Mods in sig, just basic catback, cutout, CAI, Hooker Longtubes, but also 1.7 rockers and ported heads...and E85. Open Loop Tune

322 rwhp, 337 rwtq


The A/F was off on their dyno because I have a small leak where the y-pipe meets the catback pipe. My new LM1 was in my pass side collector, thus the reason I ran Open Loop. I read 11.6-11.8 A/F until the top when I read 12.0-12.2 (108% DC on the 30# SVO's).


Me on the dyno

 

nice, im expecting something similar. Bolt ons plus mild head and intake work.

 

cant tell from the graph, what did you rev the motor to?
And how much work is in those heads?

 

I got the heads from a guy offline, they were new and said he had $1400 in them as a "Stage 2" port job on them a few years back, just never put them on. Said didn't have the flow sheet any longer but said they were in the 260+ range intake and couldn't remember exhaust. I didn't have them flowed, but I did measure the intake ports at 195cc's and valves at 2.02 or 2.00/1.60. The exhaust ports had mild porting and the chambers had some mild work as well as milling. I also had them milled another .010 because I ended up accidentally nicking one of the head's surface and wanted to make sure there were no head gasket leaks. Also used Impala gaskets.

I have my limiter programmed at 6200 and revved to limiter, although my Datamaster log shows max RPM at 6150.

 

Did the guys at the dyno say the exhaust leak is costing you a few hp?

My heads dont have that much work, but the intake is done too and i have a 52mm tb.

I would be really happy with your numbers but i dont think my setup will produce it. But if it doesnt im going to switch to a LS lid and a aftermarket ign. so that should get me to my 330rwhp goal.

 

I always thought the cam was the LT1's biggest weak point, did not expect just a heads bolt on car to squeeze 80hp from the wheels. It is an m6 though so that helps alot I guess.

 

I would of done a cam too when I did the headgaskets but Im too afraid of spinning a bearing(118k). My buddy had a set of mildly worked heads and intake with titanium hardware that he sold me for 450 plus my heads and intake. (the hardware alone is 650)

I figured what the hell, the heads and intake should be worth a solid 15 hp so why not. Llyod or whoever does them next will have a head start.

 

With just CAI, cutout/catback, and MadZ28 tune I did 281/312, so I gained 41hp 26tq with just the heads, LT's, and 1.7RR. I think with my injectors hitting 85% at 4600 RPM and static at 5200 that more fuel, either by more psi or bigger injectors would have helped out, especially since power starts to level off at that point.

 

Kirby is experimenting with E85 as fuel. It should be interesting to see where he's at when the testing and tuning is done.

How's the mpg with the E85?

 

mpg's are worse with e85.

Interested to see what you would of put down with 30lbs injectors??

 

I was pretty impressed with the power you made, the stock cam is choking you.

You had a destinctive smell when you were making your pulls, smelled like whiskey mash

 

Oops, made a mistake on my A/F ratio! I was looking again online at some A/F for best power E85, and turns out I misread it. I though I was shooting for lambda of .80-.82 when I should have been shooting for E85 A/F ratio of 8.0-8.2. Basically meaning that my gas A/F reading should have been 12.1-12.2 anyway. So I need to go back and lean out my PE vs RPM tables instead of richen, which is what I did on the dyno runs. That should give me a little more room on the injectors, although they will probably still go static, just probably at a higher RPM, about 100 or so I figure.

 

Lamda .82 is 12 a/f ratio showing on gasoline, and it is about 8 a/f ratio for e85. I would lean out the readings that were in the 11.6 and 11.8 range though. Not sure where the brain fart came from, i told you exactly what to look for over in the pcm section. E85 is pretty forgiving though, much more so than gasoline. I tried to vary mine in increments of .25 for a/f ratio at the track from max rich to max lean best power. It made very small differences but seemed to favor 8:1 over anything else.

 

Since my injectors are maxed, I guess I need to either find an adjustable fuel pressure regulator, or some 42# injectors to get the WOT in line. Would I benefit from a bigger TB as well? Maybe a used 52 or 58mm? My MAP value goes down to around 95 at the higher RPM's, so I assume that the bigger TB would make up some of this restriction, allowing for maybe another 5 hp or so? If it would get me over 330 rwhp with correct (and under 85% duty cycle) fueling and more airflow I would say it would be worth it to me.

 

Kirby look at what datamaster is reporting atmospheric pressure at, if all you got is 95kpa then you're in good shape if wot map goes to 95kpa wide open. I have a 52mm tb on mine from lpe and with the smooth bellows i have no restriction showing at all according to the map and a vac gauge. Dont forget though, the map reading is relative to everything in the intake tract including the elbow and the filter on the end. Sometimes on the dyno I pull the filter and everything in front of the maf if I think its suspect and I dont have zero vacuum at peak hp.

My recomendation on the injectors would be to hit the 30lbers with more fuel pressure if you have a pretty good fuel pump. going to 60psi will get you 35.2pph. In any case I like the high fuel pressures, I have read some sae papers to the effect that the higher pressure gives a better droplet size and delivery etc. It comes as a stock setting on all the newer engines like the lsx stuff, so theres gotta be a little something to it. Be very careful which adjustable regulator you pick if you go that route, alot of them are just junk.