leecavturbo

i know the WRC boys run high C/R.
So why can't my mapper "fit anymore boost in" ?
1.2bar est C/r 9.0:1
i hear all the time "you can run high C/r on decent management"
i am on decent management.?????

Anonymous

...FUEL in one word

leecavturbo

octane rating your on about?

Mike Rainbird

iTrader: (3)

Yes, the WRC cars run Ł20 a litre 118 RON fuel - fill your car up with this, and your mapper will have NO problem....

High compression SUCKS on normal fuel .

leecavturbo

i didn't know they used race fuel?
if so tho i understand that.
what C/R ish do cossy's that run 28psi have?

Stavros

In-cyl pressures is another.

Contary to popular myth, BOOST makes a lot more power than compression ever could.

Also on rallycars they very low geared etc, so the strain aint half as much.

Anonymous

.....mike is totally wrong re hi comp sucks if its a road car...my 7-4-1 off boost is dreadful compared to my 8-1 engine...

Mike Rainbird

iTrader: (3)

Depends on SO many variables (turbo size (both sides), exhaust size, cams, gearing, piston material, bore size etc), but generally I would want to see the number begin with a 7.....

Mike Rainbird

iTrader: (3)

We'll have to agree to differ . High compression sucks if you have to use PUMP fuel, as you have to make too many compromises, the worst of which is retarded ignition, which dumps HUGE amounts of heat into the engine, combine this with being restricted on the boost you can run, and you have a pointless engine that does nothing well .

Anonymous

...if you have to use pump fuel then its more than likely a road car mainly...aint 32psi held from a T4 enuff then...500bhp approx...ok on a track youd turn it down to your sorta power level Mike and be perfectly safe but VERY drivable...Obviously long stud and WRC head gasket are essential items...which incidentally were designed for high comp 9-1 + and 3bar peak boost with no reliablity issues that Stavros mentions.

Anonymous

...your stuck in the 80's IMO Mike...specially seeing as you choose 8 greens over 4 x 1000cc injectors ...A specialist tuner can get 3.5% co on these and good MPG off boost..if you want details feel free to email me

Gary Osborne

well thts great feckin news! so how about 8.1-1, probably with a t34 .63 ,mongoose ,500 cooler ,coilpack, standard inlet/head/cams,
probably on 95 most of the time too.

looking to make as close to 400@ crank as possible .

havnt picked a turbo yet so any advice appreciated and that includes you too :gayflag:

Anonymous

...you will be fine saphcos....400bhp is the limit to std head bolts and grp a head gasket really...95ron will mean you will be more retarded than Mike...but i cant see any real issues see Karl Norris

Mike Rainbird

iTrader: (3)

Phil,
On this occasion, your advice SUCKS. It's all to do with cylinder pressures, and if you stuck an EGT gauge on your high comp engine and did any sort of high speed work, you (and possibly your engine ) would shit itself .

However feel free to mislead people, I'm sure like the post starter, they'll be extremely happy that after listening to people like you, they will be pleased that their engine can't be mapped to the level that the T'internet experts told them it could .

With regard to your comments about eight greens etc, it has nothing to do with being able to achieve a certain CO, but everything to do with spray pattern resolution that can be achieved. My car will pull cleanly from 20mph in fifth gear, with no hiccups or problems. And will achieve 325miles per tank (with will-power) .

Perhaps if you had taken your car ANYWHERE other than up and down the high street, you would realise the truth, but giving advice based on poodling around or squeezing the throttle for a few seconds in the lower gears is bordering on the negligent, as people will take it as read and end up in the same boat as Lee or worse (with a blown engine) .

And APMSLOL at being able to get 400bhp from a T34 on 95 RON - good advice Phil - didn't realise that Karl was God and could change unleaded fuel to Super .

Anonymous

Mike i am certainly not misleading anyone you just have a hang up on heat...was you burnt as a baby? My cars get a good thrashing thank you well not at the mo as its too fast to get near to thrashin it NOT every Cosworth owner uses it on a track infact i bet its only a tiny portion...you NEED to get it out your system that not everyone is in to it as much as YOU....drivability is the key.


Speak to your tuner guys preferbaly one not in the dark ages

As for your comment Mike on saying engines blowing up due to one thing BOLLOCKS....all engines can blow whatever specs. ..yours more than most on 8 greens if one fails You need to drive mine and see how good it runs off boost on an old level 8...get out your own little circle there are other methods out there tried and tested

400bhp is achevible on super yes...on std i said it would be retarded like you..never said it would make 400

leecavturbo

thanks mike, scurrs away to find a unskimmed head
already got the thick head gasket

Mike Rainbird

iTrader: (3)

If you want to recommend people building an engine that is so compromised by high compression that it can NEVER be taken on track or driven flat out, then that is your perogative, but you should QUANTIFY your comments .

In my reading of your post, you implied that it was acceptible to chase this figure on normal unleaded and all you would have to do is run retarded ignition . This is so far from the truth as to be unfunny. You would be lucky to achieve much more than 300bhp with normal unleaded and using that turbo and certainly not on the compression that was suggested .

Lee,
If you want to run more boost, you need to get that compression down. I am not familiar with the LET engines, but if they can take big porting, make the combustion chamber as big as you can and if possible, machine the pistons to drop the compression as near as possible to high 7s / low 8s (as I believe the bore is smaller than a Cossie?).

Anonymous

Mike i dont agree that you could NEVER take my 8-1 engine on a T4 engine on a track on super unleaded...you may run it at 25psi max about 450bhp?...but it would be safe with a good map from someone that knows what there doin..remember i deal with most tuners and every one of em has different views..dont diss others views just cause you are blinkered to one camp.

