Jeff 96 SS

Well as always we had problems trying to tune the car. The day started out with a miss on the right side so we decided to pull a couple plugs they didn't look bad so we tried another pull this time the inlet hose to the intercooler blew off. this is not good for the plugs as the maf was reading extremely high numbers and the engine isn't getting much air but the computer dumps tons of fuel in so we decided to change all the plugs. Keep in mind that evertime something happened we had to unstrap it and jack it up ohh about 20 times during the day. We start the car up with its new plugs and it sure sounded funny HMM somebody swapped a pair of plug wires no biggie but it sure is scary to hear your engine making funny noises. So now were ready for the first real pull so we start it up to let it warm up about a minute later it just dies we all look at each-other some seriously strange looks on everyone's face and nobody says a word for maybe ten seconds. Try to start the car fuel pump isn't coming on well it turned out it was the relay pop in a new one no problem starts up. Now first real pull miss is gone new plugs fixed that but something wasn't good so we looked through the data and Ohh no the fuel pressure starts breaking up a bit at 4500 and drops like a rock about 5400. How can that be I bought the biggest damn pump you can buy well it seems I got a bad one it wont hold high pressure for very long. we troubleshot the pump for a couple hours tried everything to make it work at high pressure but it just wouldn't do it. We almost gave up at this point but decided to turn the fuel pressure way down and let the injectors do the work the pump was barely able to keep up but we managed to get enough fuel through my 75# injectors to feed the engine. we only made about five actual tuning runs mainly because I need to get that pump fixed and do the tuning the right way. The numbers ended up being 554RWHP at 5750 560RWTQ at 4700 their is probably a little more in it with a good fuel pump but I definitely need to figure out what to do next to reach my goal of 700+RWHP. I will probably be upping the boost a bit I was seeing 12#s at 5800 and looking for some bigger rockers that will work on this car. I don't feel like doing a cam swap as that appears to be what's killing the power evidently a 224 236 114lsa cam is to small for a 396. OK does anybody make a 1.7 rocker that will fit our cars?


Jeff
96 SS BLOWN
96 TA 396 D1

1LEThumper

I believe T&D or Jessel will make you a set of shaft mounts in any ratio you want.


I wouldn't worry about the numbers so much right now as you are just starting with the car. A lot can change once everything is figured out and tuning is done. I don't know if you will hit 700 with that combo. Either way its going to be a handful

Highlander

Exactly... my first dyno run was a 393@ 5psi and boy was I dissapointed... Now I am in the 600rwhp@10psi range with a bad impeller.. I fixed the impeller and I gained about 1.5psi boost.. so I should be in a good power range... I bet an rx7 turbo II that pumped 590 and made 10.5@131mph, so... you will get there... tunning.. tunning tunning.. patience...

IDOXLR8

If you are trying to get more power out of the car then I would recommend going with a solid intake pipe (get the largest filter you possible can). I also would recommend going with an SD concepts spring loaded tensioner.

texlurch

In answer to your earlier question, yes they do make 1.7 RR that bolt on and are supposed to clear stock valve covers. A company called Scorpion makes them. Scroll all the way to the right in the pic in the link...

Scorpion rockers

Jeff 96 SS

I just ordered a new cam 236 242 115 LSA. I'm convinced that my current cam is to small but that will be a winter project I still want to tune this thing for all its worth before I put in the new cam. I also included engine specs below. What do you all think of my new Cam?


4-bolt main LT4 block
Lunati 4340 forged crankshaft
JE Custom Pistons 9to1 compression
Lunati 5.85" Pro Mod Rods
CC R-Series Lifters
Custom CC grind Camshaft 224 236 114lsa
ARP Block stud kit - 4-bolt mains
ARP Head stud kit
Canton Oil Pan and Pickup
O-Ring block - Receiver groove
Melling M55A Oil Pump
Comp Cams double-roller timing chain
Trick Flow Push Rods
SCE Copper LT1 head gaskets
Custom ported AFR LT1 heads - 62cc chamber - O-rings
BBK 1000 CFM 58mm throttle body
Long tubes
Mufflex y-pipe
4inch Mufflex
ATI D1 Supercharger 3-core intercooler 15PSI@6400
Mezeire Electric Water Pump
Mufflex Custom Blower Intake Custom Fuel System:

