.96 a/r turbine

[red240ne]

How efficient would it be to run a .96 a/r turbine on a KA at only 10 psi? Would it be pretty pointless around lower boost levels?

[TrunkMonkey]

you can forget about it spooling any time soon.

whether or not it's worth depends on the power your looking for. what turbo are you looking at? an a/r that big is usually on a turbo for diesels.

-demetrius

[Nathan]

For a T3 turbine? That's huge...

[IvoryJ30t]

right. youll hit full boost at redline.

not really, but you get the point...

[j-z]

jesus christ man are you crazy? with the KAs low rev limit youll want something way smaller than that. im gonna go with a .48 ar but if you want a little more topend i would go no bigger than a .63 ar.

[red240ne]

.96 A/R on center turbine housing.60 A/R compressor housingInducer diameter 2.03"Exducer diameter 2.75"P-trim exhaust wheel for quick spool upThe turbos T5/T6 trim will flow approx 45lbs/min. approx 450 HPthe compressor is between a Turbonetics S-trim and V-trim wheelTurbo come with a gasket set and is backed by a 1 year warranty through Garrett!

quote from ebay. It's a TO4B. so no, not a T3 turbine.

[j-z]

what are you going to use your car for?

[MarkEmark]

It'd be a good turbo if KA's revved up to 9000 rpm

That's freakin' huge. Double what my turbine ratio is (.48), and I LOVE how mine spools and boosts quickly

[90lkn4swp]

It'd be a good turbo if KA's revved up to 9000 rpm

What you think the red line could be with this?

-Stainless Steel Black Nitrided INTAKE and Stainless Steel Black Nitrided EXHAUST valves-Ka24de High-Performance DUAL Valve Springs and Titanium retainers-Port & polish head

is there some kind of roller rockers for the ka or would the O.E. ones do? Bottom End-Shorter Forged Con/Rods-Ballanced Crank-Ross 8.5:1CR Forged Pistons

also does anyone think this might be over kill for a Garrett T3/60-1 W/.48 A/R Turbine?

COMPRESSOR SPECS:T04S .70 A/R housing 60-1 TRIM wheelTURBINE SPECS:T3 .48 A/R housingHIGH FLOW 76 TRIM stg 3 wheel oil lubricated centersection.

COMES STANDARD WITH 360 DEGREE THRUST BEARING!!(i dont know what a THRUST bearing is )

[trpower7]

SEARCH. I'm going to tell you to do it no matter what anyone says. We cannot outline the million factors and problems you've already listed. You need to do more research on the KA. The fact that you put "roller rockers" in a post about something to a KA is fact enough. SEARCH and read for a few months.

[MarkEmark]

I have no idea what redline the things listed would yield, but I doubt it'd be near 9000 rpm.

You're gonna need more than valve springs/valves/port n polish to get any power out of the KA at 9000 RPM--the insane overlap needed for cams making power at around 9000 rpm would KILL the turbo. Turbo's dont like overlap. I can't see the KA to ever being brought up to 9000 rpm unless it were fully built for racing and actually made POWER up there...It'd take a LOT of work, money, and tuning to get a KA to not only be EFFICIENTLY turbocharged, but capable of revving up to 9000 rpm.

How can valves be both nitride coated and stainless steel? If you're talking about the ones available on ka24de.com, they come in either stainless steel OR nitride coated.

Anyway, the redline I listed was only theoretical--I was using it as a point to say that a .96 A/R turbine would be SO slow in spooling and that it'd hit boost so much later that you'd want a higher redline unless you want a powerband in between 5 and 6.5k

I HATE people who say the KA's have rockers or "roller" rockers--it shows me that they've never had their valve cover off.

[90lkn4swp]

not to start an argument but i think the ka does have rockers i know for a fact it doesnt have a head set up like the ca

i was just wondering if somone made rollers for the ka if it wouldnt work better then i guess thats the answer i was looking for

i have searched on and off for about a year and a half nowsometimes the search doesnt bring me ****

and i have had my valve cover off ive only worked on domestics and this would be my first import but if those arent rockers then what are they?

[TrunkMonkey]

not to start an argument but i think the ka does have rockers.

no one said it didn't. it doesn't have ROLLER rockers.

-demetrius

[MarkEmark]

I see that you have a KA24E...Are they substantially different in head design form a DE?

OT: I saw a KA24E, carburetted at the North East championship SCCA races at Lime Rock in september. Car weighed 2100 pounds, made 260+ whp from a SOHC N/A caruburetted engine. Pretty impressive if you ask me. Plus, watching it RAPE 450 hp vettes on the track really really made me smile

[90lkn4swp]

i was taught that the engine stops producing power when the valves "float" this is what detirmines the max rpm, i would assume the bottom end would need to be worked on also to handle the higher rpms but mabye i have myself confused.

pasted from ka24de.com "The black nitrided is not a coating but a heat treatment that hardens the surface of the whole stainless steel valve"

from reading this i was under the impression that they use stainless steel valves and then heat treat them with black nitride if not korea must be doing more to me than i thought

[MarkEmark]

My bad, I thought the valves came as one or the other.

Damn, we gotta stop post-whoring, this has nothing to do with the topic

[90lkn4swp]

ive never seen the head of a de so i guess i should have put that in there since i am choosing to swap on in

[90lkn4swp]

yeah my fault i shouldnt have jumped in like that sorry just started posting

[1998cc]

What about if you have a big turbine and a small compressor? Wouldn't that spool up pretty well?

