So I have this new ASM Monoblade bolted up to a fully ported LT4 intake sitting on my SR 396. It's extremely responsive compared to the 58mm but I'm struggling a little with the idle. The dyno tune air/fuel ratio is dead on where it needs to be, I've set the idle screw up to keep her around 11-1200rpm which it seems to do better with but still almost seems it wants to die pulling up to a light, it won't though just gets down to about 300rpm then it'll come back up around 900 or so.

It's getting a SuperVic here shortly and I wonder if I'll have the same issues, the LT4 intake is the only bottleneck possible in this engine and still not sure the idling issue would be due to the intake or possibly being caused by shaving off the IAC port entrance when you bore out the opening for the monoblade.

appreciate any tips.

 

Is your IAC counts maxed out in the tune?

 

Sense there's no IAC port to worry about, I'd try running nearest to "0" iac counts as possible maybe 5-10. You probably over that already though with your throttle blades opened up (to change idle instead a combo of IAC and throttle blade opening)...Hope you get it, I want to see what dyno numbers differences you see with that combo.

Edit: you do realize that you'll have to reprogram idle speed in the computer to get the PCM to try and idle the car. Then just set t-body opening to get the low IAC counts.....

 

No I didn't realize that to be totally honest, I'll be glad when I have the FAST pcm where I'll have to learn more than I really care to about tuning this puppy. When I install the SuperVic I don't understand what is used for the IAC? IntakeElbows has the elbow I plan to use, it has a MAP sensor port on the back, hopefully that setup will really wake up PEPE.


good question Tony I have no idea, Mike @GForce tuned it, I'll forward this on and ask him I guess.

 

is there still an idle air control motor?
you tuning this?

whats your air fuel ratio idle? with my fairly big cam i had to richen it to around 13.5-14.0, and add some timing.
helped alot

 

I don't have the chart with me here at work but the a/f is dead on from what was on the graph, this car runs a little rich but it puts out more power that way for whatever reason, if you try leaning it, she drops power.

I did not tune it, Mike @GForce dyno-tuned it.

 

I pretty much figured the reason Big cammed LT1 cars make more power a little richer is one bank is too lean. I have never double Widebanded a Big cam LT1 but looking at readings off narrow band, one bank is always leaner. In my case it's the drivers side. By about a half point I would say. So, I noted on the dyno that running about 12.5 to 1 (after Y-pipe, wideband) seems to give most horse power. At the drag strip it seems 12-12.5 gives best mile an hour. With cams like 847 (on strokers) and less you can get away with making most horse power around 13 to 1 (less variance from banks).

 

Very interesting diagnosis Jim. I ran the 847 with stock heads and forged pistons back couple years ago, put down 373 with a dynotune. The 847 is a baby cam for a stroker IMO so it was never even considered. I am running 12:5:1 compression and my cam is 110cl, .695 lift with 1.6s I believe and the duration is nuts, I forget the exact numbers but it's around 257/261 or somewhere close. I'll be glad when the SuperVic is done, pretty much had my fill of this LT4 intake, but it's brand new, fully ported throughout by LME and I'm selling it for like 5 bazillion dollars...lol...

Anywho I'll let you guys know how she does this Friday at the track.

 

Cool...good luck

I hope to have mine out for the 22-24 Sep races....Now that the fuel pump has been replaced and I have an actual second gear accelleration. It will be interesting to see if it's any faster, should be! (to bad the DA sucks up here now) On a side note...Ellis did get 1.52 60 foot with it, on those lack of fuel runs...."Got to love autos"

Oh, and also I run the same compression as you. AFR 210 heads done by LLoyd...Hyd roller cam though.

 

LLoyd does awesome work, I had LME max my 210s to flow .319, now if I can get my driving down right I might get into the 10s on motor, will find out Friday.

 

Man, I like that sig pic !!!!

 

i actually swapped my wide band to different sides and didnt see much if any of a change.


and BRETTINATOR i was talking about air fuel at ldle. did they do any idle, and part throttle tuning?

 

Well I learned from the tuner that they did adjust the idle a/f and the part throttle tuning best they could, issue with the mono is that the IAC is just not enough to compensate I guess. He recommended drilling about an 1/8" hole in the TB monoblade like on the LS1's to allow it to idle smoother. Kind of makes sense I guess because the SuperVic will not even use the IAC from what I've seen.

 

I got a red 93 for you but I may not be able to go to the track due to work

 

What size cam did you run? and on what LSA...

 

CamMotions custom grind, it's on a 110lsa, around 250 something 260 something duration w/around .690 something lift.

On a good note the problems fixed, one small 1/8" hole on the monoblade just above the IAC opening on the TB completely cured the problem, runs fantastic now!

 

234 243 600 600 112

i might be a few off on the duration but its around there somewhere.

 

have any pics, I may have to drill on my Monoblade.

 

if I wasn't getting ready for the track tonight I'd snap a pic but it's simple;
drill an 1/8" hole centerline of the monoblade on the bottom about a 1/4" up from the bottom of the blade just which will be above the IAC opening of the TB.

 

Sweet looking Lt1 hope u get in the 10's!