MarkD Chip vs Miller MAF w/ Basic Chip

[EatsHondas]

I've been researching the hell out of both options, but I can't decide what I want. Some say the Miller MAF is amazing and increases driveability significantly while others say it never worked correctly or made no difference. Besides smoothness and better initial off-throttle response, is it normal to feel a bump in HP/low-end? I've seen Miller's dyno graphs, they say a stock M20 with a reasonably tight motor will see a peak gain of around 20 HP/TQ, but that's after seeing dyno time + tuning (with their WAR chip? It doesn't say). I don't want to mess with that or pay $400 for a chip.

MarkD's chip is widely recognized as one of the best chips for the money for the E30, and it's significantly cheaper than Miller's MAF and basic conversion chip.

I have stock injectors that I will sending to at some point MEPEH to be cleaned and completely rebuilt. I don't care for the M50 injectors hack, stockers flow fine for a stock motor with room to accomodate a chip. I understand the "better atomization" angle, but most people who swapped to green-tops probably had gunked-up, factory injectors to begin with.

So two final questions:

1) Why the mixed results with Miller's MAF?
2) Has anyone tried both and picked a clear winner?

[digger]

people probably put a miller maf on engines that run like a turd beforehand and polishing a turd doesnt work........the stock setup works well when properly maintained.

[mccor023]

I've had both, and believe the car ran stronger w Mark'd. However I have kept my Maf w ka cai because i like the clean look an sounds. Im not a race car driver and therefor Im not fretting over a few ponies. If I have 135 whp or 150 whp it doesnt matter to me at this point because my car is still healthy and a lot of fun.
Thats my .02, but if I could do it all over I would have avoided braking my stock air box and afm brackets and left it the way it was.

[EatsHondas]

2 votes for the MarkD then eh? Definitely makes sense. Cheaper, less intrusive mod that still increases fun factor. I have a rather large vacuum leak right now and 180k-old injectors, so I know I'll see a benefit from getting those sorted out.

[digger]

2 votes for the MarkD then eh? Definitely makes sense. Cheaper, less intrusive mod that still increases fun factor. I have a rather large vacuum leak right now and 180k-old injectors, so I know I'll see a benefit from getting those sorted out.

Thanks for the responses guys, I think you're steering me in the right direction.

i will clarify my vote is not for MarkD, my vote is for get the thing maintained as good as you can stock first. i dont believe in off the shelf chips at all if you want to get the most out of what you have. you need a custom tune. years ago i had a custom tune done with piggyback and also on another occasion an emulator without a piggyback and the cusotm tune is the far better approach. if you want a cheap setup an Ebay chip from known decent supplier is the best way

[EatsHondas]

i will clarify my vote is not for MarkD, my vote is for get the thing maintained as good as you can stock first. i dont believe in off the shelf chips at all if you want to get the most out of what you have. you need a custom tune. years ago i had a custom tune done with piggyback and also on another occasion an emulator without a piggyback and the cusotm tune is the far better approach. if you want a cheap setup an Ebay chip from known decent supplier is the best way

So dyno time is worth the extra expense and hassle over a simple chip from a professional tuner? I'm guessing there's not much to be gained from a stock M20 other than advancing the timing up to the limits of 93 octane. But there would definitely be smoother driveability from a custom tune? That makes sense, I'm just wondering how much of a difference it would make.

[mccor023]

I would listen to digger, his m20 is crazy stupid sick. Loath envy all of the above.

[bimm3r82]

From my experience I purchased a cheap ebay chip and was happy with it for years.. My afm wasnt doing well so I decided to go with the miller maf setup.. after I ordered I actually ended up opting for the whole maf and war chip package... Once I got it all in i realized the other issues i had which were minimal and now that everything is up to par and running well the difference is significant. to be able to modify your fuel and ignition is nice, especially if your going to keep doing mods down the line.. Ik you didnt mention the war chip but that would be another upgrade with the maf.. I seem to rambling now but yea I like the maf.. and its user friendly for noobs (warchip) ..

