Jump to content


Photo
- - - - -

How To Get 100bhp From A 1275 Block


  • Please log in to reply
37 replies to this topic

#31 Sony Crockett

Sony Crockett

    Learner Driver

  • Noobies
  • PipPip
  • 18 posts

Posted 18 January 2010 - 12:33 PM

A lot of people only reads how much BHPs an engine has... but I think it´s more important to have a reliable, fun, and good sounding engine.

Turbos are a good way to produce more power and torque from and engine, but, what about the turbo lag? It just kills me...

A mini with a N/A big block engine, with a good head, good exhaust, short ratio gearbox with x-pin diff and straight cut gearbox it´s a blast to drive.

I think you don´t need so much power for such a small, light car...

#32 MarkGTT

MarkGTT

    Super Mini Mad

  • Members
  • PipPipPipPipPipPip
  • 528 posts
  • Location: Shropshire

Posted 18 January 2010 - 12:51 PM

Turbos are a good way to produce more power and torque from and engine, but, what about the turbo lag? It just kills me...


with all other aspects constant - if you cant live with the lag fit a smaller turbo (than the 'standard' T3), run a sensible amount of boost and it will be very fun to drive.

#33 Wil_h

Wil_h

    Up Into Fourth

  • Members
  • PipPipPipPipPipPipPipPipPip
  • 3,244 posts

Posted 18 January 2010 - 01:55 PM

I agree, a propper spec'd turbo engine will minimise lag (or boost threshold as it is actually called).

Lag was a big issue when turbos first appared, the metro was never brilliant and such cars like ethe Saab 900 were also a bugger to drive. The 'lag myth' has propogate from such cars, and other that are porely though out.

As I said above, my 998 turbo does not drive like a turbo mostly but has over 80 bhp. Cammy highly strung NA engines are more of a pain IMO than the off boost low power of a turbo.

#34 t25dave

t25dave

    Just On Tickover

  • Noobies
  • Pip
  • 9 posts

Posted 19 January 2010 - 08:58 PM

i think the n/a & turbo engines are not a like for like comparison anyway, at the end of the day a turbo is a fantastic way to gain in a sence free power, but the differance of completely instant reponse from a N/A engine compared to even a properly built turbo engine they are worlds apart

my turbocharged road legal track mini is built to have good power from very low down the rpm range up to 6500rpm is the absolute maximum, i tend to change gear before that as the max power/torque tails off at around 6250rpm & 6000rpm is ideal!!! is'nt laggy due to turbo choice

my daily is a 998mini n/a (i'll keep cam choice to myself) is 78.6bhp at the at the flywheel, old cooper 295 head, with some mild porting & polishing & a weber 40 on a 4"intake manifold, old 1275gt gearbox & i can outrun a fair few more modern hot hatchs to about 62mph, the sprint is over by then anyway, between my gearset,head,cam,weber it'll pull completely clean from 1200rpm to 7500rpm with no flat spots, the ignition is megajolt

for the average guy/girl i think a more modern classic mini with fuel injection & a proper 90bhp kit + a few old fashioned modifications to the induction, throttle pot/butterfly etc & a decent tuned exhaust, not a cheap sportex will see more than 90bhp at the rolling road, to make that feel quicker maybe a 3.44 final drive, then a programable ecu when the funds allow then think of a cam change

having a n/a mini with a modified engine & a turbo-charged mini also i have the direct comparison & i personally feel you get a far faster throttle responce with a n/a motor than a tuned turbo!

i've not had a tuned fuel injected mini but i've had a tuned rover k-series & that has instant throttle responce like a well setup tuned carb motor

wether your mini has a turbo, carb or fuel injected its personal preferance if you've drove the different types

with a bit of knowledge & selecting the right componats a 1275 100bhp daily drivable a series is definately possible, on alot smaller of a budget than what alot of companys/so called specialists out there will charge you, i personally would'nt spend any more than £2000 on an engine & non-straight cut box

#35 minifan333

minifan333

    Stage One Kit Fitted

  • Noobies
  • PipPipPip
  • 72 posts

Posted 24 August 2010 - 03:52 PM

Hi.
Some little question:What could be the total cost for get 90-100hp(real hp)
from an a-serie egnine(1275 spi for example)?
How about "prebuilt" engines from MED,is better buy one of those or rebuild a "normal" engine?
http://www.med-engin...mp;vlang_id=156
Thanks

#36 AndyMiniMad.

AndyMiniMad.

    Up Into Fourth

  • Members
  • PipPipPipPipPipPipPipPipPip
  • 3,290 posts
  • Location: Under The Bonnet.

Posted 24 August 2010 - 04:45 PM

Power. Im sorry but i dont subscribe to the Bhp is everything idea. In my opinion it is better to produce an engine with a good torque curve. Even if you can get 100 bhp from a 1275 or 1293, whats the point if it all happens at 6750 revs and is all gone at 6800? Me i prefer an engine that will accelerate smartly between 40 and 80mph in top gear. Useable power thats what its all about, not a mad chase to get bhp figure to tell all your mates about. Im building a 1380 with lots of nice, (expensive) bits, and am not expecting much more than 100 bhp but would love the same figure in torques.

#37 richieg

richieg

    Mini Mad

  • Members
  • PipPipPipPip
  • 165 posts

Posted 24 August 2010 - 04:57 PM

What about a supercharger for more instant response?

#38 rick.spi

rick.spi

    Camshaft & Stage Two Head

  • Members
  • PipPipPipPipPipPipPipPip
  • 1,686 posts
  • Local Club: "WOT NO BRAKES"

Posted 24 August 2010 - 07:23 PM

another fact to the matter, a cammed 100bhp NA motor will want revs for the power, a similar powered turbo unit wont need as many revs to fly (so more reliability in theory) will be more drivable in town than a cammed NA motor, wont be as fuel consuming if you foot isnt always on the floor. im not saying either is worse but for a cheapish, reliable, 100bhp a series turbo is a good option.

im sure the whole reason they made the metro turbo was for these reason as if they tuned the NA motor any more it would have become a little raunchy.

obviously this wont be the case on all applications but when bringing money into it i think on a low budget the turbo option is a good one.




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users