So if you change to 200 cell cats should you do a remap?

Or if you then do Manifold / Headers and 200 cell cats should you do a remap?


Will you get benefits from just the hardware without a software update?

Does the ECU have a little give with fueling and timing etc? Surely it does?


What are peoples opinions and what results have you achieved?

Thanks

Mark

 

I think high-flow cats and a tune are the best bang-for-your buck mods you can do. For the 4.3L cars, I think it's a must-do mod to get the performance the factory should have given them.

 

Like yourself, I have fitted 200 cell cats.

Before fitting I did some research to see if it would be required for an ecu upgrade.

Rich is better informed here and can probably correct me if wrong but....

To answer one of your questions (does the standard ecu adjust) the ecu fitted to the V8 Vantage reads the knock sensors and reduces or advances detonation accordingly.
This is to compensate for various fuel octane levels, the quoted power of 380bhp (on the 4.3 litre) being acheived at 97 octane fuel (uk rating).

Therefore running higher octane fuel should result in more power and likewise running less the ecu will adjust without damage to your engine at reduced power. In the link below a figure of 3.75bhp/octane of fuel is mentioned although not totally linear.

Here in germany 102 octane is freely available.

That said I'm sure an ecu flash/upgrade will also see improved results but is not a necessesity.

I would also be interrested to see rolling road results to see if an ecu/reflash would be worthwhile.

Here is the thread for the information above and makes interresting reading (3rd post down)

https://www.pistonheads.com/gassing/...&t=978848&i=60

 

Not to go off on a tangent, but...

The Pistonheads post is indeed interesting reading and I have to confess to not having perused all 93 pages (!), but the usual misinformation about "low grade fuel in the US" appears to be regurgitated on the first page, by someone who should know better.

Bamford Mike describes 91 octane fuel in the US as "low grade" yet this is an AKI rating, which is equivalent to about 95 or 96 octane RON in UK/Europe.

A 97 RON fuel would be equivalent to North American (AKI) 92 or 93 octane, which is readily available in many parts of the US and Canada.

Your 102 octane fuel in Germany (presumably RON) would be equivalent to, or slightly better than 94 octane AKI, which is readily available in my part of Canada; not sure about the US, though.

 

The Vantage, like most modern cars, uses a MAF to monitor airflow into the engine and therefore determine the fuel to be metered accordingly. These types of systems are generally very tolerant of normally aspirated intake and exhaust modifications because any changes in volumetric efficiency are automatically compensated by the MAF system. Provided that you don't mess with the intake near the MAF so it's readings are still accurate. So, like the vast majority of cars with MAF based systems, you don't need to tune with your modifications.

Now, the question you should be asking is do you WANT to tune. The throttle response dialed into the stock engine is not inline with what it should be (IMO) for a sports car. Likewise, the engine is conservatively tuned, which can help to ensure engine longevity at the cost of torque generation. Things like overly retarded timing and somewhat rich mixtures help to keep exhaust temperatures lower and generally protect the car from an inattentive or overly agressive owner or other external possibilities. VelocityAP and others generally offer canned tunes that are still safe but less so and noticeably wake up the engine. I am extremely impressed with my VAP tune. It's the only power modification I've made to my car (which admittedly started with the factory power pack) and the only one I plan to do. So IMO, you should WANT to tune.

 

The ECU remap was the best mod I did to my 07 V8V. I put on the VAP headers, 200 cell cats and the ECU tune and the car came alive. Throttle response was much better- It finally drove like a sports car. Before doing the remap, it was so tame compared to my BMW M3. Aston apparently limits how much throttle is applies in 1st and 2nd gear (?). Note - these changes also add considerable exhaust cacophony, which I like.
My ECU tune was customized by VAP to my car.

 

To remap just for the cats, no not necessary. But if you get headers for sure better to get a full dyno retune.

Go with Eurocharged, you will absolutely love their tune, best money I ever spent on my Aston.

 

It's still not necessary. As I said, the MAF compensates for VE changes due to bolt-ons.