Mike Rainbird

iTrader: (3)

A minute ago, you were saying 32psi was safe, now only 25psi is? FYI, my engine runs 28psi held and on 7.5:1 compression sees EGTs of 900°C+ on track . I doubt your non-maram shafted T4 would survive the temps and ignition retard required to run even 25psi on 8:1 .

Anonymous

Read my first reply AGAIN.....

Anonymous

.....i dont think all rally YB's run maram shafts Mike ...and they way higher than 8-1 yet they dont melt due to heat

Micky The Finn

my engine is 9.6.1 and runs on optimax.

Mike Rainbird

iTrader: (3)

And has a restrictor that limits the boost to almost single figures at high rpm .

Stavros

And has really low gearing so less load.

And 300bhps worth of 36psi aint same as say 500bhps worth of 36psi.

wayne thomas

Its actually Ł3.94 per litre and its 104ron 4% oxygen enriched

Micky The Finn

peaks at 2.6 bar and drops off to 2 bar,
is low gearing 147mph top speed then?

Mike Rainbird

iTrader: (3)

I was referring to the Elf turbo fuel that was used on the world engines....

Mike Rainbird

iTrader: (3)

What restrictor are you using ? (or are you referring to absolute pressure? )

Anonymous

Well done TIM atlast someone who HAS it properly...so Mike

Micky The Finn

useing a group A 34mm restrictor,quoting just what my boost guage shows.

elf turbo rally fuel is 101.7 ron isnt it?not 118.

ian sibbert

Mike,

Twas even a slight exageration Ł20 P/ltre......Malcolm would be bankrupt by now paying that much for his fuel.....

The restrictor doesn't limit boost pressure only volume....yes it would tail off......but nt that dramatically...

Have you seen an IHI boost curve?

Ian

Stavros

Thats fairly high.

Notice i didnt comment on single figure boost pressures like gaybird, ive been in a WRC car and know thats FAR from true, lol.

But its still 300bhp or so, bit different to running 400 or 500 bhp on high comp and pump gas, esp on summat thats meant to last a long time.

Compressions a funny thing.

Anonymous

..oh go on have another Mike or is rallying not tuff enuff? and you goin spastic over 8-1

wayne thomas

I don't want to get picky but the elf fuels all come in around 102 with varying degrees of oxygen enrichment and @ not more than Ł4.20 a litre

Anonymous

...please hold...Mike is phoning Harvey for help

ian sibbert

ELF TURBO MAX
SUPERCHARGED 4-STROKE ENGINES
UNLEADED
Typical figures FIA Regulation
DENSITY Kg/l at 15°C 0.779 0.720 to 0.785
REID VAPOUR PRESSURE bar ŕ 37,8°C 0.630 maxi 0.900
RON 101.7 mini 95 / maxi 102
MON 88.0 mini 85 / maxi 90
DISTILLATION (°C) 30 % 67
50 % 100
90 % 121
FBP 138 maxi 225°C
% vol at 70°C 34 10 to 47 %
% vol at 100°C 51 30 to 70 %
OXYGEN % % Mass 3.6 3.7 % maxi
LEAD CONTENT g/litre < 0.001 0.013 g/l maxi
APPLICATIONS
- Complies with the FIA regulation.
- Especially blended for supercharged engines of Groups A, N and Proto cars.
- ELF TURBO MAX allows to optimise supercharged pressure and ignition timing thanks to a selection of
petroleum streams which present a strong resistance to pinking on supercharged engine. But the best
results have been achieved thanks to an original fuel blend which combine for the best knock resistance
and speed of combustion. Furthermore the high oxygen content improves the volumetric efficiency of the
engine.
RECOMMENDATIONS
- The best mapping concerning air/fuel equivalence ratio (1.25 to 1.30), supercharging pressure and
ignition advance will give optimum results. The difficulty is that on turbocharged engines, these three
parameters are fundamental and completely dependant to each other.
- Air/fuel ratio must absolutely be checked and re-tuned if necessary because of the extremely high
density and oxygen content of ELF TURBO MAX compared to the usual commercial fuel quality.
- In order to maintain the original properties, and according to Health and Safety regulations of commercial
fuels, this gasoline shall be handled and stored in a cool place and always maintained in tightly shut
drums.
31/03/04

Stavros

If you wanna learn about fuels, its prob wise to read that book about turbocharging by that graham bell geezer, loads in there.

Right down to the exact contents of countless fuels.

F1-era fuel was various kinds of stuff, but some was way more than 102, thats for sure.

RON numbers arnt even HALF the story tho, tons more to it than that, summat that book can explain.

Something with mega high RON level could make a car det a lot sooner than summat with a much lower number, but maybe it could make throttle response poorer, and loads more shit, depends exactly whats in the fuel....

Mike Rainbird

iTrader: (3)

Okay, so I'm a little out of touch (as Phil likes to point out ). I've done a search on t'internet, and the old Elf turbo fuel hasn't been used for quite a number of years, due to it's lead content .

However, this makes it even more difficult to run extremes of boost on the current fuel. I'm just trying to figure out how to work my new scanner to put in the latest WRC dyno sheet I have - so hold ya hosses .

Also, I think I should point out that the WRC cars are using 36-1 pullies, which allows a MUCH improved ECU resolution, which also allows higher figures than shonky L8 .

ian sibbert

Mike,

When you say latest dyno sheet for what engine? and on what fuel...the control fuel used on the wrc has less oxygen enrichment than for example carless turbo ultima that can be run in national rallies in this country...

I think I could hazard a guess at the c/r of the latest focus motor....and my guess would be they are higher than 9:1...

That said low comp lots of boost on a high power unrestricted engine would be the way forward.....

Ian

Porkie

iTrader: (1)