How to convert a 202 to Delco

[Holden202T]

im not sure how the overall power figure changes drivability and down low torque ?

[RedWagonVC]

What I'm saying is that the overall goal is not peak power, and low rpm torque is more important than chasing peak power.

For instance you might recommend a big turbo and maybe even less compression again for maximum peak output but this would destroy the low rpm torque as we'd have bugger all comp, back pressure in the exhaust and no spool thus no power until high rpm. That's my understanding anyway..

[antus]

Whats your budget? I would keep the compression up and run a small to medium sized ball bearing turbo.

[delcowizzid]

im running a 202 with flat tops and big turbo.spools near instant but we have a tow style cam all down low grunt falls over around 4500rpm .it blows head gaskets too easy from the massive amount of air/grunt at low rpm.off boost its far gruntier than a 202 n/a LOL

[RedWagonVC]

The budget is 'enough to do it sensibly' I guess!
I haven't done a turbo before so matching a model to my needs is not easy for me!

My thoughts also were for a ball bearing turbo, capable of a tad more boost than is safe for the build (so we're not running g it on the edge) but not too large that it'll ruin spool times. Also a fmic sized correctly and pipework short enough to keep response on throttle good as possible.

Delcowizzid, what turbo are you running?

Anyone else, which have you run and how did you find them driveability/performance/ease of setup wise?

[delcowizzid]

holden202 is the resident 202 turbo delco guru LOL.
i built this for a mate but its far from reliable yet LOL sorting teething issues and the 2nd blown gasket but it goes hard on low boost but flat tops and the tow cam shoving air in at low revs is just making stupidly high combustion pressures and the gaskets just wont hold it in.

[Holden202T]

Guru or just the one that's wasted the most on it hehehe

In all honesty I'd hate my setup on a daily driver, it boosts way too late but has the mid to top end I need for a race car!

That said I'm sure a simple street cam change and suitably sized exhaust housing would make a killer street combo!

I've been wanting to try a eBay gt 35 with .63 ?? Exhaust to see how much sooner that spools than my .82 exhaust ... Just need the spare cash to try one one day

[delcowizzid]

i have a 0.63 that would probably fit straight on yours worst case need 1mm taken off in a lathe and it will fit.im looking for a 1.06 housing

[RedWagonVC]

That setup ^ is what we're probably going to be doing. Un-modified VK EFI inlet with a made up ex manifold (maybe we'll try and make one from a set of VK EFI extractors and some hard work! What sort of static comp is that thing running? and what sort of head gasket? (hopefully i'll be ok with the copper gasket, ARP studs and slight de-comp)

Also watch out fellas i've been getting in with the 'turbo lingo'-

From tons of looking around, checking out calculators, looking at curves on others' dyno sheets etc i've leaning toward the following:

Target 300hp at flywheel, able to do 400hp later on if necessary without too many changes. Midrange power at as near 2500rpm as possible, peak power at 5200rpm.

GT3071R with .50 A/R housing, FMIC, somewhere in the vicinity of 12-15psi (probably need closer to 20 for the 400hp mark, but that's 'maybe a down the track' thing)

What do you guys think about that? Seem about right? Only thing confusing me a bit is making sure I chose the right ex housing mount that i can get a flange for i suppose. Makes finding what parts i need and getting some pricing together difficult

[Holden202T]

I've been running 9:1 comp with 15-20 psi and methanol on my 202 with minimal issues with acl race series head gasket, but that could change with petrol!

I think your horsepower figures are achievable