1985 Engine Mods Recommendations
Thread Starter
8th Gear
Joined: Nov 2020
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From: Dade City Florida
1985 Engine Mods Recommendations
Hello all,
My TPI has 110k miles and no modifications outside of a Cat delete and a muffler delete. Tranny was rebuilt a few years ago. I want this engine to achieve the ideal 1 hp per cubic inch, but if the block can handle more, that would be better. How much parts cost isn't a problem for me. Any ideas/recommendations would be appreciated.
My TPI has 110k miles and no modifications outside of a Cat delete and a muffler delete. Tranny was rebuilt a few years ago. I want this engine to achieve the ideal 1 hp per cubic inch, but if the block can handle more, that would be better. How much parts cost isn't a problem for me. Any ideas/recommendations would be appreciated.
Team Owner
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From: Athens AL
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Easiest way to just achieve the goal of 350bhp is headers, then switch to Miniram, which will get you to the 300hp range, then have heads/cam.
A later L98 might be able to do it with just cam, but 85 has the '624 heads which are not all that good, and won't quite flow enough to get there. So you must decide whether you intend to go beyond your goal or just want enough head to flow it. If you intend to stay as a 350ci, I'd go with AFR 190s. Add in a reasonable cam, maybe 218/228@050 and you probably get there. Remember 85 is flat tappet, not a roller cam (though you can convert). Add 1.6RR and a custom tune on a dyno and you should be there or above.
A later L98 might be able to do it with just cam, but 85 has the '624 heads which are not all that good, and won't quite flow enough to get there. So you must decide whether you intend to go beyond your goal or just want enough head to flow it. If you intend to stay as a 350ci, I'd go with AFR 190s. Add in a reasonable cam, maybe 218/228@050 and you probably get there. Remember 85 is flat tappet, not a roller cam (though you can convert). Add 1.6RR and a custom tune on a dyno and you should be there or above.
Team Owner
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From: Hartford WI
In that case, rebuilt trans, D44 rear end, better intakes and headers and a 383 with a custom tune should net you well out of your power requests.
Race Director
Joined: Jun 2004
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From: WI
Are you doing the work and tune yourself? There are some inexpensive ways like later year heads etc but to many mods will need a tune or aftermarket efi controller. For that goal I think you could just do heads and intake. Have your eye on any?
Team Owner
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From: Hartford WI
I'd pass on tuning since it is a lot of work and a "One Off" but I'd definitely think headers. They made quite a bit of difference when I started to modify my L98. Intakes made some difference but the headers added more. Way better after the tune if you want to believe the wife's subjective opinion.
Intermediate
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I have a Holley sniper on my 85 along with cam , edelbrock carb intake , exhaust , ect..... . You can play with tuning as little or as much as you feel like . I don’t know the HP but it’s definitely a lot quicker .
Last edited by TrailerPark Hero; Feb 3, 2021 at 09:34 PM.
Team Owner
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From: Hartford WI
Why would you have to play with the tuning? If it is self tuning, it should tune itself after you set the basic parameters. If it is not self tuning and it is set right and you don't make changes, it should not need to be worked on. Not sure I see.
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Last edited by TrailerPark Hero; Feb 3, 2021 at 10:30 PM.
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Team Owner
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From: Hartford WI
OK. I was trying to see if self tuning is going to be as good as a professional tuner with a dyno
Pro
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Because the system is not "self tuning". It only tunes the fuel poundage to meet the air fuel ratio in that cell of the fuel map. The same pretty much for the ignition timing: it only sets the timing to what it is demanded at that spot in the timing map. You have to tell it what those values are. The system does have some generic fuel and timing files that should get you started but the tune would likely need to be tweaked some to maximize the power and make the engine run as well as possible.
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Because the system is not "self tuning". It only tunes the fuel poundage to meet the air fuel ratio in that cell of the fuel map. The same pretty much for the ignition timing: it only sets the timing to what it is demanded at that spot in the timing map. You have to tell it what those values are. The system does have some generic fuel and timing files that should get you started but the tune would likely need to be tweaked some to maximize the power and make the engine runs as well as possible.
Pro
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From: Wisconsin
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It’s pretty cool that it can control timing if you want it to but not necessary. But it’s also capable of controlling Nitrous and can handle boost up to 20psi . Gives me options for when I swap to a 6.0 ls . I’m not saying it’s the best setup and everyone should run it . All I’m saying is it’s an option for someone wanting to get more power from a stock l98
Team Owner
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From: Hartford WI
Not sure why since 90 was Speed Density and is less adaptable than MAF when you do small mods. What would you say is the advantage?
Last edited by aklim; Feb 4, 2021 at 09:47 PM.
Team Owner
Joined: Jul 2004
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From: Hartford WI
Because the system is not "self tuning". It only tunes the fuel poundage to meet the air fuel ratio in that cell of the fuel map. The same pretty much for the ignition timing: it only sets the timing to what it is demanded at that spot in the timing map. You have to tell it what those values are. The system does have some generic fuel and timing files that should get you started but the tune would likely need to be tweaked some to maximize the power and make the engine run as well as possible.