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(Post Link) post #1 of 18 Old 07-03-19 Thread Starter
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Twinspark turbo builds

Hi everyone, new to the forum and would like to ask a few questions and see some ts turbo builds people have done.

I plan to build a cf1 2.0 ts turbo using oe compression.

1.Does anyone know what the max boost the engine can safely handle is

2. Could i get away with just a rising rate FPR or is a remap vital

3. I hear turbo nutters had several successful builds but also that autodelta in london did not, has anyone else turboed a ts and whats the outcome been like?

4. Obviously a proper manifold and turbo set up is ideal and id like to eventually, but will a jtd manifold and turbo with the vanes welded shut be okay just to start me off and see how the engine likes forced induction?

I think thats all the questions i have for now, thanks
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Hi Alessio, nice project coming up.

1. When it comes to boost levels in an unopened OEM motor, it is all down to knock / detonation prevention. It is mostly managed by pulling back the ignition advance. 0.5bar is safe without pulling out to much spark advance and not having active knock detection. 0.7bar is safe with active knock detection.
B. Another easy way is enriching air fuel ratio.
C. Lowering compression (but that means motor open)

2. Taking 1B (above) into account, over 0.2bar, the standard injectors will run out of duty cycle (maxing out). Adding fuel pressure to the fuel rail only helps a little, bigger injectors or more injectors are needed to provide more fuel at higher boost. If you get "SLIGHTLY" bigger injectors, the stock ECU could probably compensate, but a remap would be needed for significantly bigger injectors. The other option is to add secondary injectors with a small fueling ECU just before the throttle to enrich the air when in boost. It also helps cooling the air intake.

3. There are a few turbo TS motors out there, but not enough. Brent built a spectacularly strong TS motor in conjunction with Turbonutters, but he went more towards the built motor side with forged conrods and forged, lowered CR pistons. TBR racing, Clive Dension racing has strong Nord turbo motors, but that is a whole different fish to fry.

4. Jtdm (16V) exhaust manifold is perfect, so is 1750 tbi. Diesel motors only rev to 4500rpm and needs to be on boost at 2000rpm so their turbos are SMALL, It won't work in a petrol 2.0 environment. The 1750 turbo can work for a low boost application in a 2.0TS. Best to look at other options like volvo / subaru / opel
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(Post Link) post #3 of 18 Old 08-03-19 Thread Starter
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Hi gertie, thanks for the information

What size/what car can i get the injectors from that will work with the ecu?

Ill try and get a flange made up to mate the manifold up with a normal turbo in that case, something like a t25 or 28 is what i need then?
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For not opening the engine, lower boost, higher CR, I would go T25, lower boost threshold, but it might run out of puff on the higher rpm. The T28 will come in later, but keep on in the higher rpm. Personal choice... I would go T25 for street ability.

For bosch injector selection, this is the ultimate sheet:
Stan Weiss' - Electronic Fuel Injector (EFI) Flow Data Table
The 2.0 is 170cc/min, the 2.5 injectors are 190cc/min. The 3.0 is 240cc/min. That is as far apart as I would attempt a ECU self learning experiment.

For remap / extra injectors with small fueling ECU. I have a set of 2nd hand Volvo T4 injectors available. They are Siemens 314cc/min(same form factor). I have bought aftermarket 400cc/min injectors for my two race cars as I couldn't find another set of Volvo T4 injectors and I wanted to keep things the same between them.

Last edited by Gertie; 08-03-19 at 12:09.
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Originally Posted by Alessio155 View Post
Hi everyone, new to the forum and would like to ask a few questions and see some ts turbo builds people have done.

I plan to build a cf1 2.0 ts turbo using oe compression.

1.Does anyone know what the max boost the engine can safely handle is

2. Could i get away with just a rising rate FPR or is a remap vital

3. I hear turbo nutters had several successful builds but also that autodelta in london did not, has anyone else turboed a ts and whats the outcome been like?

4. Obviously a proper manifold and turbo set up is ideal and id like to eventually, but will a jtd manifold and turbo with the vanes welded shut be okay just to start me off and see how the engine likes forced induction?

I think thats all the questions i have for now, thanks
All of what Gertie says for a road application. But even for (low boost) road I would do the following -

1. Fit a proper oil cooler and intercooler - there is enough space ahead of the radiator on a 155. Perhaps bigger injectors will be better than two sets
2. Make sure you compensat for the oil pressure 'leak' created by plumbing in the oil circuit on your turbo.

