Car is a blast to drive and runs like a scalded dog but just wonder why it's done at 6k??? Power does carry farther out nicely though and I love the tq. curve. Just wondering what might be in if it if peaked 4-5 HUNDRED higher??... Here we go...


HKE 403 SB (Callies, Wiseco etc..)
11.2 SCR
TFS 220 "as cast" worked over by TEA
EPS 238/ 250 .613/.603 112+2
Ported 90/90
100mm MAF
104mm lid
ARH 1 3/4 with catted Y
Hooker CB

I realize the exhaust is my biggest restiction but is that what is making it lay over at 6K???

 

Install a cutout and see what happens.

Also, how come you didn't go with a fast 102? I'm sure that could free up some hp all over the place.

 

I wonder what would happen if you stepped up to a fast 102 and put some 1 7/8 headers on the car. However I don't think that will determine the peak of your curves.

 

Wow... wish I had that torque curve. Over 400 ft lbs for most of the RPM range.

 

Take the cats off and install a cutout to see what happens. Guys are acting like no one has made good power with anything but a Fast 102 lately. Kinda funny since the fast 102 is a new intake and 40x cube LSx engines have been making great power for years without them. Who ported your fast and do you know how much was actually done to it? 49 IVC point wont really turn a ton of rpm on a 403 most certainly not 4-5k more like you are looking for (10,000-11,000 rpm!!?)

It might be worth running the car open header on the dyno to see if it picks up much if you are curious.

 

Haha I meant 4-5 HUNDRED but I think everybody knew that. Yeah I know a cutout would help but I don't think it will make it peak higher but would pick up 10-12 hp I bet...

 

Did you advance the cam? Could it have been ground with extra advance by mistake?

My cam was supposed to be 0* but ended up being +3* so my peak is 300-400 rpm sooner

 

Curious why the large 12° split? I have seen great results with cams in the 240's duration. I would think a 242/248 114+2 would extend your peak hp to 6300 rpm and provide slightly better drivabilty.
I'm no expert, just thinking out loud

 

Honestly I am thinking along these lines too....

I mean maybe I should just do a cutout and scare 500 and be happy I don't have to spin it to the moon to make good power.....

 

Lets see, my 418ci motor has a bigger split than that with a Super Vic and pulls clean to 6,900.. I do however think the cam is small and you don't have the valve events set right to pull higher with your cubic inches. I also think the longer runner of the fast intake is also hurting RPM. But, both of these are helping you down low.

Here are the things I see with the cam:
You only have 16* of overlap / I have 34.5* of overlap
You don't have enough duration to get that with out a 105 lsa

But I don't think this is hurting you as far as RPM goes compared to the intake. Through performance trends engine analyzer using my motor (with my heads since I know nothing about your flow numbers and runner volume) putting my cam profile picks power up through the full curve, but, the curve doesn't change (at least as far as peak rpm).

The long runner of the intake is hurting you more than the cam. Changing the intake with both my cam and your current cam does move peak RPM up.


Is performance trends perfect, no. But has it almost nailed many combos that I have checked? Yes.. With very good info, I have been with in 2% of most engine dynos with it.

 

I have exactly same power curve lot's of tq but peak at 5900-6000 and don't carry well drops after 6200

but similuar setup i have but whith 1 7/8 kooks and Cutouts and 92int /90tb

been thinking it could involve my cam somehow

248.254 615.622 @114

would love to see it peak around 6500rpm

good luck though

Baezi

 

I had too small of an exhaust on one of my dyno runs, crappy LM2, and it was nearly flat after the early peak.

 

I agree with the above. The cam is small for what you are looking for and IMHO the valve events are wrong as also mentioned.

 

I dont know why you're complaining about it, it peaks at 6K. The cubes are simply taming the cam. I'm sure it will perform well and be a blast to drive.

 

x2 Agreed!

 

if it was my car,i would definately switch to the bigger headers.IMO,you would pick up power over most of the powerband and probably carry your peak a little higher.have you talked to HKE about this?

 

I think its 1) the 112 and 2) the excessive exhaust duration.
A 112 lobe is a harder hitter, but it also dies quicker--less cylinder pressure on top. Plus, you are scavenging the hell out of the exhaust. As velocity increases, I would guess you are sucking out more and more of the intake charge in the exhaust. Play with different cams.

 

Well I am gonna call RPM tomorrow and find out what my kpa is to see if it is an intake restriction and go from there. The I pipe in the catback is 3" so I think a cutout will help but who knows how much??? Then I will go from there...

03EBZ06 I have thought about this too.. Cam was supposed to be on a 113 but was cut on a 112. Heads flowed 322/254 so they are strong on the exhaust side ( I wondered about the wide split too) but how can I have a known exhaust restriction (small headers, I pipe) and also be over scavenging???

I will keep this thread updated as we figure this out...

 

If the cam company cut it on a 112+2 all you had to do was pull out the ol degree wheel and just retard the cam 1 degree, 113+2... The shop that installed it could have done that.....



Bozz

 

If he retards the cam 1 degree, its now a 112+1. But that logic is flawed too because the cam gears only come with sprockets that adv/ret by 2 crankshaft degrees. The ICL for a 112+2 is at 110, so the new ICL for a 1 degree retard is 111, not 113. If the ICL was 113, he would be at 112-1.