turbotrev

Question for those of you guys that are running efr turbos in rwd cossie's...

With the super quick spool up and initial huge increase in torque low down in the rev range how do you find traction?

Any better or worse than on previous T/GT series turbos?

Cheers Paul

Caddyshack

My 205 was bonkers in 2wd mode on acskyline box, the tyres were not great but it spun up in 4th under full throttle, I suspect new tyres and a 6 degree beam would have been very different

ajamesc

I'm sure ade doesn't have to bigger problems and he has loads of power and torque. Mark would be the best person to ask

Mark Shead

The efr is more progressive on the throttle so even though they produce more tq they are more drivable..

Mark

lee2cossies

iTrader: (2)

How much more responsive is a efr over an sx200? I'm going to be changing from a sx200 soon and moving to aftermarket management.

Mark Shead

I haven't got a true back to back test on the same engine I have posted a gtx3071 to a s200 on a 2lt evo then I changed to a 2.2lt and then on to a efr. The efr was always going to monster it.
The S200 is a great turbo but the efr 7670 will always outspool it out response it and out power it. It's not like going from a Gt to a s series turbo.
I actually think I may have a 2lt evo graph which does compare I will have to try and find it but it was over 5years ago.

Mark

lee2cossies

iTrader: (2)

Thanks for reply, I'm looking at getting the 8374 as it has potential for 700hp at a later date when I put together a suitable bottom end.

Mark Shead

A 9180 is needed for 700hp.

Mark

jaiscossie

need some 285 or 295 rear tyres!

turbotrev

So would you say traction would be more or less of an issue comparing it too a more regular gt30 500hp spec setup?

Do you mean by progressively accelerating as in to be careful that traction is maintained?

I would of thought that a huge early on power rise so quickly would be worse for traction?

Cheers Paul

Caddyshack

You don't get a sudden spike of power/ torque / boost so traction is better on the efr. Think of it like stamping on the throttle compared to feeding in the power quickly but more progressively

turbotrev

So on a rwd big power car traction will def be better than with other turbos?

I still don't quite understand how though....

Someone must have a rwd car that's been recently converted?

Cheers Paul

ajamesc

The way I'm reading what there saying is yes there's a large jump in power and torque. But it's not like an on off switch you can more accurately control the amount of power and torque you make and put down with the throttle?

Caddyshack

Tyres grip and slip like most things, if you want to remove something from a surface then a shock like a bash (shock loading) will make it come off more easily that just a constant force as it overcomes the inertia.

The way an old Skool turbo comes in is nothing then boom and that shock ungrips or unsettles the car. With an efr it comes in much earlier and more progressively, you get more power and torque throughout the rev range but without the big globs all at once.

Big turbos can sometimes help grip as the power comes in once the car is already rolling.

My car was converted this year and I had it 2w and 4wd switchable on the skyline box.

If you look at a modern twin scroll turbo BMW, (I had 2 twin scrolls) they are torque limited (held back on the maps) in 1st and second as they just produce too much power for the grip available.

stevieturbo

Just because something can make boost early....doesnt mean you have to have that happen all the time.

The joys of boost control.

But if you've a laggy turbo....you aint gona make it spool up significantly faster via boost control.

turbotrev

Gotcha.

Why more so with an efr turbo than any other?

Cheers Paul

turbotrev

If an efr is more progressive the way it comes in on boost then wouldn't it have a mellower power curve on the RR graphs?

Cheers Paul

Caddyshack

That just depends on who maps it, lots more is available lower down, just depends on how soon they ramp it up....the main thing is that you are not waiting for it to come to life all of a sudden, it is just building all the way from nowt.

Rod-Tarry

Running long gearing on mine helps with grip. I simply don't appear to have the probs most have with half the Power. However you need the Power to pull such gearing. I have a very tall 1st gear as well to increase Torque capacity of the box. Add- Proper Rear beam, Jag diff-loc, chassis connectors & decent coilovers with twin springs to stop squat + 235 wide 888's & you have grip even with 800+bhp & a GT42. You guys only seem to concentrate on the engine. Its a fast car you need not a fast engine they don't always go together.

3doorcozmess

The only person I know of who has a efr powered 2wd saff is username Albertodelgado I believe he's about 600bhp ish it would be interesting to hear his opinions.

Si

turbotrev

Totally understand Rod, they way my car is set up currently is so all the different areas you mentioned all work together as best as possible from what I want from the car.

Out of interest what ratio diff do you have Rod?

Ever thought of getting a custom sequential box done Rod?

Cheers Paul

turbotrev

Must be more than one guy out there with a setup like this surely??

Cheers Paul

Mark Shead

I have quite a few out there they just don't use pf.

Mark

turbotrev

Have any of these customers mentioned traction being better/worse than in previous turbo setups?

Do you spec the suspension, transmission, etc or these cars as well?

Still waiting for my pal to pull his finger out and get his car done and mapped by you etc so he can take me for a spin in it, prob won't be till next year now though

Cheers Paul

Mark Shead

I normally spec everything. IMO there is no downside to a efr set up unless you are stuck in the past and it's amazing how many tuners are so they make little to none improvement in how well modern tech makes these car drive.

Mark

scoooby slayer

iTrader: (4)

Some r888s alone will make a huge improvement they are by far the best tyres I've ever used

turbotrev

I am very intrigued I must say, I'm after a new turbo early next year so will reserve judgement until I've been out in my mates car.
I could be converted.....

But I was genuinely interested in traction issues

Cheers Paul

Caddyshack

Tyres have a massive impact and also I think a lot of riffs would benefit from a refresh as don't lock as well as they should. The beam and shocks are also very important for traction.

The only consideration with an get is if you can afford the turbo, manifold, downpope, injectors to suit and the mapping, if all are YES then accept no substitutes

Albertodelgado

iTrader: (1)

Mark recently mapped my 2wd with EFR 8374.. it has very good driveability on max boost setting 2.4bar
OK is has wheelspin in 1st when you floor it from rolling start, but after changing to second gear the wheelspin is disappearing with no wheelspin from there.
The driveline is Tremec TKO600 gearbox with Ford motorsport 9" inch diff 3.6 ratio 520Nm tarmac and 235/40/17" Toyo R888's tyres.
Rear beam is a 6 degree one which has been set to 1 degree camber at the rear.. coilovers are Black Art Design ones

Adam-M

Very well spec'd car

turbotrev

Agreed!

You have a nice motor there buddy, specced beautifully.

Cheers Paul

3doorcozmess

Nice spec,

Do you have a RR graph

Cheers si

Albertodelgado

iTrader: (1)

thanks mate.. no RR graph unfortunately from the 2wd.. when my 4x4 with almost same engine spec gets mapped early 2017 by Mark we'll probably put it onto the dyno over there, but that's still a few months away