1990 SC questions

Dev893

Registered User
Couple questions. Main one is how much power can the stock auto trans handle? The member only forums aren't working for me for some reason
 
Not sure the answer but when you pay the yearly dues to become an SCCoA Member you get full access the forums. Your tag says "Registered User" Another awesome perk is you don't have to answer the "random" question to post in the forums. :D
 
Not sure the answer but when you pay the yearly dues to become an SCCoA Member you get full access the forums. Your tag says "Registered User" Another awesome perk is you don't have to answer the "random" question to post in the forums. :D
OK thanks lol. Have you built quite a few of these?
 
OK let me ask a more interesting question.
How much power do you guys think I'll get from
The following mods

76mm MAF
75mm throttle body
42# injectors
255lph fuel pump
Mag Power 10rib 15% pulley kit
STP 3" CAI kit
Flowmaster 2 1/2" cat back
Stage 2 cam 265int 281exh
And of course a tune
 
Not enough to hurt a good working trans. With that much overdrive, stock intercooler and an early model blower you will just make a lot of heat past the eight mile.
 
OK let me ask a more interesting question.
How much power do you guys think I'll get from
The following mods

76mm MAF
75mm throttle body
42# injectors
255lph fuel pump
Mag Power 10rib 15% pulley kit
STP 3" CAI kit
Flowmaster 2 1/2" cat back
Stage 2 cam 265int 281exh
And of course a tune

I would say your mods will give ya somewhere in the 230s at the wheels. Biggest concerns I see are lack of cooling the intake temps and factory m90.

-Tim
 
I would say your mods will give ya somewhere in the 230s at the wheels. Biggest concerns I see are lack of cooling the intake temps and factory m90.

-Tim
What if I were to upgrade the intercooler and go to a late model blower or have the stock one ported I would also put a 160° or 180° thermostat in
 
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would I see bigger power gains if I just went with a 5% overdrive pulley kit and a full exhaust with intake and cam? Would I still need injectors and fuel pump I I whent that route?
 
Early model SCs max out the injectors in stock form. Literally anything you do to them, you should upgrade the injectors. When upgrading the injectors, it is also necessary to get a tune, which that alone will help with your power output. Given how cheap you can pick up a late model blower, the early ones aren't worth messing with. Exhaust will give you minimal gains at a relatively stock power level, and unfortunately short of spending lots of money on Borla mufflers, SCs don't sound good with loud exhaust, so I would spend that money elsewhere, namely on a better intercooler. If you have time and fab skills, a front-mount setup would perform the best, but a Ken Wagner double intercooler will be a big help, and will bolt right in place of the stock unit. Also there are decent gains to be had with a cam swap, but you will also need to upgrade the valve springs.
 
Early model SCs max out the injectors in stock form. Literally anything you do to them, you should upgrade the injectors. When upgrading the injectors, it is also necessary to get a tune, which that alone will help with your power output. Given how cheap you can pick up a late model blower, the early ones aren't worth messing with. Exhaust will give you minimal gains at a relatively stock power level, and unfortunately short of spending lots of money on Borla mufflers, SCs don't sound good with loud exhaust, so I would spend that money elsewhere, namely on a better intercooler. If you have time and fab skills, a front-mount setup would perform the best, but a Ken Wagner double intercooler will be a big help, and will bolt right in place of the stock unit. Also there are decent gains to be had with a cam swap, but you will also need to upgrade the valve springs.
So I I whent with a late model blower and my first part list with a custom front mount intercooler what do you estimate my power to the wheels to be? I'm not looking for lots of power just enough to shut all the hondas and some of the SN95 mustangs in my area up. I am in CA so cats would not than likely stay on the car paired with a resonater exhaust shouldn't be too loud I guess realistically my power goals are about 250rwhp and 350ft-lbs to the wheels at least and I will probably do a gear ratio swap and put in 3.73's like the FAQ suggests
 
When my son had his 1990 automatic it would turn in low-mid 14 at around ninety mph. It had new head gaskets mild ported heads ported and polished exhaust manifolds stock exhaust with gutted cats and resonator with a 5% pully and a late model maf. The car weighed 4080 lbs with driver. It penciled out to like 250 rwhp. It was at the wall. It was out of cool air and fuel. Fastest car at his schooI and the only car that would smoke the tires for 300 feet across the parking lot. Boy was the principal pissed!
 
