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Discussion Starter · #1 ·
How much bhp do you recon the 105 could take before components such as gear box etc, since the 120 has a diff gearbox is this due to strength or the fact its a bigger engine.

cheers

:mrgreen:
 

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130-140 before you need to start making major modifications ... new head gasket clutch etc ....

I dont think the 105 was built for handling much power, I think mg would rather spend less cash on components so they can make more profit lol
 

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Monkey Magic said:
130-140 before you need to start making major modifications ... new head gasket clutch etc ....

I dont think the 105 was built for handling much power, I think mg would rather spend less cash on components so they can make more profit lol
agreed I'm sure at one of the meets there was a 105 pushed passed the 140 mark
 
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The engine on the 105, 120, 160 is the same basic engine. The 120 and 160 are over bored 105's ie 1.4 bored out to 1.8. With that in mind, it is not so much the engine that is the problem it is the brakes/clutch/gearbox that will suffer if too much power is wrung out of the lump
 

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Light Sabre said:
The engine on the 105, 120, 160 is the same basic engine. The 120 and 160 are over bored 105's and the 160 is a different stroke to the 120. With that in mind, it is not so much the engine that is the problem it is the brakes/clutch/gearbox that will suffer if too much power is wrung out of the lump
I think its the fact the 160 has VVC rather than the stroke. Seeing as the performance figures are very close through the mid (the 120 is better in fact), and if you add the figures up there is a .4 difference.
 

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The gearboxs n the 105 are the r65 box which cant really take alot of power. if you are tuning with major bhp in mind you'll need an pg1 box out of a 120,160,218 and the clutches also are different
 

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Right here we go.

The ZR 105 uses an R65 gearbox up until about 2003 when they swapped to a getrag box from Ford. The 25 1.4 and 1.6 also use these boxes.

The ZR120, 160 and diesels use the PG1 gearbox. As do the similar 25 models GTi, iS, diesels.

The 1.6 has a larger sleeve (bore) than the 1.4 which gives it the extra capacity. The 1.8 then adds a longer stroke to the 1.6 bore to enhace the capacity further.

The 120 and 160 have exactly the same bore and stroke as each other.

Hope that clears it up.
 
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DOH!

Of course the 120 and 160 are both 1.8's. I was getting meself cunfused as I knew about the diffeent liner, just my soft brain got mixed up between the 1.6 and 1.8 DOH!!
 

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i hate to say it . . . . ;)
 

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yeah i'm just under 130.but i've been told my cam timin is still out.maybe explains why my torgue aint gone u last 3 times i been on dyno.first time after i got timin sorted,second after viper induction kit,3rd after chipping it.all 3 times was at 98ft-lb........

i think it also depends on how u drive yer car.if u thrash it it's gonna buckle under the strain easyer,take it easy n it'll last longer.as with anything!but i would say 140 is max without strenghten some stuff.u could turbo the 105 if u wanted 2 spend the cash doing it.
 

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Humm lot of guessing going on there, careful wot your telling people if your not 100% wot car shares wot componants,
;)

****
 

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The 105 had the R65 gearbox but it has been superceeded by another (IB5???) for late mk1's and mk2 ZRs. The 120 and 160 have the PG1 box with a bigger clutch to cope with the higher torque figures, this is the same box as fitted to F's, Elises and ZSs too. The difference between the 120 and 160 gearbox are the gear ratios, the 160 is lower geared and closer together in ratios for faster acceleration. The 120 has higher gears for more comfortable motorway driving and better fuel economy. Any tuning of any of these cars will reduce the lives of transmition parts to some extent, be prepared for the clutch to show the strains on a well tuned 105 first. Hope this helps Hob.
 

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Discussion Starter · #17 ·
Tah peeps :D
 
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