Can you turn a Mass air flow tpi into a speed density tpi what needs changed mine is a 89 and I want to make it speed density for a 91 can it be done? What needs to be done to complete it other than the ecm and does the wiring harness need to be changed?
I have a 89 5.7L that I'm installing in a 91 Camaro and I'm running into a problem with the vss because the 89 engine harness is not equiped with it so I need a speed density system and I want to try to change over wilth minimal costs of course. The two systems look the same other than the map sensor so can I just add a map sensor to my system and a new harness and ecm will this complete the set up?
Thanks

 

Sure you can, here is a thread on this subject.


https://www.thirdgen.org/techbb2/sho...hreadid=127238

 

Actually, converting to SD is cheaper than buying a new MAF.

You can completely repin the harness from a MAF 165 to SD 7730 - all you need to do is snaffle the connectors from a wrecking yard. Do a search on "Mike Davis", he has a web site that lists the pins from the 165 and where they go on a 7730.

The can actually reuse the VSS from your 89 by altering the MAG Switch in the SD memcal - it supports both. And you can reuse the wiring going to the MAF and use it for the MAP Sensor.

Lastly, do some searchs on the Knock Sensor. You can reuse the 89s knock sensor with a minor modification - or just buy a knock sensor for an SD car.

 

I just recently converted my 87 TPI setup to a speed density 91 setup. I used the document mentioned above. It's pretty easy to do. You should be able to do it in a weekend (or less).

 

Just throwing in my vote for SD

 

Absolutely! I was able to remove the two MAF relays, ESC module, and a few other things (including smog equipment) during my SD conversion. My only complaint is that the ECM will not fit up into my dash in my S-10. The plugs now mount on the other side of the ECM.

To go along with what Glenn said, the conversion costs nearly nothing after you sell your existing MAF stuff (165 ECM, MAF sensor, ESC module, MAF Power relay, MAF Burn-Off relay, and Knock Sensor).

 

What are some benefits of SD over MAF? What are all the components I would need for the swap? And would my application specific Hypertech chip become useless? Thanks in advance.

 

here is another problem with what I'm doing I have a 89 harness that is maf and my car is a 91 which also was a v6 mpi originally but I'm installing a 89 5.7L tpi and a 5 speed but anyway I also need to incorporate a vss in this old harness that is not equiped for one is that possible? this is main reason for me changing to sd so I get the new harness with the proper wires so my speedo will work.
Thanks agian everyone who is repling so far has been very helpful.
Bryan

 

tpiroc - to answer your questions....in my opinion the major benefit of speed density was to remove the MAF sensor and eliminate a lot of wiring. I had also heard that speed density was better from prom tuning.

Here's what you will get rid of from the mass air setup: 165 ECM, MAF sensor, ESC (electronic spark control) module, MAF Power relay, MAF Burn-Off relay, and Knock Sensor

Here's what you need for the conversion: 730 ECM, MAP sensor, Knock Sensor, and a new memcal (that's where the prom is located).

You can not use your Hypertech prom with a speed density car. If you do a bit of searching on the DIY/PROM forum you'll understand that a generic aftermarket prom is hardly worthwhile for your vehicle. Your best bet is to burn your own proms.

maxgforce - about your harnesses....the 89 TPI harness you have can be easily converted to speed density...I don't know if it is a direct plug in to your 91 fuse box. It may be...but I don't know.

The speed density ECM (aka 730) can either take a VSS signal directly from the VSS or can take a signal from the VSS Buffer. The prom will be expecting a signal directly from the VSS. In my vehicle I had to change the setting in the prom so I could use a VSS Buffer signal. My VSS sends a signal to the VSS Buffer, which sends a signal to my ECM and speedometer.

 

This question has been asked a million times and with a million answers. I suggest doing some searches and let yourself be the judge. I've worked and tuned both and, in all honesty, you can obtain equally good results with both.

Yes, there is the 255 gm/sec limitation in the reported airflow of the MAF, but you just add more fuel via the Power Enrichment Tables. A WB O2 sensor is a great help here.

SD does require more tuning for the VE Tables. It takes a little time, but it is definitely not hard. But, I've spent far more time playing/tuning with my Spark Tables than the VE tables - which you would have to do with either.

Some will argue that SD gives you a "cleaner shot" to the intake by avoiding the restriction of the MAF. And others will show some very fast MAF cars and say "what restriction".

My personal feeling is that if you got a perfectly good working MAF system, stick with it unless you start to experience driveabiltity issues. If the MAF takes a dump, then you may want to consider swapping as the cost can be cheaper. I can find a 7730 ECM at virtually any junk yard. The 7730 was used in a ton of GM cars that used the 3.1 V6 in the early 90s.

Conversely, 165 ECMs are getting much harder to find as they only came in F-bodies and Y-bodies in 1986-1989. That would be another reason to consider a swap if the only choice you have to find a 165 ECM is a brand new unit from GM vs a used 7730 from a junk yard.

 

Thank you for your replies; yes I had done a search prior to asking the question however the results I found weren't entirely conclusive. Thanks again.