Con rod specs for Turbo Technics TT
Discussion
I have a Turbo Technics Twin Turbo kit for a M103 (Mercedes) engine.
I'd like to have it fitted to my G, but despite enquiries to Turbo Technics in Northampton, I cannot get the specs. I know I can resolve the problem electronically, but I would prefer to do it mechanically.
Originally when these were fitted (mainly by Hughes of Beaconsfield) and the con rods were sent back to Turbo Technics for exchange/adaption.
If anyone knows the specs I'd be very grateful.
Thanks.
I'd like to have it fitted to my G, but despite enquiries to Turbo Technics in Northampton, I cannot get the specs. I know I can resolve the problem electronically, but I would prefer to do it mechanically.
Originally when these were fitted (mainly by Hughes of Beaconsfield) and the con rods were sent back to Turbo Technics for exchange/adaption.
If anyone knows the specs I'd be very grateful.
Thanks.
DVandrews said:
On other TT conversions the rods have been shortened to lower the CR, this was acheived by re machining the big end eye higher up the rod. Whether this is true for your engine I don't know...
Dave
Yes, that is what is done and I can easily get someone to do it, problem is, I can't establish the specs.Dave
stevieturbo said:
DVandrews said:
On other TT conversions the rods have been shortened to lower the CR, this was acheived by re machining the big end eye higher up the rod. Whether this is true for your engine I don't know...
Dave
Seems a totally extreme way of lowering CR !!Dave
stevieturbo said:
IanA2 said:
Why so? It was the way the kit designed and approved by Mercedes. If you know another mechanical way I'd be grateful for some pointers.
The same way it is lowered normally..Via dish in pistons, new pistons, cylinder head chamber size, thicker gasket etc etc
But again the problem is the specs. Also, the gasket might be a problem. Any ideas?
IanA2 said:
Yes, that is what is done and I can easily get someone to do it, problem is, I can't establish the specs.
Have you a rod and piston to hand? If so you could measure the offset of the journal or perhaps how far below tdc the piston sits at the top of it's stroke taking care to factor in where the piston would sit on an unmodified engine. IanA2 said:
Yes I know of that alternative. Although it's not the way the kit was designed it would probably work.
But again the problem is the specs. Also, the gasket might be a problem. Any ideas?
Googling suggests the M103 is around 9.2:1 CR ?But again the problem is the specs. Also, the gasket might be a problem. Any ideas?
Even without an intercooler, this is quite low enough for some boost without any concerns. With a decent intercooler, you should be able to use even 10-15psi without any real problems.
Unless you have no ability at all to control ignition timing, or have to use very poor fuel quality, I wouldnt want to be lowering the CR much more in the first place
What CR did TT lower theirs to ?
I'd sooner look to better fuel/spark control, than to pulling engines apart. It will offer better performance all round...and be easier.
IanA2 said:
I have a Turbo Technics Twin Turbo kit for a M103 (Mercedes) engine.
I'd like to have it fitted to my G, but despite enquiries to Turbo Technics in Northampton, I cannot get the specs. I know I can resolve the problem electronically, but I would prefer to do it mechanically.
Originally when these were fitted (mainly by Hughes of Beaconsfield) and the con rods were sent back to Turbo Technics for exchange/adaption.
If anyone knows the specs I'd be very grateful.
Thanks.
To be honest who cares what the specs were when you can decide that for yourself and calculate the required machining very easily. TT were notorious for being ridiculously overcautious on CR for their turbo conversions to the detriment of turbo lag and low rpm driveability.I'd like to have it fitted to my G, but despite enquiries to Turbo Technics in Northampton, I cannot get the specs. I know I can resolve the problem electronically, but I would prefer to do it mechanically.
Originally when these were fitted (mainly by Hughes of Beaconsfield) and the con rods were sent back to Turbo Technics for exchange/adaption.
If anyone knows the specs I'd be very grateful.
Thanks.
If your engine is the 88.5mm bore, 80.2mm stroke one that Google suggests then the calculations are as follows.
Stock - 9.2:1
Rod shortened 0.50mm - 8.80:1
Rod shortened 0.75mm - 8.62:1
Rod shortened 1.00mm - 8.44:1
Rod shortened 1.25mm - 8.27:1
1mm off should be fine for anything up to a bar of boost with good mapping. Simples
Many thanks guys. Lots of v helpful ideas/suggestions.
Maybe I've fixated on a mechanical solution a) because that's how it was designed & b) because it's an old (1991) engine (although only covered 87K).
I do have an electronic solution that will work (it's proven) so maybe that is the way to go. I don't know.
Any idea as to where I might get the thicker gasket made up?
I don't know if TT were cautious as they were working with MB looking over their shoulders.
Maybe I've fixated on a mechanical solution a) because that's how it was designed & b) because it's an old (1991) engine (although only covered 87K).
I do have an electronic solution that will work (it's proven) so maybe that is the way to go. I don't know.
Any idea as to where I might get the thicker gasket made up?
I don't know if TT were cautious as they were working with MB looking over their shoulders.
IanA2 said:
Many thanks guys. Lots of v helpful ideas/suggestions.
Maybe I've fixated on a mechanical solution a) because that's how it was designed & b) because it's an old (1991) engine (although only covered 87K).
I do have an electronic solution that will work (it's proven) so maybe that is the way to go. I don't know.
Any idea as to where I might get the thicker gasket made up?
