Hello All,

I've got a strange question as my '08R has been doing some interesting things this Summer.

The car will sometimes do a WOT pull that is just silly (feels stronger than ever), however, the pull occurs at 3/4 throttle and only when the ambient is sub 70 degrees. The first merge onto the highway at 6:30 AM every morning is perfection!

Change over to afternoon, ambient is 70-80, partial throttle fun is no more, full throttle fun isn't anything to write home about; yes it's still bloody quick but lethargic. My initial thoughts were knock, cutting boost, high intake temps, heat soak, duh of course it's slower, etc., but late in the evenings (60's), she'll hit or miss a "fuuuuuuullllllll puuuuuuuuuulllllll" too. (sorry couldn't resist).

You other supercharged guys and gals feeling the same? How consistent and temp related are your power curves? Wastegate issue possibly? My car's vitals are purdy good at the moment, fresh plugs, code free, nice flat consistent idle, awesome gas mileage, etc.

Oh, and ahem, don't try and play with an E63 AMG, you'll see taillights, but only briefly as they vaporize before your eyes. I am not a street racer guy (I like to get up to highway speeds quickly and hangout), however, following on some nifty iron's heels onto said highway is always fun. No heels in this case

Thoughts or forgot about it?

Thanks all!

Jeff

 

It's a "too hot IAT" situation.
You may try to upgrade an intercooler pump (helps a bit) or go a methanol injection route (helps a lot).
E63 is a hard to beat opponent, but with a twinscrew and a meth. injection it is possible to overrun it.

 

favourite trick on the E63 is a intercooler pump upgrade.

there is a particular Pierburg pump used on the V12 biturbo which is a *very* good pump but expensive.

it doesn't help on the first pull, but it lets you keep pulling repeatably as if was the first pull.

 

Thanks guys, that makes me feel better. I don't really want to modify anything in that department, I just want to make sure all is well.

Jeff

 

Well, it's better to upgrade a pump, i.e. for a Bosch 010 unit (which is twice more efficient). Original pump are prone to fail and a Bosch pump is much cheaper.

 

The 101 pump will give a better delay in rising IAT and a faster recovery

You need to be doing 50+ KPH before the temps will start to drop at and will fall quite quickly above 80kph

I posted details on this with testing that is posted in the stage 1 intake tube thread

Once simple mod that can help a lot is the fan nod i posted. this switched on the engine fan to full which keeps airflow through the inter-cooler radiator. This keeps the charge coolant as low as possible and aids airflow under the bonnet

That being said, if you read my tests the heat (which is extensive) comes from the headers. The best mod of all is to have the headers ceramic coated and if you have the stage one intake that as well

In the end we are limited by the size of the cooling (both radiators), the lack of under bonnet space and the heat from the headers

We cant do much with the radiators or the lack of space but removing as much of the source of the heat can be done easily.

When on the track I have the engine fan on full. On the runway sprints i turned it off around 100kph (switching back to normal) and back on when idling down

If you have the stage 1 intake get it coated it makes quite a difference and if you have the headers off or are getting the exhaust worked on have them done as well

Cheers
34by151