Yea that will be a good comparison and I definitely want to hear it all buttoned up. I just got mine all straightened out too so it should be fun.

I'll be there third weekend of May so you have time. I'll touch base when I get out there. Only downside is I'm going to want headers that i can't get after I get smoked :(

lol... who knows the girls in the back of the car might weight it down and you might win... still to be decided :-) haha .. I'll hit you up once the headers/kats are in and lets def meetup

Update PLEASE!!!!

Thanks for the write up. I have been thinking of going with the Dinan tune also but hesitated as I had not heard from anyone who had completed it on a vehicle lately. It is good to hear of your experiences and impressions.

How is the throttle response from cruising at say at 40 MPH? I am very interested in hearing your impressions on "tip in acceleration", not a hard stomp, just a 20-30% increase in throttle pressure.

The throttle response is better across the board. The Dinan software, if still available, increases torque and horsepower at all RPMs. Acceleration can be further improved with the transmission software and last I checked it is still available.

so is stage 4 the highest the e53 can achieve with Dinan upgrades? I wonder how much it costs. my indy mech is a BMW guru and he said he drove a 4.6iS with the Dinan Stage 4 and he said it was a rocket!
sounds like once you add up all software and hardware, you're a FEW grand into this upgrade...

Stage 4 is the highest. Stage 4 is a tune that is intended to include their MAF, throttle body and cold air system. The website lists the throttle body but doesn't show the MAF or cold air system. They may not be available.

BC, knowing how nice the Dinan upgrades can be, would you do this ona perfectly maintained 2005 4.4 (tuned like a 4.8iS tho)?
I'm wondering if its worth all the cost for the gains...

dang. well I jsut spoke with a company in Calgary that is an authorized Dinan shop and they said the max I could install on my 2005 4.4i was a stage 3 and high flow throttle body.
seems the older engines have a LOT more goodies to play with.

I didn't think the pieces you need to support stage 4 are available. Most of the 4.6 pieces are no longer available either. But to answer your question. Dinan mods are always expensive due to their supplemental warranty, research, testing etc. And is not unusual they can price where they want as the only source-- as was the case with my 4.6 in 2002.

For your application I would start by increasing the flow of air into the engine and lowering the outgoing exhaust restriction and lowering the effective diff ratios if practical. I think those are the biggest and safest bang for the buck. You can do that without Dinan. If Dinan has the transmission software that is worth the price. I think there are other tunes available but I have no experience as to the benefits but a tune would get more out of the air in/exhaust out improvements because they advance the timing curve some. I wouldn't go to the larger Dinan throttle body because you won't have the larger MAF to go with it. You could replace the clutch fan with an electric one, that get some HP/TQ back. There isn't a whole lot out there but it all adds up. The best improvement for dollar spent is nitrous but it also comes with greater risks. Meth injection will make a shot of nitrous safer but it is not for the faint hearted or someone that does not have the knowledge to work with it and able to identify the symptoms of a potential problem before it happens. I think a 50 shot nitrous and low restriction exhaust only would be a great way to go but you won't find many that agree with me.

Thanks For the input BC. The guy I spoke with about Dinan product said its very hard to source items for even vehicles 10 yrs and newer even so he said as a. At enthusiast to search other avenues.