RMcElwee - 350 HP LS1 Miata (need help with tuning / EFILIVE)

[rmcelwee]

First day, first post - My name is Robert McElwee and I live in Moncks Corner, SC. I'm not a big gearhead (only a shade tree mechanic) but I've always wanted to build a V8 Miata. I found one that was already built with an LS1 and T56 from a 2000 Trans Am (springs and cam are the only upgrades) and couldn't pass up the price. I was not happy that I didn't get to build it myself but I have purchased a nicer looking Miata (the original one is completely trashed) and will swap everything over so I guess it is kind of the same thing. I put it on the dyno the other day (graph below) and it is running a little lean. I was getting ready to get it tuned and a friend told me that I should just do it myself with EFILIVE since I am only wanting to fix a lean spot. I've done some laptop tuning before on a turbo miata with a full replacement ECU so this isn't a huge issue for me. The only thing is I am unfamiliar with the software/cables to get this thing hooked up and searching on the net has been a nightmare. Anyone here that can help me? Thanks!

http://www.lightweightmiata.com/v8/dyno/dyno02.JPG

Ugly car:
http://www.lightweightmiata.com/sleepy01.JPG

Nicer looking donor car (hardtop Miata):
http://www.lightweightmiata.com/v8/donor/donor02.JPG

[DolSVT00]

Welcome.

There's some knowledgeable guys on here with good experience using EFI live and HP tuners.

Those seem to be the big preference when it comes to the LS biased motors, I'm sure Zach, Bad Bob and a few others could get you pointed in the right direction.

[98nbmz]

Swap in an obd2 port, prob get it from a junk yard this will allow you to use efi live, hp tuners, etc..

[slowgreen99]

Swap in an obd2 port, prob get it from a junk yard this will allow you to use efi live, hp tuners, etc..

IF the car is wired for the ls swap, it should have an OBD2 port correct?

[98nbmz]

IF the car is wired for the ls swap, it should have an OBD2 port correct?

Not if he used the miata harness

[Sean]

Welcome. Looks to be a fun project. A v8 Miata sounds like a blast.

[Matts94Z28]

Welcome. Is this the same car that had a big build thread on LS1tech a while back?

[bwelch]

bad ass! even though I cant fit in it

[red99pony]

what are you going to do about the piece sticking through the hood?

[BAD BOB]

efilive just plugs into the obd2 port then using a wideband you have to figure how to wire your one into the efilive box. all pretty simple

[Mike]

bad ass! even though I cant fit in it

x2

[snakeplissken]

x2

http://www.tvacres.com/images/grape_ape.jpg

[minytrker]

Give JP a call 843.608.8579 http://lsxtuningandperformance.com/ He uses EFI Live and does tuning.

[rmcelwee]

IF the car is wired for the ls swap, it should have an OBD2 port correct?

Yes, it has the Miata ECU and wiring harness but has a GM ECU with OBDII port wired to the engine. I currently get my MPH and water temp through the OBDII port (Scangauge).

[rmcelwee]

Welcome. Is this the same car that had a big build thread on LS1tech a while back?

The PO tried to sell it there a while back. I don't think he ever did a build thread on it. If he did, I'd like to see it since he really wasn't very helpful with many details on how the car was put together.

[rmcelwee]

what are you going to do about the piece sticking through the hood?

When I swap the engine into the new car I will buy another 90 degree bend (or whatever it needs) to get it back under the hood. The hood is not worth $10 on a good day so I understand why he didn't feel any remorse about cutting it up. Still, I think it may be the best feature on the car. It definitely gets more reaction than anything else.

"I've got a V8 Miata."
"Oh yeah?"
"It has a hole cut in the hood."
"DAMN! That thing must be fast!"

[Carlrx7]

i wanted to do the same for the rx7, but i didn't want to go backwards.

i have hptuners, and if it has an ls1 pcm and harness, i also have a tuning wideband. gimme some beer and pay for the credits.

to me, that lean spot looks like your either out of injector or the pump is going poop.

