Mr C

iTrader: (2)

If I had a YB 2Ltr engine for circuit use with a Borg Warner EFR 7064 Int WG on L8 ECU, and wanted to reduce the torque curve on the dyno graph so that it didn't have a 300ftlb increase between 3200-4200rpm, what options do I have?
I'm quite happy to have a reduction in torque from the 490 ftlb (it would help traction and gearbox) but keep the 460 BHP top end if its possible.
I'm almost starting from scratch with the engine build and don't want to be changing coolers and pipes and inlets if I change to the slightly larger BW EFR at a later date so what are the pros and cons of fitting these parts below on the above set up, will they add/reduce torque/BHP and affect throttle response etc;
.A/S /Hart inlet cover over a 4x4
.70mm Throttle body over a 63mm 2wd
.using 70mm pipes on a 100mm intercooler over 63mm pipes
.or using a 63mm piped 70mm core intercooler


Is there a method of boost control that I could add that would help flatten the torque curve without changing the ECU and adding £1000s to my bill?

Caddyshack

Power is Torque X Revs so reducing the torque should reduce the power too but a mapper could play with the boost and move the power around a bit. I have high and low boost with the same turbo as yours, on low boost I get just over 400bhp and it feels massively different to the 469bhp in high boost.

My charts are on my 205 4x4 Cossied Pug thread somewhere.


If you are using the car on track then go for the best intercooler you can afford, it will all work on 63mm and 70mm I am sure.

The Hart inlet does improve flow / power if the map allows.

Mad_Mat

I would have thought some form of clever boost control was in order. Perhaps by gear.
I think in most cases this is handled by the ecu. I'm not sure if the L8 has the ability to allow you to cap boost in lower gears etc.

Mr C

iTrader: (2)

I've been recommended the A/S inlet and the power I want will be possible on a 63mm piped cooler and 70mm core so good to have it confirmed Caddyshack thank you. I do need to find a suitable large injecter for 550BHP Max but mappable on L8, I've had in confirmed it is possible to reduce boost at set revs using L8 if traction is constantly an issue at certain RPM, good to know, only a few tuners will map this though so Harvey Gibbs or Stu at MSD will be given a call in the future.

costina

iTrader: (1)

Adjusting the intake cam can change the torque curve but not as much as you want.

A good tuner should be able to advise better solutions to your problem.

stevieturbo

If your ecu is incapable of giving you good boost control options, then something like this would do.

It claims to offer boost by gear, boost by rpm, or boost by vehicle speed. Obviously you need to provide that information to the controller.

gear would need a speed reference.

So in the absence of a suitable speed signal, boost by rpm would allow you to tailor torque/boost by ramping it in.

If you make large changes to your existing boost patterns, you will need all the tuning re-checked to ensure everything is safe.

There are other controllers out there that can offer similar...usually much higher priced though

https://sirhclabs.com/

There are also lots that make similar claims...but fall short feature wise. I've never used this one, but on paper it looks excellent value for money for such a controller.

turbotrev

Out of interest why do you want to reduce the increase in torque between them revs?

Is it causing a problem?

I thought that was one of the benefits of using that turbo setup?

Cheers Paul

Caddyshack

He wants to help the gearbox longevity and aid traction

turbotrev

What gearbox is he using?

Is traction an issue with the big sudden increase in low down torque?

Cheers Paul

Mark Shead

No it’s not. He is hopping to match what I did with Toby’s engine but he isn’t there yet as far as we know.

Mark

turbotrev

I guessed not as you mentioned before it’s not a problem.

What is he hoping to match exactly??

Cheers Paul

Mark Shead

Toby’s 468hp and 490ftlb.

Mark

Caddyshack

469, I think but I may have rounded up.

turbotrev

Oh you mean just power?

Choosing that turbo setup is gonna give that big early torque figure so I don’t understand why he wants to decrease it....

Cheers Paul

Mark Shead

Same here lol. Just turn the boost down in the areas you don’t want the tq it’s simple.

Mark