question about tuning and a 111+2 cam
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question about tuning and a 111+2 cam
I have a Predator Z speced cam that is a 230/230 598/612 on a 111+2. I also have prc stage 2.5 5.3 heads and fast 92/92. I also have kind of large injectors they are flow matched 42 lb injectors. The question is after the install and they dyno tuned the car its kind of a bitch to start and keep it idleing when it is cold. Once the car warms up for a minute or two it will idle fine.I had to give it a little bit of gas and play with it to actually keep it running. Is this normal or some thing that can be solved with the tuning? The car almost acts like it is flooding out when you first start it. I had new NGK tr6s installed along with new plugs wires.
I also noticed the car idles at like 950-1000 rpms is this normal or a little high? I have had two other head and cam cars and both of those idled some where between 850 and 900.
I also noticed the car idles at like 950-1000 rpms is this normal or a little high? I have had two other head and cam cars and both of those idled some where between 850 and 900.
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Yeah but you have a massive cam compared to mine my cam is a 230/230 598/612. The lobe seperation is low on mine though. I have also noticed if I make a reasonably hard stop (not really slamming on the brakes but a quick stop) the idle will start surgeing and somtimes the car stalls or dies. Then when I restart it it will be idled up high.
Last edited by bigfatls6; 01-26-2009 at 05:50 AM.
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I would see if they tuned the effective area for the larger intake/TB. The timing usually needs to be increased at the lower rpms and blended so the idle in park/drive tables blend in with the high/low octane tables. If there's a big drop or increase between these tables, it'll swing or hunt to find itself. Getting the VE table dialed in (I bet it's not) makes a big difference in idle and throttle transition stability.
The cold start problem is likely from having too much fuel in the lower rpms in the OL fuel table.
You almost need to tune it yourself or find an individual tuner like Patrick G to dial the tune in. It just takes too much time for most shops to get it perfect. Some have the knowledge, but most can't spend that amount of time to get it spot on. It really is time consuming.
The cold start problem is likely from having too much fuel in the lower rpms in the OL fuel table.
You almost need to tune it yourself or find an individual tuner like Patrick G to dial the tune in. It just takes too much time for most shops to get it perfect. Some have the knowledge, but most can't spend that amount of time to get it spot on. It really is time consuming.
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I would see if they tuned the effective area for the larger intake/TB. The timing usually needs to be increased at the lower rpms and blended so the idle in park/drive tables blend in with the high/low octane tables. If there's a big drop or increase between these tables, it'll swing or hunt to find itself. Getting the VE table dialed in (I bet it's not) makes a big difference in idle and throttle transition stability.
The cold start problem is likely from having too much fuel in the lower rpms in the OL fuel table.
You almost need to tune it yourself or find an individual tuner like Patrick G to dial the tune in. It just takes too much time for most shops to get it perfect. Some have the knowledge, but most can't spend that amount of time to get it spot on. It really is time consuming.
The cold start problem is likely from having too much fuel in the lower rpms in the OL fuel table.
You almost need to tune it yourself or find an individual tuner like Patrick G to dial the tune in. It just takes too much time for most shops to get it perfect. Some have the knowledge, but most can't spend that amount of time to get it spot on. It really is time consuming.
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I would see if they tuned the effective area for the larger intake/TB. The timing usually needs to be increased at the lower rpms and blended so the idle in park/drive tables blend in with the high/low octane tables. If there's a big drop or increase between these tables, it'll swing or hunt to find itself. Getting the VE table dialed in (I bet it's not) makes a big difference in idle and throttle transition stability.
The cold start problem is likely from having too much fuel in the lower rpms in the OL fuel table.
You almost need to tune it yourself or find an individual tuner like Patrick G to dial the tune in. It just takes too much time for most shops to get it perfect. Some have the knowledge, but most can't spend that amount of time to get it spot on. It really is time consuming.
The cold start problem is likely from having too much fuel in the lower rpms in the OL fuel table.
You almost need to tune it yourself or find an individual tuner like Patrick G to dial the tune in. It just takes too much time for most shops to get it perfect. Some have the knowledge, but most can't spend that amount of time to get it spot on. It really is time consuming.
About the idle speed, I had a H/C (bigger spec'd cam that what you have in your car) LT1 car that I could idle at 850 ish and be fine. LS1's, from what I've seen, need to idle a little higher idle with an aftermarket cam. I'd say 950-1000 rpm is probably where you want it.