I don't know if TT were cautious as they were working with MB looking over their shoulders.
Times have moved on, electronic tuning has moved on. The standard CR is low enough for a very modest amount of boost without touching the engine at all. So really that would be the best option, rather than choosing to be bound by something designed 20+ years ago and sticking to that approach.Maybe I've fixated on a mechanical solution a) because that's how it was designed & b) because it's an old (1991) engine (although only covered 87K).
I do have an electronic solution that will work (it's proven) so maybe that is the way to go. I don't know.
Any idea as to where I might get the thicker gasket made up?
I don't know if TT were cautious as they were working with MB looking over their shoulders.
Cost of a custom gasket could be expensive.
Some take a crude approach of sandwiching a steel plate between two gaskets, but this can affect other aspects like cam timing ( assuming OHC )
Ferriday engineering may be able to make you up something
But really...I see no point at all in opening the engine up with such a low CR already unless you're intending to use more than 15psi boost.
stevieturbo said:
IanA2 said:
Many thanks guys. Lots of v helpful ideas/suggestions.
Maybe I've fixated on a mechanical solution a) because that's how it was designed & b) because it's an old (1991) engine (although only covered 87K).
I do have an electronic solution that will work (it's proven) so maybe that is the way to go. I don't know.
Any idea as to where I might get the thicker gasket made up?
I don't know if TT were cautious as they were working with MB looking over their shoulders.
Times have moved on, electronic tuning has moved on. The standard CR is low enough for a very modest amount of boost without touching the engine at all. So really that would be the best option, rather than choosing to be bound by something designed 20+ years ago and sticking to that approach.Maybe I've fixated on a mechanical solution a) because that's how it was designed & b) because it's an old (1991) engine (although only covered 87K).
I do have an electronic solution that will work (it's proven) so maybe that is the way to go. I don't know.
Any idea as to where I might get the thicker gasket made up?
I don't know if TT were cautious as they were working with MB looking over their shoulders.
Cost of a custom gasket could be expensive.
Some take a crude approach of sandwiching a steel plate between two gaskets, but this can affect other aspects like cam timing ( assuming OHC )
Ferriday engineering may be able to make you up something
But really...I see no point at all in opening the engine up with such a low CR already unless you're intending to use more than 15psi boost.
Long shot this, but can you use LPG with TT. Gut feeling is that theoretically it's possible but probably a PITA. I don't know. Only reason I ask is that I have a nice system already fitted.
Very much so you can use LPG with turbo.
But again all the same things apply when tuning a petrol engine. It requires a suitable system and most importantly someone competent actually tuning it.
What sort of LPG system is it ?
Where most installs fall down, is because there are brainless idiots installing them, with no clue how they actually work. n/a is very easy and forgiving even if they're not installed properly.
Turbo setups will be less forgiving, and would need to be installed and tuned properly.
But again all the same things apply when tuning a petrol engine. It requires a suitable system and most importantly someone competent actually tuning it.
What sort of LPG system is it ?
Where most installs fall down, is because there are brainless idiots installing them, with no clue how they actually work. n/a is very easy and forgiving even if they're not installed properly.
Turbo setups will be less forgiving, and would need to be installed and tuned properly.
stevieturbo said:
Very much so you can use LPG with turbo.
But again all the same things apply when tuning a petrol engine. It requires a suitable system and most importantly someone competent actually tuning it.
What sort of LPG system is it ?
Where most installs fall down, is because there are brainless idiots installing them, with no clue how they actually work. n/a is very easy and forgiving even if they're not installed properly.
Turbo setups will be less forgiving, and would need to be installed and tuned properly.
Thanks that's good to know, I'm lucky I have an ace LPG guy near me. He did my re installation a few years ago. The original was sBut again all the same things apply when tuning a petrol engine. It requires a suitable system and most importantly someone competent actually tuning it.
What sort of LPG system is it ?
Where most installs fall down, is because there are brainless idiots installing them, with no clue how they actually work. n/a is very easy and forgiving even if they're not installed properly.
Turbo setups will be less forgiving, and would need to be installed and tuned properly.
te. Runs like a dream now stevieturbo said:
Very much so you can use LPG with turbo.
But again all the same things apply when tuning a petrol engine. It requires a suitable system and most importantly someone competent actually tuning it.
What sort of LPG system is it ?
Where most installs fall down, is because there are brainless idiots installing them, with no clue how they actually work. n/a is very easy and forgiving even if they're not installed properly.
Turbo setups will be less forgiving, and would need to be installed and tuned properly.
Thanks that's good to know, I'm lucky I have an ace LPG guy near me. He did my re installation a few years ago. The original was sBut again all the same things apply when tuning a petrol engine. It requires a suitable system and most importantly someone competent actually tuning it.
What sort of LPG system is it ?
Where most installs fall down, is because there are brainless idiots installing them, with no clue how they actually work. n/a is very easy and forgiving even if they're not installed properly.
Turbo setups will be less forgiving, and would need to be installed and tuned properly.
te. Runs like a dream now IanA2 said:
Thanks that's good to know, I'm lucky I have an ace LPG guy near me. He did my re installation a few years ago. The original was ste. Runs like a dream now
But is it a very old gas ring type, or is it a modern electronic injection type ?te. Runs like a dream now In order to work, he'd need full control over gas injected, not just what most do and try and rely on a narrowband lambda sensor at idle, and adjust some fuel trims based on that.
That primitive approach often ends up with blown engines.
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