using E70 N62B48B Throttle body on E53 N62B44A

[bcredliner]

Originally Posted by Clockwork

Well I figured, since I already had the e53 4.8iS exhaust system, software tune (from local tuner company) and Dinan CAI box (with high flow) Donaldson Air filter, I may as well see if I can buy the Dinan MAF and TB. to finish the job..
But then I read that just buying a TB from the E70 N62B48 4.8 could be used instead, as its a larger diameter than my stock e53 4.4i N62B44 TB so that would act as a psuedo Dinan TB for the N62B44 engine.

So I took the chance and spent the $100 on the great condition e70 TB and it bolts up perfectly to the engine (of course) but then the butterfly bore diam is the concern with factory 4.4i air tube.,
So if I can find a way to properly connect an air tube from e53 4.4i MAF to e70 4.8i TB then I can't see this being a failure (but I 100% agree, I should have dyno'd the vehicle before I do this swap and again after to see if any difference).
And I also agree, Air In = Air Out volume equation. Why allow air in if you cant expell it, OR why have a high flow exhaust if you're choking air even getting to engine...... Its funny we are discussing the same theory again as we did in the other thread I made years ago about which kinds of aftermarket air filters to use with a CAI https://xoutpost.com/bmw-sav-forums/...s-listing.html )

I'm taking for granted that the e53 4.8iS exhaust I put on my 4.4 will make it exhale better than the 4.4i exhaust did. I certainly like the exhaust note more so, even if its doesnt

If this was a costly endevour I'd not have ventured down this path but sometimes its fun to see what you can find out.

this small project will have to take a back seat tho to my e31's fuel pump replacement and throttle body replacement jobs this weekend...

The exhaust systems of stock vehicles with extremely few exceptions have too much back pressure. Low restriction exhaust alone will improve performance. No other mods are necessary. Free flow exhaust is always a good value and will maximize gains from other mods.

If you are using the 4.4 intake tube rather than the larger Dinan intake tube the larger Dinan MAF and TB will be of no benefit.