Rod-Tarry

Im not reading it like that. More how high can you run not High v Low. If you want a 700bhp engine you will want it to work as well as 2017 technology allows. Nothing to do with a YB matters so your right about that, but some like to push the envelope & see the rewards of that.

bj928

i'm following this thread and seeing what people come up with, i'm building a 32v v8 5.4 ford engine, that will be fed by 2 gt35r turbos, i have decided to go for a cr of 9.3:1, the bottom end will be good for at least double the power it will be running, so although the engines are different, the principal is the same

turbotrev

I dont think other tuners belive you NEED to go low comp for 500/600hp its just they prefer to go that that route

Cheers Paul

nixon_2wd

This design has been unchanged since the 1950s, and is currently being revolutionized by TJI. +15% efficiency, 1/3 reduction in fuel consumption, lower EGTs etc. Follow F1 and you get updated on the latest tech.

It's not the location im talking about, but the fact that the mixture is ignited from the centre and outwards. This is slow and inefficient as the flame front has to travel a great distance before all the mixture is ignited.

Mark Shead

It called not progressing lol.

Mark

turbotrev

I knew youd say that lol

And your right but others may may either not agree or just like doing it their prefered way?

Cheers Paul

Mark Shead

The question is have they tested this style set up and what where there results.

Mark

turbotrev

At a guess I'm saying other people would of and have, otherwise they'd choose something different surely?

Cheers Paul

stevieturbo

It'll be a big task converting a Cossie head.....

And all these newfangled things always make big claims, reality often proves different. Hence why engines have changed so little over the past few decades.

Loomer

I think it would need direct injection to make the most of a funky TJI system rather than dumping fuel from behind a valve

nixon_2wd

To get the most out of it you need direct injection, but you would still see a huge gain over conventional spark plug on a port injected system. Remember, it's all about avoiding knock. The distance the flame has to travel directly dictates when ignition has to occur. Being able to ignite all the mixture at once allows for higher compression ratio = higher efficiency = less fuel per hp.

Direct injection also have a major flaw, which is carbon build up in the intake ports as the port injector is no longer flushing / cleaning the ports. Look at N54 and the issues with DI.

To retrofit TJI on a YB we would need a high pressure fuel system for the prechamber ignition, and a specially designed tji-injector that fits in the stock spark plug hole. There's room for such a system in the YB head.

stevieturbo

Looking at some petrol DI cars...they're worse than cars from the 40's or 50's for shite build up !! Hell, they're as bad as dirty diesels. And they call it progress ?

For maybe 20-30k they might remain clean and efficient...after that they're bound to be going downhill.

Modern cars really are turning into bundles of shite, forced because of silly emissions targets which I'd say can be counterproductive because the technology is so poor and unreliable for long term cleanliness.

Loomer

It's Czech Mate

I'd never go low comp in a car used on the road, they always drive shit off boost. Tuners who still go low comp are stuck in the dark ages IMO

turbotrev

What comp ratio did the cossie have that you drove buddy?

Was it mega low comp?

Cheers Paul

It's Czech Mate

Couldn't tell you exact specs, all cars i've been to buy though back in the day, numbers in the low 7's were mentioned but you never really know without the full detail/spec to hand. Suffice to say they felt flat as a fart and never got bought.

I often find (found) that owners are happy with what they have because it was the dogs bollocks when they splashed the cash, but it doesn't mean they're any good.

Caddyshack

If you could run a turbo car at the same comp ration as the best n/a car then you would, if it didn't melt then you would do it so surely the highest comp ratio that you can get away with is the best?

Mark Shead

The current F1 engine is restricted to max 18-1 although none have said they where above that.

Mark

Caddyshack

Wow, that is pretty big.

Caddyshack

So, my 2.4 might be at this level with a 10 yr warranty if kept under 12000 rpm....lovely , I will take 2

When can we start? Lol



That is bonkers, how do they stop it melting?

Mark Shead

By charging about 750k per engine

Mark

Caddyshack

Oh, that is a little outside the budget. 2.2 and 8000rpm? Lol

stevieturbo

They use Tesco 95RON

Caddyshack

The fuel of champions

dingla rs

iTrader: (2)

Be down next sat with the 200 block for u mate

COLEYST200

iTrader: (3)

thanks very much mate

GARETH T

Question i want to ask everyone is, with regards to the old YB what do you think has changed in the tuning world in the last 15 years to allow higher compression ratios to be used?

markk

iTrader: (2)

Nothing, my YB engines were at 9:1 in 2001

800bhp

Better engine management, intercoolers and turbos

GARETH T

great answer!

GARETH T

better ecu's and intercoolers?? in what way?

we have got a better variety in turbos available now, but the differences are not huge!

Caddyshack

The spec r intercooler moved things on in a big way, the modern ecu' s are not only much faster (compare a 90's computer to one from the last 3 yrs) but they can monitor many other parameters. Fuel has improved so the ecu can go closer to the limits.

Coil on plug moved things on.

If you doubt it just look at what had to be done for 500 bhp in the 90s, now a standard engine can do it.

800bhp

There not huge there MASSIVE

Mark Shead

Better understanding of what is needed to make them work at that level and keep the power there.

Mark

GARETH T

i don't agree with any of your points!
very modern ecus may well be faster, but the question should be how fast do they need to be? engine speeds haven't changed, 15.4 degrees of ignition advance was the same in the 90's as it is now!

GARETH T

Do you honestly think that the engineers that worked on this engines in the YB touring car days didnt understand what was needed?

Caddyshack

So, Gareth, what is your point? Cars are making far more power, failing less and running a higher compression. What is your argument?...should we all be running lower comp and to what end?

800bhp

They done a great job for what they had available for there days. Things have moved on since the 80's.

GARETH T

my point is for people to stop being so blind into thinking things has significantly moved on in the yb tuning world.
You should run the highest compression ratio you can.

Caddyshack

A few things I have learned from 4 years on this forum 1) Mark Shead knows his onions. 2)listen to what Mark Shead is telling you and 3) Cosman likes bumming things.