I know that most of you believe that if you upgrade your motor for performance, you shouldn't care much about your gas mileage. Well, Since I installed an HSR, I had to remove the AIR, and the EGR system, because they aren't compatable. Since I've done this, I've noticed that my MPG has decreased 3-4 mpg on the highway and 3-6 mpg around town. I was wondering if i installed an MSD ignition box, would it help my MPG return to the same MPG before the HSR install? I figure that a hotter spark would burn up the fuel better, leading to better mpg's. Afterall, part of the emissions system was meant to capture unburnt fuel...

 

Well I think the best combination gives performance with economy. Now my combination isn't a gas saver (3.70 gear) but I do tune for ecomomy. Removing the items you noted shouldn't in itself kill mileage. A "hotter" spark via MSD or other high capacity ignition should help but my guess is it is in your tune. Everything must be optimised for your new combo. Are you tuning your program? If not, get into it as that is the only way I know of to get where you want to go. Unless you have a unique combination I don't believe the HSR will hurt your torque in the lower RPMs.

 

I'm still using a stock tune while recieving the bad gas mileage. So you are suggesting a computer tune would help? I was looking at getting a ostrich 2.0. Then from there, start reading up the changes I would have to make on the computer.

 

Yes I am suggesting starting to tune your program. It is a little involved to get going but should be worth the effort. Read the stickys in the prom section. I am using Tunerpro rt v5 with a burn 1 & cable. The realtime programming hardware should be an advantage as well. Good luck and happy tuning!

 

I just bought an autoprom kit from moates, so i'll see if I can get some sort of eco and performance tune made. Thanks for the help.

 

https://www.thirdgen.org/forums/post...137-post4.html

https://www.thirdgen.org/forums/post...872-post2.html

 

Thanks for the post. I finally got the eco and performance tune I was looking for. For the performance tune I added 2 degrees of timing for idle and cruise. I Added 4 degrees from 2000 to 2600 at WOT and added 6 degrees of timing from 2800-4400rpms at WOT, then dropped backed at 4800. For the Eco, I added the highway mode feature to kick in at 1300 rpm at 50mph. Highway mode is set to add 2 degrees of spark with a target AFR of 16.0. So far my highway travel mileage is better, but my city mileage is about the same. I'm pretty happy with the tune so far. I will have to get a wideband gauge to fine tune the current tune. I have another question, can I still use 89 octane fuel for normal driving with what I did?

 

how was tuning with the moates kit ?

 

I bought the autoprom kit from moates. It's a chip burner, and a live tuner.

 

yea im on the website now lol. i want to learn how to tune myself been reading alot about it
how do switch between your different tune?

is it this one ?
http://www.moates.net/apu1-autoprom-...b-version.html

 

I learned in 2 days on my own. Craig Moates has videos on youtube showing you how to do everything. My first day I was tuning, I tried a bin file called ARAP, it scared the crap out of me. I was pealing out everywhere at half throttle. Bin files are the tune that your computer follows. I couldn't use that ARAP because I don't have aluminum heads to absorb the heat, plus my knock sensor kept on retarding my timing. The best is just to modify your stock bin, then compare it to other high performance bin. When you tune, you just have to watch your air/fuel ratio. You want a 13 or below afr when figuring out the best WOT tune. I don't have a wideband gauge to properly moniter the WOT afr accuratly, so I am guessing right now by watching my knock counts. There are so many resources here to use as guidance.

 

I bought this seperately with the package. You'll need this adaptor to run live tuning.
http://www.moates.net/gp1-package-gm...h-2-chips.html
You can run a computer if you want to live tune it and switch it all the time. I found it easier to just burn two chips. I have my current chip in which I call the eco performance chip. Then I have another chip sitting in my console box incase I want complete all around performance.

 

where you get the bin from ?

did you find out how much mpg you gain?

 

the bin files come from the website tunerpro. You just have to moniter your your miles and how much gas you put in at the pump. The program doesn't moniter mpg, wish it could.

