High comp DET

Enzio · Post by **Enzio** » Mon Nov 03, 2008 1:58 pm

After reading PFB's last update on what CA18DETs can do I would like to find out about something I've been thinking about ever since I used a DE motor for my rebuild and had a look at the DE high comp pistons:

Has anybody ever built a high compression turbo CA18 motor or know of something similar? Obviously things like tuning is uber important for a motor like this, but it could potentially be a powerful motor with quick reponse and no need for high boost....

Any of the experienced guys like RAW have any opinions on this?

I'm just curious to find out if this is feasible for a street car.

ChemCool · Post by **ChemCool** » Mon Nov 03, 2008 2:00 pm

pinkfluffy , I think
Chem

Pinkfluffybunnys · Post by **Pinkfluffybunnys** » Mon Nov 03, 2008 2:39 pm

I'm just curious to find out if this is feasible for a street car.

Very much so. We already have High Compression Turbo charged motors running around already like the G5 Gti unit.

I mean there are a lot of benefits to the tuning process.

Overall Efficiencies will be greatly improved
Fuel economy will be improved
Off boost performance will be improved
Spool-up will be improved
Boost transitions will be smoother

But the trouble with such a set-up will be to make it detonation resistant; The New G5 engine uses a unique way to inject fuel almost removing the possibility on detonation.

Also having a Low static CR allow the engine to tolerate a lot more discrepancies in the tuning and the environmental conditions, I would like to build a CA18DET with a 9:1 CR or a 9.5:1 CR this is still a turbo friendly compression ratio and should greatly improve the off boost performance of the car also select a very efficient turbocharger for the motor

Enzio · Post by **Enzio** » Mon Nov 03, 2008 2:49 pm

I'm aware of the performance benefits, that's why I wanted to know if somebody has actually tried it with a CA18.

Those std DE pistons realise a CR of 9.5 afaik - not crazy high. I asked the question because I can't find a lot of info on the net with regards to turbo'ed DE's - most people just swop the DE for a DET.

The question is whether the DE pistons are made to a similar spec than the DET ones - in which case I might consider doing something like this next year when I want to build a "prototype" engine if possible with all of the remaining DE parts that I have and nobody wants to buy.

Enzio · Post by **Enzio** » Mon Nov 03, 2008 2:51 pm

BTW PFB - I haven't studied the Nistune manuals in detail: would the Nistune be able to use additional knock sensors of some kind??

Then this idea could work.

Pinkfluffybunnys · Post by **Pinkfluffybunnys** » Mon Nov 03, 2008 2:58 pm

Hmmmm

I’m not sure if I would use the N/A pistons. I would like to have forged units made that would increase the CR also I would change the con-rods for peace of mind.

Also I would immediately change for larger injectors and polish the combustion chambers and check my seats on the valves to avoid any hot spots, I will also get a good compression ring set for the pistons and a metal HG with Studs.

But there is a number of N\a CA18DE in PTa that’s been turbod with old SX stuff there an old wedged shaped one with a gold strip that I have seen so it can work. I think he runs 0.4 bar boost with a go-tech