Aeromotive Eliminator fuel pump
Paxton Boost Sensitive Fuel Pressure Regulator
Stainless Steel braided -10 fuel feed lines
Stainless Steel braided -6 return lines
Custom modified fuel rail
75# injectors LJs Impeadance converter

rskrause

You need more boost and you need to rev it higher to see anywhere near 700rwhp. Of course, you need enough pump to keep up with the injectors at higher boost.

Rich Krause

INTMD8

IMO, your current cam is not a restriction.

Another thing to consider is that with the higher amount of overlap with the cam you ordered (9 deg @.050 vs 2deg of your old cam), you will be placing more demand on your fuel system at the same given HP level.

Highlander

How much are you planning on reving?? i think the 224/236 cam is all you need for now.. maybe the high lift version of the XE cam would be a good idea.. ANyways reving the hell out of a 3.85 stroke is not a good idea for longetivity and for instant reliability.. You have top notch bottom end, but still 700rwhp is not an easy thing to achieve nor it is impossible given the bigger supercharger, nor it leaves you with enough room to gamble with something going wrong.. specially when you have o-ringed block and heads plus copper gasket... you have no "fuse". I think injectors might be a tad small unless you increase fuel pressure...

Remember that from 500-600 is a lot easier than 600-700, besides, is this for the street?

I also think the rod length is too big and I think you have a thinner piston, something to be aware of... In any case... Tune with this cam as i believe is the correct size for 6200rpm max... RSkrause, be sure correct me if im wrong

96vortechSS

I also think your current cam will make more power than the one you just ordered. With your new cam although the lsa is good for a blower it has too much valve overlap as James also said. You'll be blowing your boost right out the header. There are guys that have made over 600rwhp with the cc 218/230 .528/.536 114lsa camshaft without dfi. Who ported your heads?

rskrause

In general, yes. But a lot depends on how the blower is setup. You certainly may not see peak power until 6,400-6,500 if the boost is still rising (i.e. you haven't maxed out the blower). But it sounds like he is running out of fuel, and until that's fixed it shouldn't be revved higher.

Also, you are correct that a long stroke motor and super high revs aren't compatible with longevity. But there's reason no to set it up for peak power at 6,500rpm or so, especially since (I asssume) he won't see this rpm very often.

And 700rwhp is a lot, as you said. You will need good heads, good exhaust, lots of boost for this kind of hp. 12psi is definitely not enough. No matter what, he won't see 700rwhp except under absolutely perfect conditions - fresh motor, plugs, wires, perfect tune, low density altitude. Mid 600's is more realistic.

Rich Krause

IDOXLR8

To give you an example I made 705 rwhp with a 224/236 cam on a 113ls. The above power was made with 14psi (ATI F1). My setup still had alot left in it but my biggest retriction was the twin intercoolers and trying to keep intercooler hoses from popping off. My heads are ported stock heads. I am running 83 lb injectors at an 80% duty cycle.

Jeff 96 SS

What RPM did you make your Peak HP/TQ? I must have some problems I don't know about yet. I'm going to try a leakdown test and check my valve springs. I was able to adjust in enough fuel to keep the A/F around 12.5 all the way up to 6400 and We played with the timing and it didn't show any gains past 33 degrees the engine never showed a hint of knock so I definitly have more issues than just my fuel pump. The boost kept rising with rpm to about 14#s at 6400. Any Ideas?

Thanks
Jeff
96 SS Blown
96 TA 396 D1

IDOXLR8

My max power was made a 6000 rpm.

Highlander

Either the tires where spinning on the dyno or there was valve float, very common with weak springs and the XE cams.. I think I had valve float since I did 555@5750 and max peak that was 517@5500 on a mustang dyno, Tires where up in smoke though... but I think I was having some valve float also.. so I am revving it till 6200-6300 not more than that...