[98nbmz]

i wanted to do the same for the rx7, but i didn't want to go backwards.

i have hptuners, and if it has an ls1 pcm and harness, i also have a tuning wideband. gimme some beer and pay for the credits.

to me, that lean spot looks like your either out of injector or the pump is going poop.
Stock ls1injectors are good for over 400 HP doubt it would be them. Could be the miata pump though. Using the stocm miata or walbro?

[rmcelwee]

Stock ls1injectors are good for over 400 HP doubt it would be them. Could be the miata pump though. Using the stocm miata or walbro?

It is a walboro255.

[rmcelwee]

i wanted to do the same for the rx7, but i didn't want to go backwards.

i have hptuners, and if it has an ls1 pcm and harness, i also have a tuning wideband. gimme some beer and pay for the credits.

to me, that lean spot looks like your either out of injector or the pump is going poop.

I might get with you sometime on the tuning. Should be pretty easy to just add a little fuel here and there (or at least it has been on the other brand ECUs I've tuned).

[04ctd]

It is a walboro255.

what size lines?

filter new, or used?

AFPR or stock FPR? pressure gauge & readings?

[ElecTech]

Stock ls1injectors are good for over 400 HP doubt it would be them. Could be the miata pump though. Using the stocm miata or walbro?

Not true. To the crank, but not to the wheels. I have seen the stock injectors over 90% with just a cold air intake and headers. They may not go lean, but they are being overstressed.

[Jeff@HHP]

First day, first post - My name is Robert McElwee and I live in Moncks Corner, SC. I'm not a big gearhead (only a shade tree mechanic) but I've always wanted to build a V8 Miata. I found one that was already built with an LS1 and T56 from a 2000 Trans Am (springs and cam are the only upgrades) and couldn't pass up the price. I was not happy that I didn't get to build it myself but I have purchased a nicer looking Miata (the original one is completely trashed) and will swap everything over so I guess it is kind of the same thing. I put it on the dyno the other day (graph below) and it is running a little lean. I was getting ready to get it tuned and a friend told me that I should just do it myself with EFILIVE since I am only wanting to fix a lean spot. I've done some laptop tuning before on a turbo miata with a full replacement ECU so this isn't a huge issue for me. The only thing is I am unfamiliar with the software/cables to get this thing hooked up and searching on the net has been a nightmare. Anyone here that can help me? Thanks!



Robert,
Are you still coming in Saturday?

[98nbmz]

[/LIST][/INDENT]Not true. To the crank, but not to the wheels. I have seen the stock injectors over 90% with just a cold air intake and headers. They may not go lean, but they are being overstressed.

I worded that wrong really. Most people don't ditch stockers with a small/mid size cam. My previous car h/c ls1 made 440 rwhp on stock injectors, 110th duty cycle yes, lean spots no. I was just saying I doubt the injectors themselves are the problem for the lean spot.
Let me know if you make it to the shop today ill stop by and lend a hand

[Carlrx7]

I might get with you sometime on the tuning. Should be pretty easy to just add a little fuel here and there (or at least it has been on the other brand ECUs I've tuned).

you think its easy until you come across a tune that has been royaly hacked up.

[rmcelwee]

you think its easy until you come across a tune that has been royaly hacked up.

That's pretty much the same with everything. I had a Miata "professionally tuned" one time. Took 4 hours and before I left I loaded my original tune back to the ECU. I've been pretty leery of letting people tune my cars after that but I am going to give HHP a try tomorrow. Hopefully I'll have a smile on my face afterwards.

[rmcelwee]

Well, I took the car to HHP today and they tuned out the lean spot. They said the injectors were running around 90% duty cycle so that is something I will keep in mind if I ever upgrade anything (doubtful - car is strong enough).

The new tune vs lean tune:

http://www.lightweightmiata.com/misc/sleepydynotuned.jpg