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Exactly. The OP needs to realize that taking your car to a shop and throwing it on a dyno for a "dyno tune" does nothing for cold start up and regular driving. I've seen a lot of tuners just tune the 90-100 kPa from 3,000 to 7,000 rpm part of the timing table, adjust the WOT fueling, and then be done with it. No work with the VE tables, no adjustments of idle timing, no driving and logging the car, no part throttle MAF table adjustments, etc. Then, they charge you $400, and people are satisfied because their car put down XXX amount of horsepower, but it drives like dick at part throttle. Doing all of the necessary tuning requires a street tune and many hours to dial it in completely.
About the idle speed, I had a H/C (bigger spec'd cam that what you have in your car) LT1 car that I could idle at 850 ish and be fine. LS1's, from what I've seen, need to idle a little higher idle with an aftermarket cam. I'd say 950-1000 rpm is probably where you want it.
About the idle speed, I had a H/C (bigger spec'd cam that what you have in your car) LT1 car that I could idle at 850 ish and be fine. LS1's, from what I've seen, need to idle a little higher idle with an aftermarket cam. I'd say 950-1000 rpm is probably where you want it.
#14
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I had LMR do my new 445s base tune on the dyno to make sure it would idle and get the AFR safe. Aside from that, I do my own tuning for the reasons you described in the first post. It was a huge learning curve, especially since I'm computer illiterate.lol. Now I'm tuning all 4 of my personal vehicles, because drivability is very important to me.
I've learned everything I needed right here and on HPTuners.com. I got quite a bit of help from the guys here at LS1tech.
It's nice not have to rely on someone else to tune for you especially if you are constantly making modifications to the car. On the other hand, if you don't have the time or desire to take the time to learn it, having a good tuner near you that knows his stuff is great to have.
It is very frustrating to have a car that won't idle stable and dies when it wants. Hopefully he'll get you fixed up. It sounds like your tuner is patient and willing to take the time to get it right.
G/L
I've learned everything I needed right here and on HPTuners.com. I got quite a bit of help from the guys here at LS1tech.
It's nice not have to rely on someone else to tune for you especially if you are constantly making modifications to the car. On the other hand, if you don't have the time or desire to take the time to learn it, having a good tuner near you that knows his stuff is great to have.
It is very frustrating to have a car that won't idle stable and dies when it wants. Hopefully he'll get you fixed up. It sounds like your tuner is patient and willing to take the time to get it right.
G/L
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I had LMR do my new 445s base tune on the dyno to make sure it would idle and get the AFR safe. Aside from that, I do my own tuning for the reasons you described in the first post. It was a huge learning curve, especially since I'm computer illiterate.lol. Now I'm tuning all 4 of my personal vehicles, because drivability is very important to me.
I've learned everything I needed right here and on HPTuners.com. I got quite a bit of help from the guys here at LS1tech.
It's nice not have to rely on someone else to tune for you especially if you are constantly making modifications to the car. On the other hand, if you don't have the time or desire to take the time to learn it, having a good tuner near you that knows his stuff is great to have.
It is very frustrating to have a car that won't idle stable and dies when it wants. Hopefully he'll get you fixed up. It sounds like your tuner is patient and willing to take the time to get it right.
G/L
I've learned everything I needed right here and on HPTuners.com. I got quite a bit of help from the guys here at LS1tech.
It's nice not have to rely on someone else to tune for you especially if you are constantly making modifications to the car. On the other hand, if you don't have the time or desire to take the time to learn it, having a good tuner near you that knows his stuff is great to have.
It is very frustrating to have a car that won't idle stable and dies when it wants. Hopefully he'll get you fixed up. It sounds like your tuner is patient and willing to take the time to get it right.
G/L
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I'm running a 228/232 111 +4 I idle right around 900 rpm starts first try. Sounds like your raf table may not be setup right and may need some more timing. I'm also running 42lb injectors.
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It's really not that hard to do with the right tools and experience...if all systems are working properly- leaks up top or down below often get misdiagnosed as poor tuning
My setup,
MS4 / PRC Stg 2.5 5.3 heads idling @ 750rpms.
My setup,
MS4 / PRC Stg 2.5 5.3 heads idling @ 750rpms.
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I have also noticed with the new setup its getting some terible gas mileage. It only has about 65 miles on this tank of gas and its already down to a half tank. I know its not going to get great mileage but damn. My old heads and cam car with red top 30lb injector would still get around 15-16 mpg. Is this because of the 42lb injectors or what?