The goal I'm shooting for with my LB9 is 400HP N/A at the motor. So far no matter what I try I can't squeeze out more than 357HP.

Here is a quick breakdown of the mods:

52mm Throttle Body
Ported Plenum
SLP Runners
Accel Base
Accel 30# injectors
AFR Bare Castings ported to flow 298cfm @ .550" lift
Custom grind cam, 223/232 - 509/530 - 114.4
SLP Tri-Y Headers w/High Flow cat
SLP 3" 2 On the Left Catback
DIY PROM

and a ton of other small items like roller rockers, etc.

Based on what I can find here for the valve relief volume on stock LB9 pistons (-12cc) and with a 56cc chamber on my AFR's along with all the other needed numbers, I figure a 9.16CR with a 0.041 gasket. Which is fine because I'm adding a ProCharger to all this in the end.

Is there anything you guys can suggest that might give me the numbers I'm looking for? These are all Dyno2003 figures because the heads won't be on my car with my cam until December.

Things like a higher CR and different cfm flow on the heads only seems to make a small difference in HP, like 0-5HP so I won't find it there. I'm not going any wilder on the cam because I need to stay CA legal, plus I just got it a few weeks ago. I'm hoping that in the real world things like the roller rockers, plenum porting, intake port matching, and all of the other details will add up to atleast another 30HP that Dyno2003 can't predict. The new forged bottom end I plan for next year will have pistons with the same volume but with a 0.078 gasket or so to lower CR just right for max boost. It will be balanced so over stock that should be good for a couple HP plus it will be lighter.

Any ideas, comments, etc?

 

My motor should make 409hp at 6000RPM (and maintain 400HP to 7000RPM) and 377tq at 5000RPM according to DD when I'm all done with it. I don't think it will be that high but I'm hoping to be somewhat close to where you are (I won't have as much torque though).

How is that cam, and how was tuning it? I have a cam very similar that I'm having second thoughts about installing. 222/232, .479/.501, LSA 114.0

ported LT1 intake, ported LT1 heads with about 9.8:1 CR (guesstimate) and 2.00/1.55 valves, Hedman 1 5/8" headers, 24# injectors, 1.6 roller rockers, EX-612 valvesprings, etc.

I haven't done any of this yet, I'm saving up for the headers, and valvetrain stuff.

EDIT: Just realized two things...you are using 2003 version, I'm using 2000 version, and you haven't installed your cam yet..

 

Put a Miniram or ported LT1 intake on it and you should find your missing horsepower. What is the bottom end like? A proper internally balanced assembly with forged pistons and so on could add hp.

 

I don't see how I'm going to lose horsepower by adding a Miniram or ported LT1 intake. I'll gain a ton of top-end. I'm going to lose torque on the low-end though, but I already know that. That's what the higher rear gear and higher-stall torque converter will be for

I don't see how forged pistons add any horsepower at all unless they are higher-compression pistons, but you could do the same with cast pistons (not that I would ever buy cast pistons).

Anyways my plan is to get as much out of the 305 as possible and then swap it all over to a 350 in the end.

92GTA You should have one powerful engine. I wish you had that cam and heads on already so I knew how it'd run!

 

First off, I'm not going to change my intake. I need to stay CA legal which means EGR. LT1 intake, I don't like having all the ugly cooling lines everywhere with a remote thermostat and the Miniram does not have EGR. So I'm stuck with a modded TPI intake which is what I have as listed above.

I already covered the fact that I would have a forged and balanced bottom end next year which your right, will yield some HP as I mentioned in my original post.

I plan on sticking with the 305. When I install my new bottom end next year, I'll splay the main caps because once I increase boost with the new forged internals, I'll be seeing atleast 650HP, probably 700HP but at that point my tranny and rear would be the weak link so I'll have to keep it around 650HP at the wheels.

Anyway I went a little off topic. Any other ideas for me or do I just hope that the real world gives me a dyno of 325RWHP or that my new balanced bottom end takes care of the rest...

 

What??

Where did I say you would lose hp?? I said you would find your missing hp, missing as in the hp you are looking for.

And a balanced and forged bottom end does add hp. It can rev smoother and faster, and it is lighter, therefore hp goes up.

