New contributor....A couple questions about ROM tuning

FastNX · 02-28-2005, 07:21 PM

Hey guys, it feels good to finally become a contributor. Anyways, I am very interested in this ROM tuning, but know next to nothing about computer chips, how they work, and how to modify them. Basically I would like a question answered about their use to tune.

I have a race car that has a fairly wild N/A engine, and I have ruled out JWT, since I hear about problems with lean air/fuel mixtures when using high overlap cams and the Gen 6 header. I have narrowed it down to having the maps tuned via a Tectom program, and this.

Now for my questions.
With the ROM editor programs, what can be edited? Fuel and timing, knock sensor and rev limit? How easy is this software to use? Could it be tuned by someone who is an expert at tuning, but has not used this program? What would I have to do to have the computer ready to be tuned? Send my ECU to Calum and have a lappy?

Basically what it boils down to is that the tuner wants $750 Canadian (roughly 600US) to add the tectom chip to the stock computer, plus $200 per hour to tune. I realize that I'm going to have to pay for tuning either way, but would this be a cost effective and somewhat simple to use alternative to the tectom option?

Calum · 02-28-2005, 07:44 PM

Everything you listed can easily be edited. Rom Edit, Live Edit, a copy of excel and a decent hex editor are pretty decent tools for tuning for the time being. That covers everything you want to do, but like anything else theres a learning curve.

Send me an ecu, $100 (or $750CAN, I wouldn't turn it down

) and your good to go. Oh, and buy a rom burner.

Here's the one problem for your case. Right now tuning it while your driving is covered, but tuning the idle still has a long way to go. That means improving the idle beyond what the stock ecu does is probably not going to happen in the near future.

P.S., you need a consult box too. Consider that a mandatory item, just like a wideband. Tuning without one is foolish, especially considering the price.

So $100 for the ecu, $85 for the burner, and $50? for the consult box, thats about the minimum cost of entry.

JayLew · 02-28-2005, 09:07 PM

Quote:

Originally Posted by Calum

P.S., you need a consult box too. Consider that a mandatory item, just like a wideband. Tuning without one is foolish, especially considering the price.

On the subject of widebands. I found one on atpturbo.com that sells for $76. Its a 5 wire. Is there a specific wideband that works best for out cars/ecu's?

My understanding of widebands are that they are hooked directly up to a AF guage to give you an accurate AF ratio....or are they more complicated than that?

Calum · 02-28-2005, 09:26 PM

Edit: Looked at ATP's website. Thats just the sensor. You can buy that from any VW dealer. Theres a lot more to a wideband then the sensor. Unlike narrow band O2 sensors (or lots of other sensors) they require feedback to operate. In other words, its worthless without a controller, and thats what your really paying for when you buy a wideband.

More complicated than that. Waaay more complicated. That can't be a wideband, $76 wouldn't even pay for a sensor.

I've got an Innovative LM-1, ~$300 street. They're making a lower cost version soon with less features, but get the LM-1. Thats about as cheap as it gets. The LM-1 is pretty good, I've got some nit picks but nothing major. The same group that did the MegaSquirt has a wideband project listed on their site. I think they've got the technology really nailed, I'm really impressed with their understanding (of the wideband). Whenever that reaches completion I think that will be worth looking into.

FastNX · 02-28-2005, 09:38 PM

Thanks for the info. What is the consult box, and what is its function? And where would I get one?

Calum · 02-28-2005, 09:59 PM

A consult box is a device that lets your laptop talk to the ecu. See the thread about the new version of CalumSult on why this is useful. For rom tuning the biggest asset is it lets you monitor and record every sensor and some of the calculated values (really really useful), but you can also extract the rom from the ecu (not useful in your case), perform various tests on the ecu (like put it into timing mode with the click of a mouse, very cool) and some other stuff. If you've ever read an FSM you've seens sections on the Nissan CONSULT too. Its the little "scanner" that dealerships have to "test" your car. Basically we're using our PCs to emulate its functions, and more.

Uh, there are various sources that sell them on the web, mostly in aus or NZ. I build and sold these for a while too, but it was too labor intensive vs the profit for me, but I've still been building a stead stream for people on the side. There has been DIY kits sold in the US, but the supply of those seems to have dried up so I went ahead and designed a board for this purpose. They came in today, I hope to have them tested and ready to sell about the end of next week.

FastNX · 02-28-2005, 10:05 PM

dang, I have a decision to make quickly, I don't think I'll be getting much sound sleep tonight.

So basically I could buy the consult box from you as well. What it boils down to for me is is it worth saving the money to possibly not being able to have the computer soldered up in time and figured out in time for the first race of the season (April 30). Then again, I could leave the (mostly stock) engine in the car for the first race and worry about this stuff later on

FastNX · 03-01-2005, 03:20 PM

Alright, my brother has referred me to someone who can solder extremely well (I beleive he is a computer engineer and he has done soldering in automotive computer applications before) so I may just get you to send me the chip and consult box. Please let me know when you have the consult boxes ready to go, hopefully I will have made my decision by then.

Keep up the great work Calum!!!

exxd · 03-01-2005, 03:53 PM

Quote:

Originally Posted by FastNX

Alright, my brother has referred me to someone who can solder extremely well (I beleive he is a computer engineer and he has done soldering in automotive computer applications before) so I may just get you to send me the chip and consult box. Please let me know when you have the consult boxes ready to go, hopefully I will have made my decision by then.

Keep up the great work Calum!!!

The chip is really a daughterboard and two chips, Your not removing an existing chip and replacing it, Check out the great writeup calum did.

Goodluck!!
-Nate

FastNX · 03-02-2005, 10:25 PM

I forwarded the link to the guy who is doing the soldering and he said he can do it no problem.

Calum · 03-03-2005, 10:33 AM

I charge the same for me to do the board or you to do the board. I highly advise you take advantage of that and let me do it. If you do it and it doesn't work I will charge you if you want me to fix it. That said, have fun, less work for me.