[digger]

So dyno time is worth the extra expense and hassle over a simple chip from a professional tuner? I'm guessing there's not much to be gained from a stock M20 other than advancing the timing up to the limits of 93 octane. But there would definitely be smoother driveability from a custom tune? That makes sense, I'm just wondering how much of a difference it would make.

i'll say there are gains to be made with a custom tune in my experience, how much it? depends every engine is different. if you cant justify the additional cost and hassle then just get the cheapest off the shelf plug and play chip as they are still an improvement. if you find a supplier with decent reviews you cant really go majorly wrong. there are lots of suppliers of chip other than MarkD so i would research and look for reviews.

the 8.8:1 B25 engine does not need 93 IMO it is hardly a knock limited engine and i would not bother with it, something around 91 is probably better IMO. this review of 8.8:1 M20B25 chip in an 1989 525i sort of reinforces that, but it may be a unique result and not representative. 98RON is equivalent to 93 in the USA and 95 is equivalent to 91 in USA




when i dynoed my powerchip 98RON i got the same results as the review above. At WOT there were midrange gains only (no more topend or lowend) which probably reinforces the lack of need for really high octane fuel on a stock M20 there is a bit too much variability to get anything more than what the lower octane chip helps. however when custom tuned the gains were across the board like with the 95RON chip in the article but only better.

[EatsHondas]

Torque seems good above, but what's with the anemic 70kw/94 horsepower? Even for a worn motor, that's pretty weak.

It blows me away that the car ran stronger with a tune for 91 octane, I assumed 93 would only have the capacity for more gain. If stock M20's ran a higher compression ratio, would it benefit from a more aggressive timing tune and higher octane?

Don't mean to spew questions, but why would BMW set the compression so low on an NA engine?

[digger]

Torque seems good above, but what's with the anemic 70kw/94 horsepower? Even for a worn motor, that's pretty weak.

It blows me away that the car ran stronger with a tune for 91 octane, I assumed 93 would only have the capacity for more gain. If stock M20's ran a higher compression ratio, would it benefit from a more aggressive timing tune and higher octane?

Don't mean to spew questions, but why would BMW set the compression so low on an NA engine?

dynos are a tuning tool dont worry about the actual numbers just the relative changes.

93 is just more knock resistant fuel than 91, so unless you are knock limited it is pretty much a waste of time using it for the purposes of making more power.......

[Herr Faust Schinken]

Torque seems good above, but what's with the anemic 70kw/94 horsepower? Even for a worn motor, that's pretty weak.

It blows me away that the car ran stronger with a tune for 91 octane, I assumed 93 would only have the capacity for more gain. If stock M20's ran a higher compression ratio, would it benefit from a more aggressive timing tune and higher octane?

Don't mean to spew questions, but why would BMW set the compression so low on an NA engine?

I think it has to do with a lot of the world having kinda crappy gas, some euro m20s run a 10.1 compression from the factory

[digger]

I think it has to do with a lot of the world having kinda crappy gas, some euro m20s run a 10.1 compression from the factory

the European B25 from the same year are also the same low CR. i believe it was something to do with a fuel crisis or emissions etc some BS anyway

[Pocket Chant]

the European B25 from the same year are also the same low CR. i believe it was something to do with a fuel crisis or emissions etc some BS anyway

There was a fuel crisis during the 70s, it's what spawned the Eta and the horrible 4 Cyl. Mustang IIRC.

[EatsHondas]

There was a fuel crisis during the 70s, it's what spawned the Eta and the horrible 4 Cyl. Mustang IIRC.

the European B25 from the same year are also the same low CR. i believe it was something to do with a fuel crisis or emissions etc some BS anyway

No kidding. Damn Arabs nerfed my M20... Couldn't have been emission reasons, E30's don't have EGR thank Christ...