My New Engine Build + Harrop

[bolus]

water injection is the simpleast, easiest, least expensive and safest approach to cooling. 

[Heywood-Yablowme]

Bolus is right.Injecting water is the easy and inexpensive way to lessen the possibility of detonation due to excessive intake air temps. The Harrop will not heat the air as much as the stock Eaton. I am not expecting to have to do anything but water injection with the Harrop. I do believe it is capable of 300whp. comfortably, but not 400.  In all honesty,I don't think the Atom needs more than 300whp.  (did I just say that????)  An honest 300whp Atom with a nice fat power band would make a dandy track car,in my eyes.  However,I do lust for a 500hp Atom, as well

[NormLarson]

This is a quote from the CobaltSS.net forums under "Wheres the TVS dynos":

"M88ArRamadi 407 whp, 387 wtq I, TB, WI, TVS, 2.75, HE, DU, 60's, RS, FI, H, CD, E, RG (other mods: 10.5:1 diamond pistons, ported head)

just for information's sake, here's M88ArRamadi's tvs numbers. He put out more tq than paul (blackg85ss) and he did a 421whp pull, which is when the motor blew due to massive knock."

I do not profess to know what all the hieroglyphics mean, but, obviously the TVS (Harrop) can put out some power and still be a supercharged power curve.  It was definitely pushed to far ...  Seventh post http://www.cobaltss.net/forums/showthread.php?t=160935

Major differences from my build that I see 10.5:1 vs. 9.5:1 and a 2.75" vs. a 3.1" pulley, oh and a ported head

[Heywood-Yablowme]

Well,yes,the Harrop can be...pushed to 400whp,however...at those boost levels,you are running into the same problems as the stock Eaton; HEAT.  The Harrop is better for sure,but not the answer if you want 400whp and a motor that will stay together. I see the Harrop as a great way to get to 300whp with the stock engine. With mods...maybe high 300 numbers.  But,if you want 400whp and be able to track the car...I see only the turbo as the answer. More complicated than just bolting on a replacement blower,but it all depends on what you need.

[NormLarson]

I agree, but I do want to be in the mid 300's and I am going to port the head for efficiency.   I posted that to show that some are going higher.  I will not be able to go that high anyway with oxygenated fuel ...

[bolus]

Norm, I'd recommend you try out the car before you spend any more money on porting.  First, the car should scare the crap out of you.  Second, the head flows pretty damn good at stock and I doubt you'll drive the car and wish you could get a few more HP. 

[Heywood-Yablowme]

I know a 300-350whp Atom will be fine for my needs,with better tires,brakes etc..  

450+ is for the real wackos           
 

[maverick1]

[quote="Curator"]
I know a 300-350whp Atom will be fine for my needs,with better tires,brakes etc..  

450+ is for the real wackos             ;D
 
[/quote]
You mean CalScot....
cheers

[Heywood-Yablowme]

I mean anyone over 450whp

[NormLarson]

[quote="bolus"]
Norm, I'd recommend you try out the car before you spend any more money on porting.  First, the car should scare the crap out of you.  Second, the head flows pretty damn good at stock and I doubt you'll drive the car and wish you could get a few more HP. 
[/quote]

I beg to differ on this one.  A ported head does make a difference, it cleans the airflow at higher boost and the air has less resistance and heat creation.  We will see when I flow it, I have a friend that ports heads for a living.  I will post the before and after flow numbers.  The guys on the Cobalt forums say that they are getting significant improvement from porting.  Again, I do not think that I am necessarily looking for the power from the port, not that it is bad, just more efficiency.

[Heywood-Yablowme]

With forced induction,porting gains are a much smaller percentage.

[bolus]

I guess it depends on what you would consider an improvement.  Believe me, when doing full throttle second gear pulls when we were tuning I was holding on for my life thinking 'oh god, I created a monster'  and I was running half the boost that the engine could take. 

To me, if you went from'scare the sh1t out of you' to 'really scare the sh1t out of you'  it is really hard to tell there is improvement

Believe me, I'm all for upgrading for upgrading sake.  But port jobs are pretty expensive and you may not want to bother spending that money once you drive the car.    Or leave it for a future upgrade after a year or so when you get more used to the power. 

If your friend is going to do it for free, then obviously go for it. 

[silver]

I think maybe........Norm's point is that he'll sleep better at night knowing he did what he could to get the most out of his Ecotec.

[bolus]

it is a tough to know when to stop.  running out of money is a good place to stop.  but if that's not the limit where do you stop?  new crank? sleeves? staking the head so it will handle 1000hp?  applying coating to all the engine components? methanol injection, converting to methanol fuel?  ......

[McFred]

[quote="bolus"]water injection is the simpleast, easiest, least expensive and safest approach to cooling.  [/quote]

...except for not needing it in the first place.