MAKING 4EFE STARLET FASTER

[Sparco79cz]

Hey guys,
I bought a EP91 4EFE Starlet a year ago for hillclimb racing. I’ve already upgraded the brakes and suspension, now I want to make it faster. I can’t swap the engine or use a turbo because of class rules. I’m aiming for around 20–30 HP more.

Intake:
I read that a Corolla E11 intake manifold could help. Is the E11 throttle body enough, or should I use one from a 7AFE? I know that I need cold air.
Exhaust:
I know I need a better exhaust manifold. Can I use one from a 4AFE, 7AFE, or 5EFE, or is it better to get an aftermarket one from eBay?
Other:
Can you recommend better fuel injectors, or can I stick with the original ones?
Will advancing or retarding the cam timing (for example by one tooth) improve engine performance?
Any other ideas?
Engine:
I’ll probably do a rebuild next year. What should I redo or upgrade while I’m at it? Camshaft? Pistons? Is it possible to get some upgraded parts online and for normal price?
Gearbox:
I want to ask about Final Drive for my gearbox. I probably have C52. C56 should be plug and play but I cant find any. Is there any better FD option to buy online for my gearbox?

I am from Europe - Czech Republic and there are not many starlets. From time to time I can find some old toyotas for parts but there are not many. I´d be glad for any advice.

IG: @speedstar_starlet

[swampy442]

Getting power out of NA engines is very expensive, and the gains are small vs what you spend. In all honesty I’d save your money for the next project
Try Japan maybe for funky manifolds, and intakes, advancing the timing and adding more fuel, better breathing, more revs. It it’s marginal gains

[TO73074E]

I used to have a Toyota Starlet Glanza with the 4EFTE engine and obviously the turbo makes a fair difference. The manifold on the 4EFTE has a restriction on the 3rd runner where the stud is so people often changed these. I don't know if this is the same with the 4EFE manifold?

I used to use www.toyotagtturbo.com as my bible and it was a really helpful site. Check this link out: https://www.toyotagtturbo.com/community/index.php?...

And this is a talk about the manifolds for the 4EFE: https://www.youtube.com/watch?v=K1P0p1oVzcs

He seems to think you can't gain much on the 4EFE, apparently a custom exhaust, Corolla inlet manifold and piggyback ecu will get 5-10hp if you are lucky.

Nevertheless, all the best with it!