2.5L Power Upgrade

Tech Question


Dave Karp, Haskell, NJ, 1991 Dodge Spirit 2.5

Fixing up a a ’91 Dodge Spirit that was left to my son whenmy Mom died. Its 2.5 EFI auto, I am putting on a set of Shelby “clamshell”wheels getting some 205 60 15 tires on it, new struts, got a nice takeoutradio at Carlisle. Not looking to take down Jimmy Addison’s Silver bullet,but would like to get a little more out of the 2.5. it is pretty anemic.

I do think the “cat” is clogged so I will start there. I also noticed this carhas burned oil since new. A quart to 800 miles (dealer at the time called itnormal) we got nowhere with Chrysler, I have had others with the same issueas well. I was told that they were made with the rings were lined up duringassembly. There was always oil in the breather leading me to think “blowby”. Mopar even had out a replacement aluminum valve cover to help this andI did that as well.

Anyway my question comes down to this: I would like tohave the car at least where it is not an out right dog, and maybe correctthe oil burning issue If I had to put a number on it, Id like to see it ableto run mid 16s and I would be tickled. Cheap and simple would be best it’s ateens 1st car. My list of to do on the engine is
1)Head gasket… Leaksoil
2 )Timing belt… 20 years on 1 belt is long enough.
b)Water pump
c)A/C belt and sepentine
3)try whatever the ever wise Mopar Guru suggests



The engine is quite undervalved and almost beyond help without positivemanifold pressure. The TBI is just horrendous for HP. I think I’d punch outthe cat, change any ribbed air inlet hoses to straight, and just drive it.

Try a restrictor in the PCV line for the oil consumption problem.

There was a Mexican SMPI 2.5L version which was a lot better (tuned intake,etc.), also the US FFV version was similar to the south-of-the-border model.

Having a super-dog for a teen’s first ride really isn’t a bad thing.


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