mountainbiker2

Help me decide. I have a 99 Corvette with a Comp cam 220/224 581 114, Kooks headers, LS6 intake and stock TB. Stock LS1 heads. After waiting 4 months to save money for heads, I was always going to buy AFR. Now ET comes out and my engine builder is a dealer for them. They also sell AFR. My car is used for Autocross and Road Racing. Lot's of times, I'm very low in the RPM's coming out of corners.
I'm going to leave everthing as is, just change the heads. The ET's will cost about $500 more for the whole job. They are not CARB legal either. I live in California.
So I'm asking is it worth the extra $500? Is it even any better then AFR heads?
What do you guys think?
I'm having the heads installed Nov. 14th.

Thanks.
Steve

Brandon Boomhauer

iTrader: (10)

why are you in very low rpms coming out of the corner/

why not downshift?

check the dyno section, there was a recent post from a switch from afr to et heads on a small cam. Read the whole thread though, there are different variables to come into play. However I think ET's will be my head choice when money allows.

Patrick G

iTrader: (14)

While the initial results of the ET heads look very promising, you absolutely can't go wrong with the "proven" performance (especially at low and mid range) of the AFR 205s. Don't know if the ET heads are worth the extra bread or not. Time and more tests will tell.

mountainbiker2

[QUOTE=Brandon]why are you in very low rpms coming out of the corner/

why not downshift?

In autocross it would take to much time to downshift into first then right back to second. Also some turns on big tracks you might have to shift mid- corner which is bad, so you have to go with the higher gear.
I'll check out the dyno run forum.

Thanks.
Steve

JakeFusion

iTrader: (7)

Heel-Toe technique...

And get whichever is cheaper from your tuner.

alchemistz06

ET heads outflow the AFR everywhere. You will get prolly another 20rwhp running ETP heads.

Good Doctor

iTrader: (1)

Peak numbers are not always the full story, power under curve is very important, most importantly, in this application.

vettenuts

iTrader: (4)

I am looking at the same thing right now. Not sure if the ET heads are available in anything but the 58 cc combustion chamber, I think they are but their web site doesn't reflect this. I really like the AFR's myself, and I too am looking for low end grunt so I will be watching the dyno curves to see how things fare.


The GMPP heads flows pretty much the same as the ET's (I have plotted all the flow data) but I don't know how they hold up for low end torque since the intake port is 244 cc.

Craig@ETPerformance

iTrader: (1)

Our heads are available in anything from a 35 - 72 cc chamber sizes. Peak numbers are nice, but it is true for what you are doing you will need low end to mid range power. A gear change can solve a whole bunch in a roadrace/ autocross application.

Craig@ETPerformance

iTrader: (1)

Our heads do outflow a 205 on the flow bench. It is a new product, thats what is great about the free world.

Facts are Facts, everyone that has run our new heads have made great power and the same with AFR heads too. Lets be real about this, there is more to come and this debate will continue for a long time.

vettenuts

iTrader: (4)

I am curious about this, do you cast a certain size and then CNC out the rest to a spec or is milling involved?

Also, for straight bolt on is the 15 degree a better option? How does the 11 degree affect the valve train geometry if at all?

Thanks for any information, trying to get up to speed on this new product.

Brandon Boomhauer

iTrader: (10)

I believe they cnc to get the chamber, i doubt they'd mill the heads to do that.

The heads can use stock rocker arms, with the correct stand.

Oh, and post #s dont mean jack ****. i have near 6k posts, but Craig has 81. Does that mean I know more than him? I highly doubt that.

Craig@ETPerformance

iTrader: (1)

Our heads as cast are maybe 10cc if that. We CNC them which brings them up to roughly 62cc & 72cc. Getting them down to 35cc will require milling and milling to the manifold to get it to fit.

Same effort will go into the install. Things are moved in our heads, we require for a factory rocker arm to use our rocker stand. All that is left to have perfect geometry is the correct length pushrod. If anyone has anymore questions just fire away.

DavidNJ

This is a daily driver used at the track. If you are autocrossing with aftermarket heads, you are in a modified class, where it is unlikely an LSx-based anything will be that competitive (too wide and too heavy). Similarly, the competitive road racing classes have rules that usually require stock heads (ok, maybe not ALMS).

