expected more out of my tsp 408 247 heads and ms4
04-12-2013, 04:37 PM
#21
Positive theirs a difference in lengths and the only exhaust shop near me is arh so I don't think they'd be happy if I asked them to fab something up between their headers and kooks true duals. Also remember this is my daily driver not a race car, tsp told me this is the highest conpression I can run on 93 octane.
04-12-2013, 10:55 PM
#22
Well I didn't even say the exact compression as I don't remember, I'm going to call on monday and ask. Maybe ill just have arh fab up a nice true dual setup out the rear. I can't see it being better or worse then kooks and ill have them install a set of cutouts while its out.
04-13-2013, 10:31 AM
#23
Well I didn't even say the exact compression as I don't remember, I'm going to call on monday and ask. Maybe ill just have arh fab up a nice true dual setup out the rear. I can't see it being better or worse then kooks and ill have them install a set of cutouts while its out.
I always set my customers forged engine pump gas 93 octane engines up with at least 11.8:1 Static and 75% of the time I'm at 12.0:1-12.2:1. With the right camshaft and quench you can run these types of compression numbers all the time with great results and no knock. I also don't really like the camshaft profile for a 408 with a 247cc cylinder head on it. I know if you were to call up there and ask for Aaron he can get you straightened out. If you can run a 2" header, do it! You've got a stroker engine and it can utilize every bit of that 2" primary along with a 3.5" collector.
Scavenging during overlap doesn't just happen or occur in the cylinder/combustion chamber itself, scavenging starts in the primaries, then the collectors and lastly the x-pipe/y-pipe merge from there on back. If the exhaust isn't set-up properly scavenging can't efficiently take place causing a lack of torque which equals a lack of HP.
Compression also equals torque and can really serve to broaden the power curve. I think between your compression, camshaft and exhaust you're leaving at least 50rwhp on the table if not possibly more.
Things to do:
- Go to a 2"x3.5" header or a stepped 1x7/8"-2" header with a 3.5" collector.
- 3" or even oval 3.5" true duals with a QUALITY X MERGE!!! This is highly important as if the merge is inefficient the exhaust pulses will collide improperly and not allow power to continue to increase until the frequencies in the exhaust level out and change resonance from a rise in RPM.
- Possible camshaft change. If the new headers and exhaust do not net you what you're missing, you're still not happy or you just want more power you can pick up some power in that department as well.
Once you do this, you will have a much more efficient set-up and you'll be happier with the money you have spent on this engine and combo.
04-13-2013, 12:51 PM
#24
I spoke to jake one time and the second im not really sure but it def wasnt aron.. I told him flat out I want the baddest engine he can put together for my dd. I would have never picked a ms4 on my own. I'm definitly going to want a new cam just not right this second as I'm not rich lol. So I'm gonna go ahead and order kooks 2" headers and 3.5" true duals
04-13-2013, 03:31 PM
#26
530+ with just the supporting mods exhaust, lid, and maf would be nice. For now I'm going to just port my fast 92 and once I get the cash ill have mamo port a 102 for me and figure out the cam situation. I didn't realize kooks full exhaust was that expensive
05-15-2013, 11:18 AM
#32
On The Tree
Go with the plan in the above post and the headers with true duals. I think the heads are at least 10cc to large if not 20. That is hurting you. For heads that big you will need a cam in the high 240's to high 250's minimum to take advantage on a 408. You will also have to mill them pretty well to get the 12.0+ compression you are going to need to run that cam. A ported 92 will take you to 575+rw. It was proven on my 416. But the 102/100 won't hurt. I would ditch the MAF and so CLSD or COSIII but that is just me. MAF's have come a long way and may not be a restriction any more if you size it correctly. Don't be dissapointed in your numbers now. It just looks like a bad set up honestly. ARH and Kooks headers are almost carbon copies. Are you shure Kooks true duals won't bolt up?
He nailed what I was going to discuss.
Your combo dyno'd low because it is not an optimized setup. Don't cry. I've been there, as have thousands of stroker builders who listened to the wrong people with their parts selections.
The 2.12" intake valves of your PRC 247s are shrouded like hell with just 4.030" of bore. PRC 237s or even TFS 225s would be a much smarter choice.
I ran the same MS4 cam on my stroker and the torque/drivability was awesome but again, it is not optimized for your 408.
I currently run a 243/251 on LSL lobes and it is great thus far, but even now after all my research I wish I had changed the valve events a bit more.
PM me or post up here and let me know what your goals for the motor and the car are, and I will help accordingly.
Mine has not eclipsed Pray's numbers yet, but it made 531/487 SAE through cats and a 2.5" catback on pump gas, NA with only 4.005" of bore, so I know more than the average bear.
At the end of the day, sizing the heads appropriately to the bore, setting the valve events to the goals of the motor and the head flow/intake manifold setup, and controlling cylinder pressure...all add up to success of failure.
We're here to help if you're willing to listen.
-Michael
05-15-2013, 11:22 AM
#33
On The Tree
Bullet Racing also has some excellent sticks out there that make huge power with relatively small duration numbers.
