Turbo LT1 guys in here
04-18-2011, 09:05 PM
#1
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Turbo LT1 guys in here How many of you have converted to a efi connection 24x system? I would love to do this but it looks really expensive. How hard was it to tune a high horsepower boosted LT1 with a factory computer? I am looking to make 700+ hp and I am not sure if I can get there with a factory ECM. Any input would be great. Thanks.
04-18-2011, 09:43 PM
#2
Problem with the stock PCM is you have to scale your map tables to a 2 (or 3) bar map and you lose resolution on your fine tuning. An aftermarket ECM is the only way to go for the power you are looking for IMO. As it is the stock PCM doesn't have the greatest ability for fine tuning. If you look at the rpm tables they take pretty big jumps. Example of the tables it goes from 6000 - 6200 - 6400 - 6800. Not even close to ideal for high hp cars.
Last edited by LSWHO; 04-18-2011 at 10:15 PM.
04-18-2011, 10:14 PM
#5
Yes, really. I'm not saying it can't be done, because it can. But turbo cars can benefit greatly from an aftermarket ECM.
Corrected. The 5-600whp guys seem to all shift around 6200 from what I've seen. Not to say they can't go much higher especially in the higher powered ones, just most lt1 turbo builds I see are similar to this.
Corrected. The 5-600whp guys seem to all shift around 6200 from what I've seen. Not to say they can't go much higher especially in the higher powered ones, just most lt1 turbo builds I see are similar to this.
Last edited by LSWHO; 04-18-2011 at 10:20 PM.
04-18-2011, 11:22 PM
#6
Expensive is a relative term.
The stock LT1 Computer wasn't designed for boost and neither was the LS1 computer. An aftermarket unit with boost control, onboard logging, closed loop wideband control, programmable knock control and fully programmable mapping would be the best way to go for a really nice and reliable big power FI setup.
The stock LT1 Computer wasn't designed for boost and neither was the LS1 computer. An aftermarket unit with boost control, onboard logging, closed loop wideband control, programmable knock control and fully programmable mapping would be the best way to go for a really nice and reliable big power FI setup.
04-19-2011, 10:09 AM
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moehorsepower is a lt1 tuning genius, so if you have any questions he is the man. he tuned mine. the rpm problem with the lt1 is 7k. i made 670 thru a th400 s60 and 28" slicks at 14 psi pump gas, no meth. and thats with stock ported heads, and a bone stock lt1 intake. you will have to problem making 700 with a stock comp and opti!
moehorsepower is about to tune mine with a 3 bar!
moehorsepower is about to tune mine with a 3 bar!
04-19-2011, 10:17 AM
#9
04-19-2011, 11:19 AM
#10
Like 4SFEDZ says, only if you plan on spinning the motor past the 7K mark will an after market ECM be worth the cost. Tony Shepard ran on a stock PCM for the longest time until his new combo made power past 7k, so we had to go to the FAST system. Usually with forced induction you shouldn't need to go past that, My motor made those numbers at 6000 rpm, spinning the motor at the lowest RPM possible will add longevity, RPM's is the killer.
04-19-2011, 12:00 PM
#11
How much do you want to spend?
Exactly.
Like 4SFEDZ says, only if you plan on spinning the motor past the 7K mark will an after market ECM be worth the cost. Tony Shepard ran on a stock PCM for the longest time until his new combo made power past 7k, so we had to go to the FAST system. Usually with forced induction you shouldn't need to go past that, My motor made those numbers at 6000 rpm, spinning the motor at the lowest RPM possible will add longevity, RPM's is the killer.
04-19-2011, 12:26 PM
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I am running a small turbo pte76gts so it should be all in by 6000rpm. I am going to run a 3 bar map, speed density, and try to push boost into the low 20s on E85. I say 700+ because I am hoping it will make at least that hopefully more on the e85. I really think I would be pushing the stock pcm to far and drivability would suffer. After all it is a street car. I have absolutely zero boosted tuning experience so I would most likely go to a speed shop and get it strapped on the dyno.
04-19-2011, 01:18 PM
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If 700 is all your after, I would not go with an aftermarket comp. Now if your doin a max effort, all out car, sure go aftermarket. Is an aftermarket comp better, yes. But stock computer is plenty capable!
04-19-2011, 02:03 PM
#18
I didn't say that. You can make more revving higher though, these are small blocks. Shift that torque band to the right and watch the horsepower soar. My opinion is that reliability isn't a valid concern for capping revs at 7k unless you are stuck using an optisuck because you still have a stock PCM or you are building to a 200,000 mile component life expectancy like an OEM.
OP, I think you would be happy with an LS1 computer if you are building a street toy. If you want a track weapon, aftermarket computers have a lot of advantages that will get the car down the track faster and more consistently. A stock LT1 computer and optispark are going to be a crutch either way. Not that people with crutches can't run, just they can usually run faster without them.
OP, I think you would be happy with an LS1 computer if you are building a street toy. If you want a track weapon, aftermarket computers have a lot of advantages that will get the car down the track faster and more consistently. A stock LT1 computer and optispark are going to be a crutch either way. Not that people with crutches can't run, just they can usually run faster without them.
04-19-2011, 03:17 PM
#19
I didn't say that. You can make more revving higher though, these are small blocks. Shift that torque band to the right and watch the horsepower soar. My opinion is that reliability isn't a valid concern for capping revs at 7k unless you are stuck using an optisuck because you still have a stock PCM or you are building to a 200,000 mile component life expectancy like an OEM.
OP, I think you would be happy with an LS1 computer if you are building a street toy. If you want a track weapon, aftermarket computers have a lot of advantages that will get the car down the track faster and more consistently. A stock LT1 computer and optispark are going to be a crutch either way. Not that people with crutches can't run, just they can usually run faster without them.
OP, I think you would be happy with an LS1 computer if you are building a street toy. If you want a track weapon, aftermarket computers have a lot of advantages that will get the car down the track faster and more consistently. A stock LT1 computer and optispark are going to be a crutch either way. Not that people with crutches can't run, just they can usually run faster without them.
04-19-2011, 03:43 PM
#20
So you are saying if two motors make 700 hp and one comes in at 6000 and the other at 7000, the later will be faster? Not so, the 6000 rpm motor is going to reach its peak torque and HP quicker, yes you can gear the 7000 motor as the 6000 rpm motor, but a statement like that is just not so. Yes the opti was a problem for me until I got the Dynaspark so far so good. I have yet to see some one convert to the 24x set up and with no other changes make more power (unless it was a motor that needed to spin to or past 7k) Like I said, OP, Its all in the tune, mine is a DD with air and had absolutely no drive ability problems, instant boost no lag.I can tell you 4FEDZ was the same way..