Who knows there turbos?

[james13009]

Question:
When running on stock internals and Wanting more than 300bhp, is it plausible (and safe) to switch out the ct20b for a larger and cooler running turbo to take you further up the hp gains say 320/330bhp?? and prevent engine knock (a distruction) - because the intake air is alot cooler

(Assuming your running a 'power FC' also asumming you would need larger injectors or is stock fine??)


Or am I taking utter cr@p? ....

[Ryan S]

i could be wrong, but i'm sure the conrods can't take as much as that, somebody will be along to verify shortly

[Steve-O 2007]

im sure ive saw people running 320 on stock internals with a Rev3 bolt on mods and remap.. unless you mean 320 Whp

[tubby_tony]

320 fwhp is achievable on a rev3+ with ct20b, standard engine internals, good bolt on goodies including standalone engine management and good remap. Standard injectors are at their limit though.

There are members on here hitting that figure with above mods. If I mapped in my WI kit running 50/50 water/meth I would be hitting that figure.
Could exceed it if I ran more methanol. The block can take it as long as you have a good map producing minimum knock and detonation.

IIRC Fensport were running a 400bhp Corolla fitted with standard internals 3sgte block back in 2004. Not sure how long it lasted though.

[james13009]

Yep found a 9 page thread on it now. It is possible you just need to avoid engine knock and "detonation" by running lower charge temps, a
A lot of people use water injection to avoid this.

If looking in to putting in a new turbo kit with this in mind .. which on would you choose?

[Ryan S]

for that amount of power, there's no point/need in changing the turbo.

[james13009]

Why??

it get very expensive as soon as you go over 300. But look at it as a staged process and this is the first step.

Sounds logical to me for... Bhp v £

[Ryan S]

because, as stated above, 320/330 is acheiveable with the standard turbo so why change it?

[james13009]

How inefficient is the CT20B when boosted up? It seems most of the engines that I have heard blow up, are from guys running the CT20B at high boost. Do they tend to become very inefficient and end up pumping just hot air, increasing the risk of detonation? That's one reason why I am leaning towards a larger turbo, as I know the CT20's are rather small, and I want to keep the intake charge cool.

[Ryan S]

no idea man, i know the ct26 runs out of puff at around 5k rpm,

[james13009]

If I can get more hp out of it brilliant, just not seen anyone over 310bhp on stock turbo (maybe I'm not looking hard enough) . Although It's true I read somewhere they are rated to well over 300bhp

Not trying to skimp on a rebuild might happen one day, just more fun to do in smaller stages

[Peter Gidden]

The CT20B is perfectly good within it's design window, which is known to be around 17psi. Which is where fuel cut occurs anyway.

The torque developed by the engine is going to be based on the compressed volume of air and fuel mixture entering the engine. Force more in, and you have the potential for more torque.

Switch to a bigger turbo and you will produce lag. Plus you won't be working within the turbo's optimum flow characteristics.

Which is why turbos are "sized" to an engine size - i.e. air flow.