What size engine ?

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1152cc turbo A-series now with 125.7hp at the wheels !

AUSSIE Turbo mini forum >> http://boostmini.justboard.net/

https://www.facebook.com/boostmini

The 998 is being built to 1220cc 202head 1100 crank 68mm GR flat top Pistons etc

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Simonw
Brisbane QLD
1st car - 1964 Mini Panelvan 850
Previous - 1978 Leyland LS 1275 Gold
- 1969 Mini K

The turbo would need to come on very early .... I can't recall the stall for the auto I think it's about 1200rpm ... Hang on let me check that ..

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Simonw
Brisbane QLD
1st car - 1964 Mini Panelvan 850
Previous - 1978 Leyland LS 1275 Gold
- 1969 Mini K

Definitely is going to have to be a drivable semi daily street car , so no crazy boost , inter cooler etc .
I guess I would need to asses the cost benefit factor , just thought it might be an interesting exercise

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Simonw
Brisbane QLD
1st car - 1964 Mini Panelvan 850
Previous - 1978 Leyland LS 1275 Gold
- 1969 Mini K

Turbo won't come on boost that early , but a gt15 with the right cam should see boost from 2500rpm with an 1100 , depending on engine load . But for the street that is perfect , most of the time you are above 3000rpm , so full boost whenever you press the accelerator.

Definitely would be very drivable for everyday though. Auto turbo would be pretty cool

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1152cc turbo A-series now with 125.7hp at the wheels !

AUSSIE Turbo mini forum >> http://boostmini.justboard.net/

https://www.facebook.com/boostmini

the great thing about turbo cars is there are no restrictions on plumbing, just trade offs. You could put the turbo at the end of the exhaust, but the lag would be unbearable, and it might not drain properly, leading to James Bond smoke screens!

Super chargers are great regarding throttle response, however if you can size the turbo to spool at 2500 rpm then provided your compression ratio isn't ridiculously low you won't suffer in terms of drive ability.

My NA swift doesn't pick up until 3000rpm. If your mini spools at 2500 then you're laughing.

use a so called oil-less turbo and that problem is solved

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Rover 214 atm ....

Probably should start a turbo auto thread but..
Doc I remember reading you had adjusted your matic to shift at 5k was I dreaming ? What was the goes there ?
Just in relation to finding a reasonable spool on rpm to match a turbo ...
On that note :
What would be the reasonably highest compression you could run in this mystical auto turbo engine given the above comments ?

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Simonw
Brisbane QLD
1st car - 1964 Mini Panelvan 850
Previous - 1978 Leyland LS 1275 Gold
- 1969 Mini K

Matic 998's C/R was 9.0:1 originally.
I would limit the new motor to 10.0:1 in an auto, but 10.5 or even higher is OK for a manual where you are not loading it up from 1500rpm off the mark. If hi-stall converters existed you could run higher.
This is assuming you will run 98, or 95 if unavailable. Many servos now only keep one or the other.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

My Polo has an 1197cc turbo engine. Boost starts at 1750 rpm. So there are tiny little turbos out there that could suit the mini and boost from low revs. Disclaimer: it only has 66kW...

Also. Google Culprit Racing for a sub 10 second street registered Torana with the turbo mounted under the boot. Amazing what is possible!

M

Great info M.
It would be great to hear of small turbo models capable of low rpm boost.
Also was wondering today whether low boost turbo addition would add enough usable horsepower to justify it being there .... For example the potential for a 1220cc to achieve over 100 hp or at least around that ..
Anybody wanna comment ?

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Simonw
Brisbane QLD
1st car - 1964 Mini Panelvan 850
Previous - 1978 Leyland LS 1275 Gold
- 1969 Mini K

If you look at modern car engines they will typically have 100Nm of torque per litre and about 40 to 60kW per litre in naturally aspirated form. So the new MX5 has a 1.5l engine with 97kW and 150Nm. That makes it more powerful than the comparable engines in most small hatches but about the same torque.

Turbo engines like the Polos are all about reducing fuel consumption by having the lowest friction from the smallest engine. These will have 130 to 150Nm of torque per litre and 55 to 70 kW per litre. The torque is also spread over a wide rev range so they are tractable and not peaky.

The trouble with the polo is that boost starts at 1750. Below that it is just a 1197 cc engine trying to move 1025kg. Put 4 people in it and try a hill start! You're either stalling or riding that clutch and revving it like a tool to get away!

Mine is the base model so it makes 66kW, the next one up makes 81kW or 108hp from the same capacity. I wouldn't mind betting the only real difference is software. I see no reason why a 1200cc A series shouldn't make 100hp and be very driveable.

M