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So I I whent with a late model blower and my first part list with a custom front mount intercooler what do you estimate my power to the wheels to be? I'm not looking for lots of power just enough to shut all the hondas and some of the SN95 mustangs in my area up. I am in CA so cats would not than likely stay on the car paired with a resonater exhaust shouldn't be too loud I guess realistically my power goals are about 250rwhp and 350ft-lbs to the wheels at least and I will probably do a gear ratio swap and put in 3.73's like the FAQ suggests

My advice would be
-late model blower
-MP inlet
-42# or larger injectors
-80mm GT MAF
-75mm TB
-FMIC
-10-15% OD
-Tune

That should get you over 250rwhp, and be a fun car!
 
Your in California, right? If that's so then the first thing you have to do is pass the visual. Unless you have carb numbers for your un stock parts you fail. Correct?
 
Your in California, right? If that's so then the first thing you have to do is pass the visual. Unless you have carb numbers for your un stock parts you fail. Correct?

Only on intake. But I know where I can get carb stickers iif needed but I plan on keeping stock intake for this purpose. Also since it came factory with a supercharger I don't think I have to do visual just emmisions so I can't do injectors till after smog test which is OK cause it'll take a little bit to save up money for the parts
 
My advice would be
-late model blower
-MP inlet
-42# or larger injectors
-80mm GT MAF
-75mm TB
-FMIC
-10-15% OD
-Tune

That should get you over 250rwhp, and be a fun car!

Will the stock AOD trans handle that? Also won't the late model blower alone add power?
 
The late model blower need the injectors and tune all at the same time. I would add late model maf and tb at the same time. Also a late model fuel pump is rated higher.If it's running correctly it should pass emmissions. These parts all work together.
 
Yes the late model alone will add power, but the MP inlet is a huge improvement, and is well worth the money. By doing that, you can get to your power goal without having to go into the engine at all, and it will look pretty stock, so even though the inlet doesn't have a CARB number, they likely will not notice it, especially if you grind off the "Magnum Powers" logo. Also, I seriously doubt they will fail you for larger injectors. The only visual difference between them is the color of the top, and if you are really worried about that, paint the tops red. As for the stock trans handling it, it is going to come down to how good condition the trans is, plus how lucky you are. I call the AOD a DOA trans. I have never managed to keep one alive for any length of time, even at stock power levels, so I won't waste my time with them anymore, but other people have had good luck with them, so who knows.
 
Yes the late model alone will add power, but the MP inlet is a huge improvement, and is well worth the money. By doing that, you can get to your power goal without having to go into the engine at all, and it will look pretty stock, so even though the inlet doesn't have a CARB number, they likely will not notice it, especially if you grind off the "Magnum Powers" logo. Also, I seriously doubt they will fail you for larger injectors. The only visual difference between them is the color of the top, and if you are really worried about that, paint the tops red. As for the stock trans handling it, it is going to come down to how good condition the trans is, plus how lucky you are. I call the AOD a DOA trans. I have never managed to keep one alive for any length of time, even at stock power levels, so I won't waste my time with them anymore, but other people have had good luck with them, so who knows.
is the C4 a direct trans swap? Will it still be good for highway use if I did swap in a C4 with 3.73 gears? Also not worried about visual larger injectors can change emissions which will cause me not to pass
 
If tuned properly, large injectors will have no effect on actual tailpipe emissions. As for the C4 questions, no it is not a direct swap, and no 3.73s with no overdrive is not at all highway friendly. A C4 swap is for track-only cars. I would leave the DOA alone until it actually dies, then either do a 5-speed swap, or if you want to keep it an automatic, swap it for a 4R70.
 
AOD will need an A servo (weren't used in SC's til 91, you most likely have a C)or an A+ super servo, so that you dont burn out overdrive. 300m input shaft (not a hardened one, they tend to be brittle), factory is known to break between 280-350hp. and a TCI shift kit to clean up the shifts
 
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