So, the questions are two fold. First, is the CARB important or will you be able to pass with a non-CARB modificiation?

Second, is a cylinder head really the issue or would the money be better spent on shocks, springs, and tires. For oval track racing I judge every thing in terms of tires ($600/set). It is amazing how many things don't measure up. For both road racing and autocrossing a set (or multiple sets) of rebuildable mono-tube shocks. Many prefer the externally adjustable which can easily run $4-7k/set for 3-4 way adjustments. Add in tuning with different shims, pistons, and pressures, and you need to ask, is the cylinder head the next thing to change.

On the street, you probably couldn't tell the difference.

vettenuts

iTrader: (4)

Thanks for the information. I am running Crane adjustable rockers, would these setup as they would on a standard LS1 head?

Nate_Taufer

iTrader: (1)

If you're worried about ETP heads not performing just search around on google for their other non Gen III heads. People act like ET Performance just showed up a few months ago and said okay we are the shizz. Theyve been around for quite a while. Hell W2W loves ETP because of proven gains switching from ported ls6 heads to the ETP ported 5.7L heads.

Nate

Tony Mamo @ AFR

iTrader: (13)

Guys...

I posted this paragragh or two in another thread concerning the latest AFR debate but thought it was worth sharing here as well for those who might have missed it.

"The initial results from a few ET head installs certainly look promising. There CNC work looks very good (on par with our own quality) and lets not forget they have the advantage of a much shallower valve angle and a raised exhaust port which always enhances airflow and ultimately power output. Is the ET 215 really worth a significant power advantage over an AFR 205 nine times out of ten??....Anybody's guess and the bottom line is we will have to wait and see as more results make it to this website and others. I take my hat off to ET as the product certainly looks good and the results promising, but I think we need to see more of both to determine what the gains (or losses) will stack up to over the long haul. I would still choose a 205 for a street/strip car that wanted to place an emphasis on the "street side" of that equation, as the smaller port is still going to get the nod for part throttle and fuel economy, and we all know the proven power potential even with smaller cams and the right AFR 205 set-up.

Don't forget that AFR set their sites on building an emissions legal direct replacement performance head (all geometry exactly like stock), and within those parameters we have certainly hit a homerun. Are we sitting on our hands now that project is almost complete (awaiting the release of the small chamber 225)?? I will leave that to your imagination...Don't throw away all your "blue pills" just yet....

Competition is a good thing and technology marches on....Exciting times for sure."

Also, as Craig previously mentioned....I'm sure this comparison will rage on for quite some time as more and more ET combinations find their way to these pages (as well as additional AFR headed engines as well). With a larger cross section of information to evaluate, it should be alot easier to approximate or guess how they fare when compared to AFR's current offerings.

There has never been a better time to be an SBC enthusiast (Ford and Mopar fans aren't doing to bad either)...Let's all enjoy it before the government has everyone driving electric cars while the rest of us drive our Hot-Rods like "Mad Max" following fuel tankers thru the desert

Regards to all,
Tony M.

Brandon Boomhauer

iTrader: (10)

Very true, I'll when that day comes.

mountainbiker2

Yes David CARB is somewhat important. My car needs to be smog every 2 years. This is just one more thing I would not have to worry about. I already have LT headers that are not CARB legal. Most smog shops overlook this, because they don't know what they are looking at.
My car in autocross is already in the modified class (SM2) and the Corvettes usually win. In fact I don't think one has lost yet that I have seen. When I go to Willow Springs in California it's just for fun. No times, just running around on the track with 20 other drivers. I'm a instructor too. This is the last thing on my list of mods. Suspension,Alignment, Coolers, Wider wheels, tires all done. Your right when it comes time to spend money on mods, I first think about tires I have to buy every 3 months, rotors, brake pads, ect.

Thanks for the comments.
Looks like I'm going with AFR.
When it gets done, I'll post the results. Should be in 2 weeks.

Steve
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vettenuts

iTrader: (4)

Whose cam are you running? It is just slightly larger than mine so I will be very interested in your results and how it pulls down low