M20 top-end and exhaust build

[e30slidewayz]

I recently purchased a new head built by Myster-e here on the forum (thread here http://www.r3vlimited.com/board/showthread.php?t=226540). This is the first top-end build I've done, so I'd like to get it done right the first time and I'm looking for any suggestions that would get me on the right path. Keep in mind that this is my daily driver, spiritedly driven mind you.

Some pertinent info on my current setup up is that it's an '89 325is, stock M20, jim conforti chip, stock injectors, K&N highflow filter with stock AFM, supersprint catback with everything else stock.

Along with installing the head, I'll be throwing in some 19lb injectors. Does anyone have a suggestion on what injectors to use, I'm thinking bosch but have no clue on what part #. I'm also wondering if an adjustable cam gear will give me any benefit. I'm assuming yes as the timing should be retarded with the reground cam and the cam gear would allow me to advance it. Correct me if I'm wrong on this; would love to save money if I didn't need it. If needed, I'd probably go with the one VAC offers because they use oem M20 cam gear teeth to assure no slipping.

I'm definitely going with the new Miller MAF conversion with the WAR chip. I understand that it will really wake up the engine, especially with the new head. I spoke with Brody from Miller; he suggested a 3" MAF housing using an M50 intake boot along with the WAR chip. Since the WAR chip can store 4 different programs, I'm hoping that I program it to chill out some of the loping that the 290 cam will cause so it will be streetable as well as having another all out track setup and maybe an eco setup. I have no idea of the capabilities of what the new chip will allow me to do. Any input on this?

I'll also be installing a set of headers... MSDS probably, any other suggestions that won't break the bank? I plan to hit them with some VHT flameproof primer, wrap them up in some jegs lava tape, then hit them with some VHT flameproof clear to keep the temps down.

I've heard some people suggest adding ZDDP oil additive when using a reground cam in the M20. What are y'all's thoughts on this? I'm planning on it, didn't know if it was needed or what.

Any light shed on any of these issues would be very much appreciated, thanks in advance.

[e30slidewayz]

morning bump

[nando]

shorty headers are a waste of time and money. the only advantage over stock is weight.

you need something with ~28" primaries minimum to do anything significant. up to 36" works well. shorties are in the order of 12-18".. useless.

as far as ZDDP - Mobil 1 15w50 has 1200ppm of ZDDP and is only $24 for 5 quarts at walmart. doesn't get much better than that. if the cam is new, you need to keep the engine above 2000rpm for about 20 minutes to run it in.

if you're breaking the engine in too, set your throttle stop so it doesn't go below 2k and drive around, vary the RPMs, but keep them down for the cam break in part. after that I prefer the "drive it like you stole it" method.. :)\

also - the 4 tunes thing is stupid. Unless you're knock limited on your local premium fuel, and you have to run race fuel at the drag strip or something, there's no reason to change fuel grades, and there's no reason to change your fuel or timing maps "for fuel economy". they're 3D, they automatically lean it out under light loads/cruising and richen it up when you're at WOT. You don't have to switch to an "economy" mode because it's built into the maps already! that's the entire point of EFI. marketing BS at it's finest....

[e30slidewayz]

Thanks for the help. Had no idea about the chip tuning. I'll probably just end up using 2 tunes, one for daily to keep the idle somewhat smooth and then a lopey-as-f**k tune for track days. And I've actually been looking for long tube headers for a while this morning. Can't really find any that aren't cheap no name brands; either that or they are over a grand. Any suggestions? I believe the cam is new as well, so thanks for that info. I'll add some ZDDP and set the throttle cable where its running at 2k and let it set for 20 or 30 mins then drive it like a bat out of hell.

Still looking for info on what injectors to run and the adjustable cam gear.

[nando]

I'm telling you - you don't need a different tune for track and daily driving! there's no such thing as a "lumpy" tune. when you are at idle it's using a different fuel and timing map than if you were at WOT. the computer automatically adjusts the tune for different conditions.

the *only* reason to have a different tune is if you brough the car to a dyno, did one full dyno tune (fuel *and* spark) for race gas, and one for pump gas. and that's assuming you need race gas to reach MBT before the knock threshold (most M20s will not need it).

otherwise, the switchable maps thing is 100% marketing nonsense. EFI makes all of that moot.

is your bottom end new or just the head? I wouldn't let it set at 2000rpm for a long time, you want to vary it a little.. you just can't let it drop below that threshold. especially if the bottom end is new too.

the bavauto longtubes were decent and not too expensive ($700?). Dunno if they are still good quality or of the price has gone way up though.

[e30slidewayz]

Ahhhh, got ya on the tuning thing. The bottom end is all stock and is not new, plans in the not too distant future to change that though. And I did see the bav auto headers, they're at $750 now. That's a little, especially with the miller MAF and chip. Was hoping to get off around $350... gotta pay to play I guess. Anyways, thanks again.

[nando]

yeah, at $350 you're looking at either quality used headers or ebay junk. I got my RD headers for $400 (barely used), so good deals are out there if you're willing to wait.

[e30slidewayz]

I just spoke with Jeff at IE and asked him about their headers. He said that they were doing a run of shorty headers and they should be ready in about 30 days but no plans to do long tube in the forseeable future. I asked if he would do a run of long tube if I could put a group buy together... waiting for a response.

[nando]

they're just ebay headers, dude. IE doesn't make any of that stuff.

however, given that IE is the middleman - you at least have somebody to go to if there's a problem with fitment. there's not anything technically wrong with ebay headers, they just generally use thinner materials and the fitment is hit or miss.

[e30slidewayz]

Well screw that route then, I figured a company as well known as IE would be coming to the table with a better product. From his email, it sounded as if they had to "make" them; I was assuming in house. Guess I better sell some of these parts I have laying around to get up some scratch for a bavauto set. For sale thread coming soon...

[einstein57]

I know IE is supposed to come out with a new line of headers. Saw them in person last week. Downersp started a thread about them. Instead of VHT i'd order some ceramic coating from eastwood. Very affordable and easy to apply.

These seem to be the better ebay headers.

http://www.topspeedauto.com/ProductCart/pc/viewPrd.asp?idcategory=226&idproduct=2250

http://www.ebay.com/itm/BMW-E30-325i-325ic-325is-87-91-Race-Spec-Performance-Exhaust-Header-Headers-/390354666522?pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr&hash=item5ae2f3841a#ht_889wt_831

[e30slidewayz]

Thanks for the info. I saw these headers on ebay, I didn't know if they were a decent set or just the normal ebay riffraff. I'll probably go ahead and get these, the price is more in my ball park. I'll also check out the eastwood coating. I've just been reading up on the benefit of heat wrapping and thought it'd be a nice project for myself.

[Wanganstyle]

Longtube headers are awesome. These (Hardy and Beck) sound like Baritones when ran uncorked. I'd probably run OEM headers over shorty eBay ones as the fit/advantage/cost delta is too great.

some china factory will probably knock off longtube headers eventually.

Mid pipe fit is very tight, some wiggling had to be done to clear e36M chassis X brace and H crossover pipe fabbed for O2 (and O2 harness extended)

[e30slidewayz]

Wow, nice. I'm actually in the process of getting a custom set from a member here on r3v. They look nice and he'll hopefully be offering them to everyone very shortly. I haven't been told a price as of yet... so we'll see.

[e30slidewayz]

Guess I'll start tracking down an adjustable cam gear. Noones chimed in yet, I'm just going to assume that it will give me some benefit as the timing should be retarded with the new head work. Hate to pay $250 for that VAC one though. I'll have to see about a cheaper route that still maintains quality. Any suggestions?