Built KA

[TrunkMonkey]

But we're talking about building a street car. One that I can drive to work.

My point is this and only this, I'm done saying this over and friggin over again. If you want a high hp daily driver with boost then you should lower your CR because boost gives more power. Period, no if, ands or buts involved.

i'm gonna correct this. lowering your compression ratio allows you to run more boost safely. a lower compression ratio is a deterent against detonation and that's all. you don't need it to make power.

people are so quick to drop there compression ratio so they can run alot of boost, but why make X amount of hp at 15psi when you can make the same at 12?

back to what started this discussion...dropping the compression on a 9.5:1 engine is a waste of time.

-demetrius

[syka24et]

There was a link on overboost about a turbo KA that was running 10:1 compression and I think a 9 pounds, mild engine build and making close to 300hp. Personally, the only way I would build a high compression turbo motor would be for say 250-275 highly tuned. The car would have power in almost everypart of the rpm band. That would be a ball to drive. But for peak power and racing you can't beat a lower compression.

[WDRacing]

I really wish you people would read my posts. Forced induction makes more power then raising the compression...period.

So guess what, if you lower your compression, you can raise the amount of boost therefore making more power...period.

I'm not arguing anymore

[TrunkMonkey]

There was a link on overboost about a turbo KA that was running 10:1 compression and I think a 9 pounds, mild engine build and making close to 300hp. Personally, the only way I would build a high compression turbo motor would be for say 250-275 highly tuned. The car would have power in almost everypart of the rpm band. That would be a ball to drive.

let me clarify myself just in case i'm misleading anyone. i'm not saying that people should raise their compression. i'm saying that people shouldn't lower it. even corky bell discourages this in maximum boost. 10:1 compression isn't considered high anymore. as i've stated before, this is what most late models cars have anyways.

But for peak power and racing you can't beat a lower compression.

yeah, if you're trying to build a 400+ hp car. since you're going to be lagging anyway why not give yourself the add insurance up top.

dropping your compression doesn't guarantee you more hp. yes, you can run more boost, but a car with a higher compressoin ratio will always produce the same hp #s with less boost.

-demetrius

[TrunkMonkey]

I really wish you people would read my posts.

and you posting something is supposed to mean what?

Forced induction makes more power then raising the compression...period.

So guess what, if you lower your compression, you can raise the amount of boost therefore making more power...period.

there's a post on FA by Greaser, a very well accomplished experienced tuner, who had a friend who was boosting 16psi at stock compression. his friend wanted to lower his compression so he could "make more power". when he did, he made less power at 16psi than he did before. so his friend would have to run more boost just to reach the same level he was at to begin with. Greaser himself even raised the compression on his SR and guess what...he's making more power at the same boost levels.

if no one believes me, then do a search by username on FA. type in Greaser and do some digging. maybe later i'll find and post the actual links.

I'm not arguing anymore

arguing? hell, i'm having fun.

-demetrius

[WDRacing]

DEMCJ, You and I are agreeing on the same thing but arguing different points. We both know a higher CR say 10/1 will make more power at say 8 psi then a 8/1 motor.

What I'm saying is that when you drop the CR it allows you to run more boost. Which will generate more hp. I know you have to add boost, but thats my hole point. I will always add the max safe boost level to all my cars. Boost is where the power is.

Thats the way I tune my cars, basically everything is tuned around turbo and as much boost as possible. Now if I have a stock bottom end. I'm not about to run 25 psi, but I will increase the boost till she starts to indicate knock then back her off a bit.

What I meant by "I wish people would read my posts" was in my second post, I explained my theory, or rather one taught to me, about how each psi will allow for greater amount of hp then per point of compression. I wasn't saying I'm god, although I do hold myself pretty high sometimes. But I'm vane and I've accepted it...

I've also been in a real bad mood lately, I blew up my Honda. Then 2 days later I had 2 flats and a dead battery in my Pajero(Montero). I feel better now though, I just bought a MR2t.

WD

[WDRacing]

Structure, IMHO, you should lower your CR to 8.5/1 so you can add more boost. I don't think you'll have to worry to much about low end grunt do to the KA's long stroke. But thats just what i would do in your shoes. If I was building the engine I'd keep the stock CR and add alcohol to anything over 15 psi to avoid detonation. Then you'll be making mad power. Don't let the word alcohol bother you. The kits nowadays are easy to install and tune. It helped me run 28psi on a stock bottom end RB20. I don't know of anyone that has done that for an extended amount of time, on the RB20 that is.

But either way you'll make good power.

WD

[Structure240sx]

yea i was intimidated when all that alcohol was mentioned. sorry for not posting i was away on vaction gettint o know alky better. i think it was u that worte that u had the alcohol set to kick in at boost how did u set it up to do that

[WDRacing]

The kit i have is comes with a completely user adjustable module that you mount inside the car. You can adjust the volume of alcohol injected aswell as the boost the pump turns on at. It also has a low level light so you don't run out. The kit comes from SMC Enterprises...Just type in SMC alcohol injection in Yahoo, you should find it.

WD

[matt0941]

http://www.geocities.com/rad87....html

$350, and it doesn't look that complicated at all

[C-Kwik]

I'm all for Alcohol injection as a good way to increase boost, but personally, I want a car that I only need to fill one tank with. I'd rather build my motor to be used strictly on the fuel I can obtain most easily. And even with this limitation, I'm pretty confident I can make more than 300 WHP once I can deliver the necessary amounts of fuel for it. But to all their own. For those with easier access to race gas, you can also use a multi-fuel set-up where it injects race gas as the secondary fuel. Don Nimi built an Audi like this, and he took me for a ride....AWD and 300+ HP is a whole lot of fun, even in the Vancouver rain.

[WDRacing]

I just used my alcohol when I was racing on the weekends. I stayed at low boost most of the time. Especially since my car lagged till 4200 and didn't hit full boost till 5300 or so. So I was usually hauling *** when I needed the alcohol on.

WD