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Tuning for TPI

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Old 08-20-2018, 05:37 PM
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Steves LS6
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Default Tuning for TPI

Hello, I have a Speed Density car I put a new motor in. It has an aggressive cam in it and I am having some issues with the idle. The person that did the engine swap has given up on trying to get the tune right is there somewhere in the Chicago area that can tune an OBD I SD car?
Old 08-20-2018, 07:12 PM
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Irocz187
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What equipment were you using before and were you altering the prom or swapping chips?

It is a huge undertaking for a beginner to learn about tuning and to do it yourself but it is possible. And if you still run a 350 then it really isn't that bad. Some say if your cam is too big then the tpi can't handle it but don't have the discussions and the evidence to link at the moment. I used equipment from moates.net and their guides and resources.
Old 08-20-2018, 07:13 PM
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WhiteC1
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Originally Posted by Steves LS6
Hello, I have a Speed Density car I put a new motor in. It has an aggressive cam in it and I am having some issues with the idle. The person that did the engine swap has given up on trying to get the tune right is there somewhere in the Chicago area that can tune an OBD I SD car?
Try Scott Hansen (http://www.scotthansen.net/). He was able to tune my 78 CJ7 with an 88 IROC-Z TPI. I had idle problems because my Jeep is a manual, and the computer was set up for an automatic. He’s really sharp and if he can’t do it, I’m sure he can point you to someone who can. Good Luck!

John
Old 08-20-2018, 07:18 PM
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bjankuski
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Try wb dyno in west bend wi.
Old 08-20-2018, 07:21 PM
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Originally Posted by bjankuski
Try wb dyno in west bend wi.
Are you working there? Soon as I get my AC fixed, I think I might need someone to readjust the NON-WOT section of my tune. Something just not to my liking.
Old 08-21-2018, 08:35 AM
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KyleF
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Originally Posted by Irocz187
What equipment were you using before and were you altering the prom or swapping chips?

It is a huge undertaking for a beginner to learn about tuning and to do it yourself but it is possible. And if you still run a 350 then it really isn't that bad. Some say if your cam is too big then the tpi can't handle it but don't have the discussions and the evidence to link at the moment. I used equipment from moates.net and their guides and resources.
This is because TPI is a batch fire system. Very sensitive to low speed idle having low vacuum with a large cam. usually remedied by setting the Idle RPM higher. Of course this is a very simple explanation to a lot of things going on, but it is the short and sweet.
Old 08-21-2018, 11:49 AM
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Steves LS6
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Originally Posted by Irocz187
What equipment were you using before and were you altering the prom or swapping chips?

It is a huge undertaking for a beginner to learn about tuning and to do it yourself but it is possible. And if you still run a 350 then it really isn't that bad. Some say if your cam is too big then the tpi can't handle it but don't have the discussions and the evidence to link at the moment. I used equipment from moates.net and their guides and resources.
I do not know what equipment he used to tune the car with. I believe he put some type of adapter in the computer to use a chip that you could reprogram. The crate engine I have is an ATK HP89.
https://www.high-performance-engines...ine-p/hp89.htm
I have 30lb injectors, ported plenum, TPIs big mouth intake, ASM runners, headers it's also a manual transmission. In order to keep it running smooth he set the idle to 925 rpm. It drives great other than the idle issue.

Last edited by Steves LS6; 08-21-2018 at 11:52 AM.
Old 08-21-2018, 11:49 AM
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Originally Posted by WhiteC1


Try Scott Hansen (http://www.scotthansen.net/). He was able to tune my 78 CJ7 with an 88 IROC-Z TPI. I had idle problems because my Jeep is a manual, and the computer was set up for an automatic. He’s really sharp and if he can’t do it, I’m sure he can point you to someone who can. Good Luck!

John
I was looking at his web site.
Old 08-21-2018, 11:50 AM
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Steves LS6
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Originally Posted by bjankuski
Try wb dyno in west bend wi.

I will call this place as soon as I have some time. Thank you.
Old 08-21-2018, 01:53 PM
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Originally Posted by Steves LS6
I will call this place as soon as I have some time. Thank you.
I'd prefer to use a dyno tune as opposed to the "guess a tune" chips.
Old 08-21-2018, 01:59 PM
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Originally Posted by aklim
I'd prefer to use a dyno tune as opposed to the "guess a tune" chips.
I agree.
Old 08-21-2018, 09:55 PM
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SpedRacr93
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Originally Posted by Steves LS6
In order to keep it running smooth he set the idle to 925 rpm. It drives great other than the idle issue.
You said "aggressive cam," so, how low do you think it should idle?

Old 08-22-2018, 06:23 AM
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Originally Posted by SpedRacr93
You said "aggressive cam," so, how low do you think it should idle?

When he gave me the car back the idle was at 850 rpm. At that rpm it was running rough, and surging. When the fan would turn on it would die. Now the idle is set at 925 rpm and when the fam turns on it will run rough till the fan turns off. It also runs rough when I turn the A/C on.
Old 08-22-2018, 07:56 AM
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Originally Posted by Steves LS6



When he gave me the car back the idle was at 850 rpm. At that rpm it was running rough, and surging. When the fan would turn on it would die. Now the idle is set at 925 rpm and when the fam turns on it will run rough till the fan turns off. It also runs rough when I turn the A/C on.
It is a 350 making 375HP. The injectors might be a little large for that application?
Old 08-22-2018, 08:18 AM
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Originally Posted by aklim
It is a 350 making 375HP. The injectors might be a little large for that application?
Agree, as I said above... the extra RPM will help with air velocity. The other part of it is running a elevated fuel pressure to help atomize the fuel. If your injector is too large, you might not be able to get a good mixture with atomized fuel.

