SR20 vs. KA24

[Guest tejas74260]

1.Everyone says they'd take the KA over the SR just because of the displacement. If you're a firm believer that displacement is the deciding factor' date=' then why would you take out the L28, or whichever motor your car had in it? Fact is, there's a lot more to the equation than displacement.

 

2.I've personally seen one KA over 500hp. It was awesome, but rare.

 

3.As far as the narrow power band for the street discussion goes, how many of you who complain about turbo lag have actually driven a car with a big laggy turbo, and say 400-500hp?

 

4.For me, it gave me better gas mileage on the street, because I wouldn't drive around boosting everywhere I went.

[/quote']

 

1. yes the KA has displacement than the sr...but the cylinder head design is much more advanced than the l series engines (4 valve, cross-flowing heads, DOHC, better spark plug placement.)

 

2. whats wrong with doing something not a lot of people do? isnt that what hybridz is all about?

 

3. i have rode in my friends 86 grand national that has a HUGE turbo. yes...once you hit boost its awesome...but youre also passing into the "reckless driving" area that you can be arrested for, in his case almost triple-digit speeds (and thats in a 3700lb tank). i'm looking more for instant response whenever i feel like pressing the gas.

 

4.gas mileage is definetly not a concern...this is the car that im learning and honing my mechanical skills on...and its only a weekend fun car.

 

A lot of this discussion involves personal preference.....which is why i'm not really swayed either way. ive been plotting compressor maps for a while and ive matched a turbo (t3/t04e 50 trim with .48 a/r turbine) that will spool well at about 3k rpm (hitting about 70% efficiency). either way, this could go on forever...so i think i'm gonna go with what seems better for my wants and go with the KA. thanks for the help guys...

 

if you can help me answer my intercooler question i had above that'd be awesome. thanks

 

Mark

[MrWOT]

You've only got 2000rpm at 260hp?

 

Maybe it needs tuning?

 

An SR20DET at that power level can run for a few thousand RPM in power.

 

That's wheel horsepower, in an awd car and it hits full boost at about 3200rpm but the secondary butterflys only open at about 4000, going to change that soon though.

[Hugh]

Either way... that sounds like a narrow power band.

 

(and I only refer to wheel horsepower ratings as well)

 

 

Here's my last dyno sheet. It was in japan, so its in PS, 399.8rwps = 395rwhp.

 

video: right click and save as

http://66.194.152.253/%7evideof6/zeroyonvideos/HughDyno399.mpg

[MrWOT]

So you make about 267ft/lbs, I take it you're not done tuning then? I would have figured higher for the t67 Heck, I make almost 279ft/lbs on the stock supra CT-26 at 17psi/4200rpm (supra has a larger exhaust housing then the stock celica one). 9.0:1 I'm guessing, and is that with stock cams? (sorry just curious, trying to gather data for comparison )

[karay240]

Comparing the torque out put of a 2 liter I-4 and 3 liter I-6 is like comparing apples & oranges, though. . . That's 50% more displacement than the SR. If you want to be fair, how about comparing the SR to the 3S.

 

Another tid-bit to think of when comparing figures b/w US and JP. . . actually any two cars is the fuel used.

 

The Japanese pump gas, along w/ the higher price, has a higher octane than US pump gas. It's not like race gas or anything like that, but higher by a couple digits--translates to more safe power.

 

Kenny

http://www.rbmotoring.com

[MrWOT]

Comparing the torque out put of a 2 liter I-4 and 3 liter I-6 is like comparing apples & oranges' date=' though. . . That's 50% more displacement than the SR. If you want to be fair, how about comparing the SR to the 3S.

 

Another tid-bit to think of when comparing figures b/w US and JP. . . actually any two cars is the fuel used.

 

The Japanese pump gas, along w/ the higher price, has a higher octane than US pump gas. It's not like race gas or anything like that, but higher by a couple digits--translates to more safe power.

 

Kenny

http://www.rbmotoring.com[/quote']

 

Did I miss something? Who's using a 3L I6?

[karay240]

You were talking about the 3S. . . my bad, I saw supra and CT and I thought 7M. . . nevermind.

 

Another thing to note is that the 3S is inherently a torqier motor than the SR. If done right the 3S can have more torque than hp until about 400hp. Toyotas, in general, seem to be made that way. That's why I was my 1st candidate for the hybrid, but I'm too poor

 

Anyway, sorry for the screw-up/confuision

 

Kenny

[Hugh]

Actually, if you look back at the sheet, my torque is listed in Kg. Converted to ft/lbs, its 362ft/lbs. Thats a whole lotta torque for stock internal 2.0 liter with 395rwhp. That dyno sheet is really hard to read because the operator didn't bother to balance the curves on the same scale.

 

This was my old turbo setup, which was a AR.50 HKS exhaust housing with an O-trim T4 wheel, and an HKS T300S compressor (slightly smaller than a 60-1 T04S compressor) I built it from junk used parts with Garrett rebuild bearings and seals. This thing really was pretty ghetto.

 

That was also a rough tune, and I did get more power out of it later on. I went to larger compressor, and ran higher boost. I never got it back on the dyno, because I was getting ready to return to the states.

 

I sold the turbo kit and I'm now getting ready to put together the next setup, the Full-Race kit with their manifold (its a work of art) and their T3/T67, which is like an HKS T04R with a T3 stage 5 exhaust on it in an AR.63 housing. This turbo makes ~600rwhp at 24psi. It also has a broader power band and with cams, will rip past 8000rpm most likely.

 

Once my container comes in from Japan, I will put it together and get to tuning... and start posting dyno sheets again.

[karay240]

Nice, keep up the good work, and keep us posted on your progress

 

I'm going to go pick up my donor car next week. . . I can't wait 'til I FINALLY start working on mine. Yea, I'm going to have to wait at least a month or two, but when it arrives. . .

 

kenny

http://www.rbmotoring.com

[Nismo280zEd]

Anybody have a manual 4banger they want to get rid of? Looking for a cheap daily driver.

-Ed

[Jsquared]

it's amazing how many people like to comment about SR vs. KA, and none of them have experience with either one. I would take Hugh's info over most everyone else here. The KA24DE-T most certainly does NOT "suck" as one ill-informed user put it. 630wHP with just rods/pistons (bigass turbo/injectors and GOOD tuning... no headwork! just cams...) on a KA24DET, and I'm sure everyone by now should know that four people in the US have knocked down over 530wHP on STOCK bottom-end SR20DETs. It's harder to make an argument for a KA24DE-T on a car that didn't come with a KA (which would obviously make the to-do list a bit simpler ), but it's still a darn good engine. It can spool a turbo quicker than the SR, and it makes more torque, and parts are a bit easier to find.

 

Of course, the SR is about 50 lbs lighter, with a bit of that weight further back (with stock exhaust manifold and the like), and the SR is ~140+ lbs lighter than the RB20/25 engines. The SR is more stout to begin with, but all you really need to do on the KA is a set of pistons... unless you want more than 550wHP, in which case you might want to see a shrink before you start turning wrenches hehehe. And either option will take noticeable weight off the front of an old-school Z-car, which will help overall power-to-weight and will shift some of the distribution towards the rear. Of course, then you're stuck with the not-so-nice 4-banger exhaust noise... my SR doesn't sound that bad for a 4-banger, but it's certainly no inline-6.