Tuning the 1108 FIRE

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Tuning the 1108 FIRE

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Feb 5, 2006
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Hi all,

I'm about to start building a lightweight Cinq Sporting for hillclimbs/sprints which will involve serious tuning of the 1108 engine... can anyone share their experiences of this, particuarly with regard to power vs. driveability?

Cheers, John
 
Well options are:

1242 swap - If its allowed!

If not

Then a Columbo + Biriani (sp?) 280 fast road cam

40mm Throttle body

Breathing mods such as filter and zorst

Uprated valves, followers and springs - then up the rev limit a bit.

Port and polish, multi angle valve cut.

Turbo

bored and honed inlet manifold and larger inlet plenum.

Enlarged air inlet bob
 
How far do the regulations allow you to go John? Is it standard engine capacity but free otherwise, and is forced induction allowed?
 
Randomman said:
bored and honed inlet manifold

Please explain that one...Ive never heard of that

Randomman said:
and larger inlet plenum.

As part of a totally redesigned induction system tuned to a specific powerband yes, but tbh you'de be best using a TB on runner design (1 TB per port!)
 
PM Oldschool, or visit clubfirepower.com - They have lots of info on the FIRE engines and tuning of. also, there are a few people running the 1108 in the 750 motor club in custom chassis which are highly modified

I believe Tricker... is getting around 100bhp without a turbo from his.
 
cinqysxmk2 said:
I believe Tricker... is getting around 100bhp without a turbo from his.
Tricker has the benefit of using a 1242, which is prohibited by the MSA build regs :).
 
Yeah...but the Trofeo cars run about 11:1 CR and that needs 105RON Octane fuel...and thats somewhere about £7 a litre I think!!!

But power does go up in relation to a raise in Compression ratio!
 
arseofbox said:
Yeah...but the Trofeo cars run about 11:1 CR and that needs 105RON Octane fuel...and thats somewhere about £7 a litre I think!!!

But power does go up in relation to a raise in Compression ratio!
Which also reduces its lifespan.
There are many tricks but most dont share them as on the 750 motor club some people make a lot of money with those engines.

Personally I would get someone to build the engine that has done it many times.

Inlet manifold design will make a massive difference if that is free.

Search for guy croft for some ideas.

CFP is also a good place to start (although I notice you have already posted).
 
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arseofbox said:
Yeah...but the Trofeo cars run about 11:1 CR and that needs 105RON Octane fuel...and thats somewhere about £7 a litre I think!!!

But power does go up in relation to a raise in Compression ratio!

Not forgetting tescos stuff that is 99ron and is cheaper than optimax.
 
Thanks guys, with regard to the 1242, check out my blog at www.nitrane.co.uk/blog for the lowdown on my war of words with the MSA on this one :mad:

Target is 120bhp to be competitive, as well as getting weight below 700kg with the cage. The regs are here for anyone interested.

I'm meeting oldschool next week to discuss feasibility.

Cheers, John
 
120BHp..normally aspirated? Youre mad...thats gonna need revving to 5 figures to be any use!! :D
 
arseofbox said:
120BHp..normally aspirated? Youre mad...thats gonna need revving to 5 figures to be any use!! :D

Hey, now there's a thought! Seriously the power has to be in that region else i'm not going to bother. I can go the AX/106 route for an easier/cheaper life.

100bhp/litre is an achievable target for a well-tuned, well-engineered n/a engine.

John
 
nitrane.co.uk said:
Hey, now there's a thought! Seriously the power has to be in that region else i'm not going to bother. I can go the AX/106 route for an easier/cheaper life.

100bhp/litre is an achievable target for a well-tuned, well-engineered n/a engine.

John

We will get it!
 
Well... after a very long chat with Oldschool (cheers Peter!) Project 500 is back on the road :D

The plan is to build a trick 1108 to start with, which will allow us to evaluate both the engine and the chassis set-up, and see how competitive it all is. Full technical support is being given by GSR Engineering. The nitrane website will soon be updated with a full technical spec, project plan and photo diary, but here's a sneak preview...

- lightened & balanced bottom end
- big valve 1242 'head, gas flowed with 3-angle seats and lightweight valvetrain
- custom cam
- MPi with flowed and matched manifold, and reworked TB
- 4-2-1 mild steel manifold into race system
- GSR twin-cone induction system
- Full RR re-map

The shell will be caged and undergo a serious weight loss programme, and be equipped with AVO coil over suspension and uprated brakes. Plan is for competitive debut at the end of 2006 season, ready for a full campaign next year (y)

Cheers, John
 
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