Are you doing any scanning, what is your 02, Cross counts, and BLMs telling you?

If you have proper data logging and long term data from driving, it is not a "guess" tune". The "guess" may be where the starting point is, but even your Dyno tuning guy will have to start somewhere too and he will log data during the run. Make adjustments and do another pull. If your mail order guy is willing to read your data logs and make adjustments, it is essentially the same deal without the nice graph of before and after.
Old 08-22-2018, 08:31 AM
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Originally Posted by KyleF
Agree, as I said above... the extra RPM will help with air velocity. The other part of it is running a elevated fuel pressure to help atomize the fuel. If your injector is too large, you might not be able to get a good mixture with atomized fuel.

If you have proper data logging and long term data from driving, it is not a "guess" tune". The "guess" may be where the starting point is, but even your Dyno tuning guy will have to start somewhere too and he will log data during the run. Make adjustments and do another pull. If your mail order guy is willing to read your data logs and make adjustments, it is essentially the same deal without the nice graph of before and after.
I'm not sure if the guy really made the appropriate adjustments for the larger injector. Hopefully he didn't jack up the pressure or it would add another variable.

Agreed. The "guess a tune" I am referring to are those that write a tune based on what you said you have and go with that. Without data logs, it is guessing, IMO. Sure, he can be responsible and backpedal it a little so as to have safety or go as far as he dares and increase the risk of something going wrong. Actually, I do like to see the before, after and DURING. That tells me you are pushing it to max power and back off once it goes over the top and correlate that with the ECM readings for best results.
Old 08-22-2018, 08:57 AM
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He does have data logs and I’ll see if I get him to post some. He has built and tuned many TPI’s according to him the SD cars are much more difficult to tune than the MAF cars. I am guessing it could be that the IAC is bad. It is the original one to the car.

There are people with similar motors and they are running 50lb injectors. From what my reasearch has showed me these people get their cars to run correctly.

This is a learning process for me and I appreciate all the responses.

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Old 08-22-2018, 10:18 AM
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Originally Posted by Steves LS6
He does have data logs and I’ll see if I get him to post some. He has built and tuned many TPI’s according to him the SD cars are much more difficult to tune than the MAF cars. I am guessing it could be that the IAC is bad. It is the original one to the car.

There are people with similar motors and they are running 50lb injectors. From what my reasearch has showed me these people get their cars to run correctly.

This is a learning process for me and I appreciate all the responses.
If he were a good tuner he would NOT need to rely on the MAF to cover for his lack of ability Before I toss money on the IAC I'd get the tuner to do the chip on the dyno.

Yes you CAN use 50 pph injectors. I have 42 pph injectors feeding a motor making 420 RWHP That said, larger injectors means that there is more fuel per millisecond. Could make it harder tune for idle if it is too large. Beyond a certain point, it might not be good regardless of the tuner having skills or not.

I suggest you get a tuner to adjust it all over instead of simply jacking your idle up. It might be just masking a problem with the tune.
Old 08-22-2018, 12:38 PM
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Originally Posted by aklim
If he were a good tuner he would NOT need to rely on the MAF to cover for his lack of ability Before I toss money on the IAC I'd get the tuner to do the chip on the dyno.

Yes you CAN use 50 pph injectors. I have 42 pph injectors feeding a motor making 420 RWHP That said, larger injectors means that there is more fuel per millisecond. Could make it harder tune for idle if it is too large. Beyond a certain point, it might not be good regardless of the tuner having skills or not.

I suggest you get a tuner to adjust it all over instead of simply jacking your idle up. It might be just masking a problem with the tune.

He told me that the reason he raised the idle was to "band aid' the issue. I was hoping there was a place near me to go and have it properly tuned but so far the only place that someone suggested is WBD. It's about an hour and a half away so I need to make some time to get up there.

What would be the correct size injectors? 22lb or 24lb?

Last edited by Steves LS6; 08-22-2018 at 12:52 PM.
Old 08-22-2018, 01:06 PM
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Originally Posted by Steves LS6
He told me that the reason he raised the idle was to "band aid' the issue. I was hoping there was a place near me to go and have it properly tuned but so far the only place that someone suggested is WBD. It's about an hour and a half away so I need to make some time to get up there.

What would be the correct size injectors? 22lb or 24lb?
Soon as you say "band aid", it doesn't speak well of you in my book. With what you have said, I'm thinking he is relying on the MAF to compensate for his lack of skills. I'd definitely give WBD a look if you want something close to you. Call them first and see if they will work on it. Not even sure if LPE works on them anymore. The guy who tuned my setup is now in North Carolina with Joe Hornick Racing.

Right now you have 30 so if they are newer, I'd try to see if the tuner can make it work before buying 24. Go with what the tuner thinks he can do with what you have.


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