 

Ah okay, makes sense. Thought you were saying something else, sorry

 

What about a torque conveter? I've seen dyno's of people installing a good Yank 9" and gaining 50ft/lbs at the wheels! I was going to upgrade from my 12" 2400RPM stall to a Vigilante 9" 2800RPM converter, do you think that would give me the difference I'm looking for?

 

With the kind of power you already have I wouldn't waste time with anything less than a 3000. I have a TCI 3000 and love it.

 

Kewl!

 

My plans include some sort of a 9.5" lock-up 3000-3200 stall torque converter and some gears larger than my 2.73s. The gears will probably be the last thing to get done though out of all the stuff.

 

I'd be genuinely surprised if that engine even makes the 357hp. I just don't know if it's possible. That's also an assload of cam for a TPI 305, AFAIC. What size valves are you planning on using? It would be awesome to pull that power out of a 305 though so i hope you pull it off.

 

yah i am no expert here but i am really questioning these power numbers. i dont think an N/A TPI 305 is good for much more than about 330 horse, mainly becasue the cam and heads required to make more power will way outflow any long runner setup. i realize you are tryin to stay Calif. legal, but i just dont think more than 330 hp is possible with a LTR setup. i encourage people to prove me wrong, an LTR LB9 with 400 horse would win enough money on the street to build an LS1.

 

Well I'm going to push it as far as I can so atleast if anything, everyone will know without question what an emissions legal LB9 can make with top notch parts and tuning.

Speaking of tuning, I just finally finalized my cars chip today. In a few weeks I'll be installing a WB sensor and checking it again. Then I'm going to chassis dyno it to see exactly what it makes right now. Then I'll dyno it again when I put the new heads and camshaft in and re-tune it. After that the blower will be going on and I'll re-tune and dyno again. Next year I'll be redoing my bottom end and dynoing yet again N/A after re-tuning but it will have a much lower C.R. then to run max boost from the ProCharger so if anything the dyno numbers may be the exact same although once I re-install the ProCharger and run max boost it's will be ***** to the wall:rockon:

 

Why someone would make a generlazation like that I will never Understand. To get the correct Stall it depends on a lot of factors, a converter that is ordered for a specify combo will have a different stall speed it it is on a different combo. Just call Vigilante and they will walk you through it, and they offer one free stall adjustment. If you need a converter that was designed from the ground up to Run in a High Horsepower application not a Factory convetor that was Modified to change stall go with YANK, PERCISION INDUSTIRES (Vigilanti) COAN, And just for your info I have had two cheap low buck COnvertors : B&M and a TCI neither one lasted for more than a year under racing Schedule, and FYI when a generic convertor Lets go It take Most of the Transmission with it.

Just my Experiance and .02

 

My cam would dictate a 2800-3000 stall considering the rest of my mods so it was a good guess. My peak TQ will be at 4000 so I'll more than likely get the 3000. I was either going Yank or Vig., still don't know. I'll call when it's time and also tell them about the SC'er I'll be installing...

 

I made that general comment because I speak with experience. When you start adding power, you "generally" move your powerband up, and a higher stall takes advantage obviously. Adding alot of power and only moving your stall up a few hundred rpm's is useless.

As for cheap converter's, I don't consider over $800 canadian for my coverter cheap! And my TCI has held up for two years now with no problems.

 

try porting the runners and plenum and base as much as possible, and gear the car according to your hp peak, probably no higher than a 3.23 gear and a 2800 stall.

a superram is legal in cali, and would get you some more rpm and power in the midrange and up top.

 

i dont know i ran a tci convertor in my 700r4 for almost two years taking the car to street stock almost everyweek and had no issues. down here in houston there is a place called brittains that custom makes great convertors and is very reasonable, i have ran his convertors in my th-350 and in my wifey's 4l60 and they have been great usually cost around 250$ -300$. i think he use to make all the convertors for gravedigger. anyway, the vigilante i had was a pile and the yank that i tried came apart on me so i sold it to another sap after i got it fixed ,so i think different people have different experiences. the fact of the mater is that you need to match your convertor to the power band of whatever cam and head and intake you have. you also need to make definetely sur that the c/h/i all are matched for each other or you will have some serious power band "dead" spots.