 

lol ok makes since .. i know that the program doesnt moniter that.. just woundering have check to see if your getting more milage

you should be fine with 89 octane with normal driving unless you lowered the compression ratio
but as you get into more aggressive tune where knock becomes a issue then higher octane would be needed for the timing required but L98 have low CR think its 9.5 also the temp of you engine helps also and plays in to the tune a lower temp you have less issues and can be more aggresive with tune where as a hotter engine more conservative

 

I'll have to get back to you on the mpg part. I can get exact mpg numbers in a week. I drive 70 miles a day 65 of them are highway.

 

Burnout91 has done EGR on his HSR. You're not going to get that much mileage back from ignition unless the ignition was faulty. So to answer your bolded question, no.

AIR doesn't impact mileage.

 

I just filled up. I got an average of 19.9 mpg on 8.5 gallons. That was 40% city 60% highway driving with the AC on. I will post my next results which should be 90% highway driving.

 

That should be encouraging. My window sticker says 17/25 when it was new so you aren't too far off from stock mileage. Get an average over 3-4 tankfulls to see the full picture. Sometimes a single fillup can be off a little if you filled it up a little less/more. I am recording mine now so you should really have something to feel good about when my numbers come in lol,

 

not bad did you do any other tunning

 

Turning on highway mode has helped a lot. I have the fans kicking on early, so the car never goes over 215 degrees. I advanced the whole spark table 2 degrees at idle and cruise. I set the target AFR for highway mode at 16, then it adds 3 degrees of advance over the spark table when it kicks in. I need to give more results, I am using the AC again on the highway due to the 90+ degree days here. AC kills the mileage, but when I'm not using it, the gas gauge does go down less than it used to.

 

lol its crazy hot over here in California also especially when driving thru the high desert 110 was temp last time but its good to know that your seeing improvements
good job

 

FYI First MPG check netted 14.8 combined driving. Still doing some tuning work so not optimized and no HWY mode yet. But I think it is in the ballpark. Not to say I'm "happy" with it but a 3.70 gear hotrod getting ~15MPG isn't too bad. Before I had overdrive trannys +10MPG was ok...

 

Thats not bad for 3.70 gears. I'd get a 14.8 average if I had a heavy foot (when I first installed the hsr setup). The best I've gotten so far is an average of 22mpg with the ac on and highway mode on. If I am able to get an average over 25 mpg this fall, I will post again. I figure since I won't be using the ac then, mileage will go up. I will say, that messing with the tune helped get my mileage back to where it was, and also, I don't have the heavy new mod foot anymore.

 

EGR and AIR removal had no effect on my car... I replaced my 305 with a 350, with a heavy, heavy foot and blocked off the EGR and removed AIR. Runs like a dreeeaaammmm....

 

Last two MPG checks were over 15.2 MPG combined city/hwy. Again this is with 3.70 gear and no hwy mode. I am switching back to 3.27 gear and will let you know if that nets any improvement. I suspect it will but I am not expecting a signifigant overall change. As it is now the engine just loafs down the road at ~50-70 LV8. Going to a higher gear should put it into a higher load operation, so I expect to gain a larger improvement during highway operation as compared to in town. The trans will probably just end up in 4th instead of 5th in town. But we'll see...

 

Agreed. 90% of applications where people have msd dont really need them.

keep tuning..you could spend hundreds of hours learnign/perfecting it.

 

Where the MSD can help is igniting lean mixtures that would normally be too lean. Sometimes it will allow you to slightly broaden the range on the lean AFR side. This will show itself more on high compression/high boost apps. If you are already lighting the fire reliably, it wont burn more efficiently by trying to light it a second time.

Also keep in mind that an MSD really only does multiple strike's at lower rpm's. Although it is still has a nice strong CD spark at any RPM.

 

I was wondering if your car is a maf car or map? I have a 87 Formula with MAF and I'm thinking about getting a system that I can tune for my application. I currently have a custom chip with the MAF and major modifications to the engine and the car runs great. Just think I maybe leaving something on the table with a programmable system