3. I would not use the JTDM manifold - it is both inefficient - no proper pulse staggering betw cyl' and the narrow manifold tubes were designed for peak torque/power at +_ 4500rpm. The twinnie a will rev to 7000rpm everyday all day so you will be choking your engine and possibly not getting the best out of your turbo. Get a proper bespoke steam pipe or stainless steel manifold made and make sure it is properly braced and mounted so as to avoid it cracking

4. Change the tank fuel pump to an uprated one, this is an easy swop out win but you will get more volume and pressure.

5. My application was for a track car and maintaining both oil pressure and dealing with oil surge is a problem - two motor tear downs later - I am still trying to resolve. In both instances the BE bearings called time - and on the last occasion killed my crank. No other damage was caused but oiling on these motors is a problem and the decades older Nord motors oiling and their sumps were way better designed. I built a turbo Nord as well and while it's a built agricultural it makes wads of power with no oil pressure issues.

Be rest assured this project will be a money pit so plan carefully and don't be guessing. But a boosted twinnie is actually a thing of beauty - when it works. I think Gertie's has proved the far more reliable so far. Turbonutters will offer helpful guidance. Good luck and shout if you get stuck with anything - as lots of school fees have already been paid by me...
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(Post Link) post #6 of 18 Old 08-03-19 Thread Starter
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Thanks for the information guys, i think i might have to revise my overall plans now and budget a bit more.

That said i may try the whole jtd set up because im hard headed and i already have the bits sitting around

Looking at fiat coupe 5cyl i think the manfiold will fit if i chop the fifth part off as stainless ones can be bought for reasonable money so that may be an option.

How should i limit the oil feed if i was to use a journal bearing turbo? Also for the oil sandwich plate, is there a specific one for the car or any old one will fit?
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(Post Link) post #7 of 18 Old 08-03-19 Thread Starter
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I also made this for the car
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Yes you have to limit the oil to the turbo.
I bought a oil sandwich from Mr Turbo and had to modify it very slightly to get it to work instead of the the OEM water / oil cooler thing. I think I used the OEM center screw part.

You can try the jtd setup as is, it will spool extremely early, but choke off just as early. With a proper waste gate the back pressure will not be such a problem, but you might overspool the turbo and limit its life. If you have it and want to give it a bash, be your own guest, but don't spend money buying it.

Last edited by Gertie; 08-03-19 at 13:25.
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(Post Link) post #9 of 18 Old 08-03-19 Thread Starter
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I got the whole manifold/turbo all for free so i dont mind breaking it if thats the way things go, i think ill give it a go and if it blows then it blows, at least it will give a definate answer on what will happen with this set up.

The jtd manifold has a port on it which i planned to put an external wastegate on, id imagine that should take care of the back pressure, but we'll see, i may just be being foolish as usual
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I also made this for the car
where did you make this bud?
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(Post Link) post #11 of 18 Old 09-03-19 Thread Starter
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Hi mate, i made it in the garage one night, i ground away 'twinspark' (i kept the A to put the cloverleaf badge on) then took the 'turbo' from a fiat coupe 20v cam cover. I used chemical metal to set it in place.
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Thanks, i meant where did you get it painted?
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(Post Link) post #13 of 18 Old 10-03-19 Thread Starter
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I did that in the garage too, polish up the writing with sandpaper and i painted it with red wrinkle paint
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Thank you
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(Post Link) post #15 of 18 Old 11-03-19 Thread Starter
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No problem
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(Post Link) post #16 of 18 Old 4 Weeks Ago Thread Starter
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What would be involved with using a 1750 turbo and manifold?

Whats the wastegate set at etc etc...
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(Post Link) post #17 of 18 Old 4 Weeks Ago
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It would be much better matched than diesel turbo.

EDIT: The waste gate itself is low boost, the controller makes it high boost

Last edited by Gertie; 4 Weeks Ago at 19:30.
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Thanks gertie, i asked because i thought i had a chance to get one but it fell through.

I have finally come to terms with the diesel turbo being an utterly horrendous idea😂, im going to make an adapter to mate the jtd manifold to a t2 turbo and go from there
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