which turbo for my CA18det

[schnabulator]

hi folks,
i'm from germany, sorry for my bad english!

certainly i mod my ca18det with pauter rods, cp pistons (83,5mm), 444cc injectors, xs power intercooler and 3" exhaust.

now i have to decide which turbo i will take.

i'm not sure, i'm looking for about 400 engine hp.

i want to drift and dragrace about 12sec times with slicks.

my favorit now is the gt2871r .64 (743347- 1)

or is the

gt2876r .64 maybe better for me (705330 - 1)?

have anybody here some experience with this combination?

when they starting to spool?

does it make sense to change the camshafts?

what throttle body can you suggest?

hope you can understand my english and can help me.

regads florian

[Jez]

The 2871 will be better out of those two - the 2876 will surge a lot.

[SM]

I use the 2871R 0.64, 392.5bhp - see my project thread for more details

http://www.sxoc.com/vbb/showthread.php?t=240135

[schnabulator]

I use the 2871R 0.64, 392.5bhp - see my project thread for more details

how much pressure do you use?

when does it starts to spool?

[liquidsmoke]

Bear in mind most people don't get that much HP. SM has a very good VEMS ECU and has been ignition mapped properly by APT who are very good. He only runs 1.4bar iirc.

I ran 1.4bar on my 2871R and only made 350bhp, and the fuelling was 0.82 lambda on max boost, lowering to 0.80lambda at about 6k revs. Ignition advance was boost limited; I had to retard it from optimum power to prevent det at high RPM. I also have some headwork and a 7.93:1 CR. And CA16 inlet cam.

Full boost usually around 3.8k.
EDIT: dyno says 3.7k.

[TomK]

Full boost (1.4bar) at 3.8k with 350bhp thats nice , damn, regret buying the turbo i did now

[Big G]

Liquid smoke get yourself a wideband mate, O2 sensors are really worth anything apart from as a warning system

[alanjuggler]

tbh, i've not noticed compressor surge to be a problem with a 2876.

which i would have thought would be made worse with standard cams (i.e. like me) - if the air can't flow into the engine, it's going to sit in the intake. or is it the opposite - because the cams are restricting the turbo spooling, is it keeping it under control?

full boost at around 4100-4200 rpm currently running 1.45bar - no power figure as of yet.

[liquidsmoke]

I have a wideband of course. lol. I'm not going to map my car with a narrow band am i?

[Big G]

and the fuelling was 0.82 lambda on max boost, lowering to 0.80lambda at about 6k revs.

Narrow band reading not wideband

[liquidsmoke]

What are you talking about?

Lambda = AFR/AFR(stoich)

The number means the same regardless of sensor.

[Big G]

Nope, the number doesn't mean the same regardless of the sensor

And lambda doesn't mean stoich

0.82v which you wrote as your value at mx boost wouldn't even read on a wideband, on a narrow band it would read as rich

But for you information the comparrison (guesstimate) for your narrowband reading would be about 1.95v on a wideband giving you a stoick of about 11.9:1 at max boost


Accuarcey on a wideband is far beyond that of a narrow

[Stevecarter200]

Read again G, you are indeed. He doesnt mention 0.82V at all, he wrote 0.82 lambda, which is the same as an AFR of 12:1.

Just like 1.00 lambda is the same as 14.7:1 AFR.

[liquidsmoke]

Yeah I'm not talking voltage, I'm talking Lambda. Which is why I wrote lambda after it and not a 'v' I just couldn't be arsed to convert it to AFR, because I was looking at the pretty graph my VEMS drew.