360 -> "more" w/ low-end torque?

[Austin David]

Hi!  I have a new 360S, Duratec w/ wet sump.  This is a street car and will be mostly toured / grocery runs.

 

Now that it's barely broke in, I'm thinking about the motor.  Curious if anyone has direct before/after experience with ITBs and a sub-420 spec?

 

I've poked around a bit, the upgrade path mostly looks race-oriented with cams and injectors as well as the RBTB or ITB, depending on kit.  I assume that will mostly push my torque into higher RPM and let it breathe better... but I also believe that will largely trade some low-end torque for top-end performance.  And per grocery thing, I'm not sure I want to make that trade.

 

Any direct experience out there?

 

@KnifeySpoonyshared a little of his experience (esp wrt 420R -> RBTB)

[CarlB]

I do not have direct experience with your engine, but generally this is what you should expect. Expect the power curve to be improved some. The length of the runners will determine were.  Long runners add to the low end, short runners to the top end. The cam has the largest effect and if you do something outside the range of the cam it will not change much.  The engine will be more responsive but low speed will probably suffer. The big thing on that is if the system uses a map sensor. even with a map sensor it will not be as smooth as a stock set up at low speeds.  

[KnifeySpoony]

I would add that on a 420 w/ RBTB, the fueling is excellent. Yes, the throttle spring is strong, and the response is so immediate that it is possible to "kangaroo" as the Brits say. The immediacy is amazing, the sound is phenomenal, and TBH I can't imagine the car without the ITBs at this point. Worth it for the sound alone, IMO. 

[Austin David]

did you see any power-related benefit, or mostly with response and sound?  I saw your other post(s) about fuel economy, so not sure if you have other gremlins in there.  Mine is pretty thrifty.

 

Also I can SEE my plenum contracting just by blipping the TB at idle.  I'm sure there's a fair restriction in the intake.  Still on the stock filter, FWIW

Edited May 24, 2022 by Austin David

[KnifeySpoony]

I did the RBTB from new, so I didn't get to experience the power bump, but it's well-documented. CC promises 10HP, but I think most people seeing ~15-20Hp boost on dyno runs (on a 420 platform). I still need to see what my actually economy is - I think my long idle/warmup is skewing my numbers dramatically. It gets great mileage on track actually (where it spends most of its time).

[Austin David]

17 minutes ago, KnifeySpoony said:

It gets great mileage on track actually (where it spends most of its time).

What's your track mileage?  30+?  I'm only in my 4th fueling and I think the aeroscreen made it better.  If I'm not driving like points are free it's shockingly high.  If I drive to match others in Atlanta I'm still north of 30.

 

Mostly I'd want to be sure it's reasonably fueled (like 12-14.7 I assume) and not super rich for no reason.  After that I'd hope mileage were largely a function of throttle position...

[KnifeySpoony]

Ha, no. It's only good mileage compared to my last track car. My exige got about 6mpg on track. The 7 is getting closer to 8. So 50% improvement! 5mpg on track is not atypical for many cars. It's all relative...