Quite the opposite. I talked with DW about ITBs on a tub and he reconed it'd be a complete waste of time and money. But you can afford to go very big on the TB. Blue will use K Series -- what -- 48mm. Cheap as chips.
Tuning turbo time!
- Thread starter craigb244
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Tuning turbo time!
Mate had a 4inch TB on his turbo tigra and it was awful to drive slight touch of the pedal and it would rev straight up, could not launch his car evan with launch control so went down to a 3inch and all above problems gone
im still using the standard punto75 TB and cant understand why anyone would want to go larger unless they gonna have over true 200bhp
eventually if i get compressor surge i will use a 42mm TB
Zak
im still using the standard punto75 TB and cant understand why anyone would want to go larger unless they gonna have over true 200bhp
eventually if i get compressor surge i will use a 42mm TB
Zak
You can dial all that out -- the over sensitive throttle -- either with software or buggering about with the throttle quadrant. Fact is that the 1108 high boost tubs run better with a tricker (40mm) than a smaller one and 48mm isn't completely OTT for an injected forced induction mill (it's what the 1.4 16v NA cars use, for the most part). For mega power, you need a mega TB, or so it seems.......
AlexF
New member
You can't map out the throttle sensitivity without cuasing other problems (like lag) IME.
Will depend on the software.
AlexF
New member
I don't understand what you mean.
The only variables are the amount of fuel and the spark advance....
Alex
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cool. ill defiantly use the larger TB then
if anything it will be better cos im running it now and know its faultless.it won't.. it's down to the fact that you move the pedal a tiny bit and this huge throttle plate moves, the engine could be breathing at capacity when you hit around half throttle travel. because of this, tiny moves in the plate are multiplied.
you also have acceleration enrichment to factor in, that'll use the TPS signal.
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you can (and i do) use mapdot on MS1.
might upgrade it, might not. i'll get it running first.
might upgrade it, might not. i'll get it running first.
ITBs & forced induction works well if you put the R&D in. That said it means that something like this is out of the question for most people with 'centos.
I've found that it's not that hard to make your own & for my application the butterflys want to be rather small, 26.5mm right now. I'm getting the thick end of 185bhp from 2 sets of MPI Sei' injectors, one about where they're mounted on the stock manifold running at 3 bar, then a second set in front of the throttle plates running at 5.5bar.
Fueling is intresting sub-7.5psi fueling is done purely with the 3 bar injectors, over 11psi is with the higher pressure set as primaries with some support from the lower pressure set at higher rpm. Between 7.5 & 11psi is the transition period where weird mapping voodoo goes on to deliver the best performance & response.
I've found that it's not that hard to make your own & for my application the butterflys want to be rather small, 26.5mm right now. I'm getting the thick end of 185bhp from 2 sets of MPI Sei' injectors, one about where they're mounted on the stock manifold running at 3 bar, then a second set in front of the throttle plates running at 5.5bar.
Fueling is intresting sub-7.5psi fueling is done purely with the 3 bar injectors, over 11psi is with the higher pressure set as primaries with some support from the lower pressure set at higher rpm. Between 7.5 & 11psi is the transition period where weird mapping voodoo goes on to deliver the best performance & response.
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right engine is out the black car.
The plan now is to fit the turbo engine into my car and run is as a N/A for a bit (will be slow with low compression). when i say (a bit) i mean go for couple mile drive. I just want to make sure everything is solid and to seat it all after i swapped the pistons.
The plan now is to fit the turbo engine into my car and run is as a N/A for a bit (will be slow with low compression). when i say (a bit) i mean go for couple mile drive. I just want to make sure everything is solid and to seat it all after i swapped the pistons.
Stonenewt,
you have a highly tuned cento turbo with a very high output we know you have a lot of money, time, and effort going in to your track car,could you help us lot out and give us a rough size the throttle body should be for a 1242cc cento turbo please!
and if you dont mind the size of your throttle body on your track seicento
you do have a custom inlet manifold with lot more extra bits compared to rest of us just a rough size
many thanks Zak
you have a highly tuned cento turbo with a very high output we know you have a lot of money, time, and effort going in to your track car,could you help us lot out and give us a rough size the throttle body should be for a 1242cc cento turbo please!
and if you dont mind the size of your throttle body on your track seicento
you do have a custom inlet manifold with lot more extra bits compared to rest of us just a rough size
many thanks Zak
To qualify this I'll say I've tried the calculating route & that turned into a red hearing so now I'm just working on gut feeling for developments. This means what I come up with may well be the 'wrong answer' from an engine tuners point of view but it does what I want.
So I have 4x26.5mm TBs, the equivalent throttle plate area of a single 53mm TB, which if you think about it isn't that big considering the 160bhp 1800 K-series lotus shipped in the 160 Sport came with a 56mm TB iirc. That said the size of the throttle plate is strongly effected by the geometry of the runners & trumpets. With my throttle plates being close to the inlet ports I need a smallish plate to keep the runner to port angles sane.
So I have 4x26.5mm TBs, the equivalent throttle plate area of a single 53mm TB, which if you think about it isn't that big considering the 160bhp 1800 K-series lotus shipped in the 160 Sport came with a 56mm TB iirc. That said the size of the throttle plate is strongly effected by the geometry of the runners & trumpets. With my throttle plates being close to the inlet ports I need a smallish plate to keep the runner to port angles sane.
AlexF
New member
Depends on your software. Most throttle pots are non linear. Most throttle quadrants are. All that's happening is that a small movement of your foot is -- as is -- converted to a lot of air/fuel mix being dumped down into the engine. So, either a cam profiled quadrant or/and some kind of home brewed FBW should sort it.
As to the variables, well, Megasquirt is written in C code, compiled -- it's not a fixed inviolable peice of granite like a program put together by the Microsofties . Dunno if the module exists, but you could ask for it (and launch/traction control).
Interestingly -- or not -- DW did a piece touching on this a month or three ago in PCC in which he was forced to eat his calculations about how big a TB could be. (And my apologies to Brooky who I told off for being over optimistic.)
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Engine is out!
turbo engine is in!
engine started up "OK" 5mins ago. sounded really rough to dark to investigate.
turbo engine is in!
engine started up "OK" 5mins ago. sounded really rough to dark to investigate.
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had to suffer rain/snow/hail/wind today but got a lot done!
yesterdays rough running was simply the coolant sensor been disconnected.
the engine ran sweat.
all I have to do tomorrow is bolt the zorst on. load up the ignition map and fuel base map can get tuning
leaving oil cooler out for now.
yesterdays rough running was simply the coolant sensor been disconnected.
the engine ran sweat.
all I have to do tomorrow is bolt the zorst on. load up the ignition map and fuel base map can get tuning
leaving oil cooler out for now.
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