[Nathan]

The DE head is a shim on bucket design, ie: it has no rockers of any sort, the camshaft directly actuates the valve via the shim on bucket. Actually, it is basically the same setup as a CA with the exception of using a chain instead of a belt. Floating a valve is bad, it can bend the valve as well as ruining the spring and making it more prone to floating a valve at a lower rpm later or even breaking, which could lead to the valve actually falling into the cylinder (this is bad).

Edit: this is an example of the DE head setup:

[C-Kwik]

For any given turbo, having an A/R in the middle of the range of what is available for that compressor or turbine wheel is usually most efficient. A .96 A/R shouldn't be unreasonable. A .96 A/R is not available on the T3 from Garrett. It is available on a T4 turbine, so I will assume you are talking about a T4 turbine. Expect plenty of lag with a set-up like this. I run a T4 turbine with a .69 A/R. It's not bad at all. Those who want instant response will not like this turbine at all. Within the powerband, it responds well, but at lower RPM's it takes some time to spool up. A .96 A/R will respond slower. Unless you are getting into some rather large T-series turbos, I see no reason to run this large an A/R.

As far as the question about running a large turbine with a small compressor. Larger compressors move more air at a lower shaft speed. So a smaller compressor would need to spin faster. To spin a compressor faster, you need to have the turbine spin faster. A smaller compressor would only give a very small advantage over a larger one due to it's lighter weight, but since it's also moving less air for a given shaft speed, that would likely negate the benefits there or perhaps even make it worse.

[MarkEmark]

The DE head is a shim on bucket design, ie: it has no rockers of any sort, the camshaft directly actuates the valve via the shim on bucket. Actually, it is basically the same setup as a CA with the exception of using a chain instead of a belt. Floating a valve is bad, it can bend the valve as well as ruining the spring and making it more prone to floating a valve at a lower rpm later or even breaking, which could lead to the valve actually falling into the cylinder (this is bad).

Edit: this is an example of the DE head setup:

Thank you Nathan. The KADE DOES NOT have rockers of any sort. So for thos of you who think it does, it doesnt!

[90lkn4swp]

Im sorry if im incorrect since i cant go to my car and take off the valve cover to make sure but when it was off i remember it having rockers my car is a 90 ka24/E i know now that the DE does not have rockers but i still have to dissagre on the single cam i am quite sure it has rockers

[Nathan]

Yes, the E does have rockers. Don't be sorry, it's easy to see how you would think all KA's have rockers, but now you know one of the joys of the DE

[sil80drifter]

yes it does and they RULE

I can never make my mind up, whats better, one cam and rockers or two cams and no rockers, because Es have 12 valves, i.e. 24 springs (counting the internal ones) and 12 rockers. That's 36 moving parts. DE has 48 springs and no rockers (I believe the DE also has double springs at every valve, but if it doesn't then correct me). So the E has less moving parts which is always good, but then again it's one cam which does all the work, which makes it wear out faster than a cam which only does intake or exhaust. A dilemma to me. This is just talking about SOHC vs. DOHC cams and moving parts. I didn't mean to postwhore this into a DE versus E debate

sil80

[C-Kwik]

The DE has single valve springs(only 24). I don't remember seeing dual springs on the SOHC KA either. There's really no reason either KA would need dual valvespring set-ups.

Rockers have a larger mass than a shim-on-bucket system. Hydraulic valves are heavier than purely mechanical valves as well. While there are 4 fewer valves in a SOHC, the DOHC can breath better due to the larger vlave area. And this can be done at a lower lift than what is required of the SOHC to even attempt to match the DOHC's airflow. So take a lighter valve train with lower lift and you attain a system that doesn't need as stiff a valve spring, resulting in less friction, resulting in more power.

[sil80drifter]

Good points. The SOHC has dual springs, I can attest for that with 4 hours that it took me to get them off the head with an ineffective pepboys valve spring comrpessor. I don't know about needing duals or not, but I know that a fully built Nissan Motorsports NA SOHC KA, with a completely rebuilt/modified head/bottom end (all Nismo parts) that was used in their 240SX race cars back in the 90's was able to revv to 12k rpm and make very good power. They also tried using the DOHC in 91 when it came out, but then went back to SOHC for some reason. I want to be cynical and gloat "therefore SOHC must be better," but I really don't know why they went back to the SOHC. Perhaps for ease of maintainance, perhaps because they were getting out of that type of racing and didn't want to start tuning the DOHC when they already had a good SOHC available. Bu the SOHC was even put into an S14, similarly built and has done remarkably well. I really don't want an SOHC vs DOHC thing to go on here, just stating what I think may be of help when considering head design.

sil80

[red240ne]

yes, the SOHC does have dual valve springs, which confused the hell out of me the first time I popped the valve cover. I never understood why it did.

[Touchdown038]

So let me sum this up for those of us that aren't quite as experienced in this area:

The E head has rocker arms, which means the valve stem is directly connected to the end of the rocker arm opposite of the camshaft lobe. The valves open when the camshaft lobes approach the top.

The DE head has bucket-style lifters, which means the valve is opened by the lifter itself when the camshaft lobes are approaching the bottom.

Correct?

[sil80drifter]

Correct

sil80