columbia
TDI
'14 GSW TDI, '11 Golf TDI, '97 Golf Variant Syncro 1.9L TDI, '96 Golf 1.9L ASV TDI, '93 Eurovan Westfalia 1.9L TDI, '09 BMW 335d, '17 BMW 328d
Mikkijayne said:
Ah so the IDIs can rev faster than the TDI? Why is that?
It is said that the IDIs (such as VW 1.9L TD or 1.6L TD) combust faster and more completely than TDIs at high RPM, even with less air consumed and more fuel consumed... at the same smoke level!

There's a bit more technical info here.

The ability to burn fuel completely at high RPM is very important for efficient HP without needing transmission-shattering torque or useless FWD wheelspin (admittedly they look cool, but it doesn't make a car go faster). Ultimately consistent HP wins races - can't argue with the reality of 200ft-lb Hondas running 11's on the 1/4 mile track. However torque's more fun to drive, and is usually more practical in daily driving i.e. highway passes etc.

Here's a graph of my VW 1.6L IDI motor with a 1.9L head.. HP peaked at 5,250 RPM before dropping off due to what felt like a fuel cut-off.



It had a stock cam, stock fuel injectors with no smoke, Giles 9mm pump, a custom GT20 turbo (instant 15 PSI boost at idle - probably comparible to a VNT-17/22), and insufficient intercooling. Giles was going to sponsor a 11mm or 12mm 6,000 RPM pump for this project but the car went off the road.

The engine was in a 1997 Golf and it matched or exceeded the performance of a VR6 of the same vehicle weight, and it was only a 1.6L producing 0% WOT smoke.

There is another similar IDI that went on the road a few weeks ago with more headwork and a large turbo. It was still pulling at 6,000 RPM in 5th gear. 2nd gear was shattered on the 1st test drive. It's running my old 9mm pump although a 6,000 RPM 14mm pump is in the works. It will be very interesting...

FWIW I think my GT20 was one of my restrictions at 5250 RPM - like a VNT-17 or any VNT-17 hybrid it's far too small and EGTs were very high. For good HP a bigger turbo is necessary.

The 1.6L's short 86.5mm (?) stroke and lighter reciprocating parts may have contributed to better revs, along with IDI's theoretical better combustion at high RPM.

The video of a mercedes peeling around, posted here a while back, is an IDI. IIRC it since got a supercharger (now twin-charged) and is smoke free at low RPM. The DIs however still produce impressive power. Is a fully worked DI ultimately better than a comparible fully worked IDI or vice versa? Who knows.. one thing though is that IDIs are already a dying breed (it's been 11 years since TDIs arrived in NA) and DIs are more readily available. The DI market has more $ for businesses and hobbyists to continue R&D in power enhancements. Both the DI and underrated IDI get the same level of support from me!
 
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StingrayRT

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Jul 20, 2005
Location
Slovakia
TDI
AUDI A6 2.7Tdi Avant Quattro
Ohhh I like fairy tails.....especially if it´s a high rpm question on old type tdi engines......

Here is some details to PD engines

1: Electromagnetic injectors has not be under control over 5000rpm - due the high internia load of magnetic disk (duty cycle)
2: Combustion process at this rpm has to be very disharmonic with high portion of exhaust pollutants
3: Injection timing over 5000rpm has to be a serious issue
4: Target rpm for certain engines depend on resonated intake/exhaust tract so if the engine will be designed for high rpm will be ok but OEM
5: Camshaft design is also a key factor to run at high rpm

If someone want to twist tdi like a turbo powered Subaru, Mitsubishi - please stay at gasoline.......piezzo type injectors is a key.....
 

Mikkijayne

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Location
Devon, UK
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Audi S8
Thanks again for the replies :)

I'm not looking for for mad rpms - I'm just curious as to how it's done since I couldn't find the info anywhere, and if its an IDI thing then fair enough.

If a TDI will make power to 5000 ish with a good tune then I'll be happy with that, after all its another 1000 from what I have at the moment! ;) I'm trying to make my car go the same as a chipped Ibiza Fr (PD130 now making 180) and I think 200whp should do that just fine!

