Dinan vs. Mark D Chip (91 octane)

[BrooklynMW]

Sorry if this is a repost. Looking for differences between these two chips. Has to be 91 octane, cuz in SoCal, there ain't no 93.

Anybody have experience with both? How do they effect the power on the low end/pickup? Gas mileage?

thanks in advance.

[DmcL]

ooh thats a tough one..

i have run both and compared both and dinan seems a little stronger at full throttle up to about 5600rpm but beyond 5600rpm it sucks and forces u to change gear. also dinans tune runs basically stock part throttle maps so u get no extra power when just cruising around normally so if ur light footed driving around in traffic the potential to see a slightly better MPG reading is not there. on the other hand marks has tuned part throttle maps so more power driving normally and also his doesnt fall short after 5600rpm.

on that basis i would recommend marks.

i also sell chips but the only thing i have that is stronger than both marks and dinans may or may not run on US 91ron, also im not entirely sure how the lambda sensor affects the air/fuel ratio of a tuned chip because all the M20's over here never got a stock O2 sensor so what i tune it to run is with it runs if u know what i mean..

[blefevre]

I have a 91 Dinan and 93 MarkD. For me it seems the Dinan had more useable torque in the 2k-4.5k range but the MarkD is much better 4.5K up to redline. I really doubt the butt dyno is able to tell a difference between the two that much though, probably all in my head.

[DmcL]

that sounds about right.. im an E30 tuner myself and i have seen/compared both tunes and dinans does tail off higher up so ur butt dyno would be correct this time.

[BrooklynMW]

For me it seems the Dinan had more useable torque in the 2k-4.5k range but the MarkD is much better 4.5K up to redline.

This is probably the most usable advice for me, thanks. I'm a fairly conservative driver, and see 2-4.5k more often than I see 4.5-up. So considering what I'm looking for out of a chip is more power on the low end and better gas mileage, the Dinan might be the one to go with.

I have heard amazing things about Mark D's chip and have been planning on getting one. But considering I may never take my car on a track, the Dinan seems to be a bit more practical.

[bmwstephen]

just make sure you get one from Dinan directly. as you may or may not know, Dinan had different variations for each m20 platform based on ECU number and year. I bought a used one off a member here thinking that all late model m20s were the same and still felt a loss of low end torque like my stock chip. as it turns out (because I had an extrude honed intake manifold), Dinan had a special tune for that and manage to restore some power by readjusting and advancing the ignition map a little more. Definitely great on gas mileage, OBC average 23-24 hwy mpg on my stock tune, I'm getting 28-30 hwy now (although the rising gas prices sort of killed that saving since I can only use 91 octane)

[BrooklynMW]

Ya. I just thought of something though. Even though I'm currently in California, where the maximum octane is 91, I may be going back home to New York sooner or later, where I can fly free with 93. I think I might wait to see what my fate is before diving into chips.

However, here's one last question:

Would there be any major issues with running a 93 chip with 91 gas?
And vice versa?

[bmwstephen]

if u run 93 with a 91 chip then no issue. running anything lower than that and you'll have engine knock. these ecus are primitive compared to modern cars and won't retard the timing (giving u lower power of course) when a lower fuel grade is detect it. if you put 93 into 91 then you'll just be pissing more money away because the ecu will just detonate it as if it were 91. good thing about Dinan is that if I were to live in an area with 93 octane, I can get a free reprogram under their 2 year warranty

[BrooklynMW]

Well it sounds like I can head back to NY, use 91 octane and not feel like I'm missing out on 93.

[LJ851]

if u run 93 with a 91 chip then no issue. running anything lower than that and you'll have engine knock. these ecus are primitive compared to modern cars and won't retard the timing (giving u lower power of course) when a lower fuel grade is detect it. if you put 93 into 91 then you'll just be pissing more money away because the ecu will just detonate it as if it were 91. good thing about Dinan is that if I were to live in an area with 93 octane, I can get a free reprogram under their 2 year warranty

ECUs do not detonate fuel.

[DmcL]

@ brooklynmw, hold it there dude. u got 1 thing wrong. where blefevre said more usable power on the dinan between 2-4.5k that is at FULL throttle only because dinan basically retain bone stock part throttle maps so u get no gains other than at full throttle. for a DD marks, or jim conforti, or active auto, etc. will give more usable power on the daily grind when ur not driving at full throttle. just wanted to clear that up before u go deciding on what to get.

[HakenTT]

DMCL would you confirm that checksum is not needed on 173 file?

[DmcL]

i think it depends on the year of the car/ecu or something. the EML doesnt come on in my 325i but my tune on someone elses car triggered the EML without the checksum corrected, it still ran as normal tho.

[Midnighttuning]

i think it depends on the year of the car/ecu or something. the EML doesnt come on in my 325i but my tune on someone elses car triggered the EML without the checksum corrected, it still ran as normal tho.

The 173 DME absolutely needs to have checksum corrected to maintain the integrity of the instructions inside the software on the chip, and yes the car will still run, but without the checksum corrected you will surely get a permanent CEL as well as loosing the diagnostics codes and stomp test function

[DmcL]

wow, and i thought this was going to be a reply with more bickering. good job, keep it up.

if u really want to be useful there are still some un-answered questions on e30tech in the motronic thread.