Mojogoes - the engine has been in for a couple of months now, and done about 5000 miles in the Corrado. Its about to get mothballed though because of the incessant oil leak and a neverending stream of other Corrado type problems :mad: I'll build up the AHU and then put it back in to service...
 

validius

Lacking in ZDDP
Joined
Oct 9, 2006
Location
Grand Rapids, Michigan
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1997 GTI TDI
My question is why you would want to make this engine revv faster? These engines live on their torque not their revvs. An old 16v gasser is what you want if revvs are desired.
 

mojogoes

Top Post Dawg
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Location
england
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mk3 tdi golf
Mikkijayne said:
Thanks again for the replies :)

I'm not looking for for mad rpms - I'm just curious as to how it's done since I couldn't find the info anywhere, and if its an IDI thing then fair enough.

If a TDI will make power to 5000 ish with a good tune then I'll be happy with that, after all its another 1000 from what I have at the moment! ;) I'm trying to make my car go the same as a chipped Ibiza Fr (PD130 now making 180) and I think 200whp should do that just fine!

Mojogoes - the engine has been in for a couple of months now, and done about 5000 miles in the Corrado. Its about to get mothballed though because of the incessant oil leak and a neverending stream of other Corrado type problems :mad: I'll build up the AHU and then put it back in to service...

Ok i got ya now.......so why not fit a pd150hp from the off or better still a 140hp pd 16v tdi motor for that matter.
 

mojogoes

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Location
england
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mk3 tdi golf
mojogoes said:
Ok i got ya now.......so why not fit a pd150hp from the off or better still a 140hp pd 16v tdi motor for that matter.
You coming from Devon and all.....do you be any chance know DevonMikeyboy( MIKE) with the a4 16v pd :rolleyes: ............OOOOPS
 

Piranha

Veteran Member
Joined
Sep 12, 2003
Location
Malta (Europe)
TDI
golf 2000 Flash Red
Mikkijane,

goe for the pd150 and get a big turbo and work in that 200+ hp on that is relativly easy.

with my setup (AHF 110hp) with some work done, I'm leaving Honda integra's (both JDM and euro) in my smoke, in the 1/4 mile and especially in the road.
5000 rpm is more than enough in diesel, especially when you get so much power so low down.

a PD150 with a decent setup in a (relativly) light corrado will have you go like a rocket
 

Rub87

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Dec 10, 2006
Location
Belgium
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Ibiza '99 90HP
http://nl.youtube.com/watch?v=3GoCxObSrZ8

Did the same thing today.. those 180hp TT's are in fact very slow compored to a tdi with good turbo..

If you want some decent power is has to pull at least to 4500rpm or later..400nm at 4000rpm equals +- 200hp.. if you can hold that too 5000rpm you can do the math..
 

devonmikeyboy

Veteran Member
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Jan 18, 2007
Location
Devon, England
TDI
Audi A3 2.0 PD140 Quattro S-Line
mojogoes said:
You coming from Devon and all.....do you be any chance know DevonMikeyboy( MIKE) with the a4 16v pd :rolleyes: ............OOOOPS
Yeah didn`t you know Steve we are all related and know each other down here. Devoneutopia is my half sister really....:p
 

mojogoes

Top Post Dawg
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england
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mk3 tdi golf
Shut it and take those Welles off!!!........and stop playing that banjo your tea's ready :rolleyes: :D .
 

Mikkijayne

Veteran Member
Joined
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Location
Devon, UK
TDI
Audi S8
Gee I wish I'd never asked now :(

I don't want to rev the thing to 7k! I had a 16V in the Corrado and it was garbage. I put the TDI in because I wanted some torque, which I have now, but it goes flat at 4K which is a shame. Having read that some people could get them to go a bit further I was just curious as to how it's done, and was hoping for a technical explanation.

A PD150 would be lovely, but unlike most people on here I'm not made of money. The best I can afford is a TDI90 so I have to do what I can with that.
 

mojogoes

Top Post Dawg
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Location
england
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mk3 tdi golf
Yeah thats right where all millionaires and billionaires on here...........we have that much money WE DON@T KNOW WHAT TO DO WITH IT..................DO MIKEYBOY!!!

Allard s'accordent un droit de gazole de turbo ne me fait pas rire!! PU....Ne faites pas attention à un turbo de jumeau!
 
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