Hey guys. Heres my deal. I installed a heads and cam package from Advanced Induction (180cc package) on my car along with a rebuilt and bored bottom end. To be honest, to some degree the car feels weak for the amount of work done to it. I've narrowed it down to a few things that might not be helping me, but I really need some good advice on where to take it from here.

1.)Tuning. I bought LT1 Edit, kinda tuned it. Shifts hit off the rev limiter because it's setup wrong. Am going to pay Brian to send me a .LT1 file to correct my mistakes. Also plan to have it dyno tuned.

2.) Exhaust. Catback is fine, but I'm running MAC's with a high flow cat. Is this REALLY that bad? I thought the mid-lengths would be okay for it.

3.) Injectors. Right now I'm running the stock injectors due to not having a proper tune. Will these help at all when I have them in and tuned corectly?

4.) Gears. Stock 3:23's. I have a feeling that this is a major setback.

5.) Intake. Intake isn't ported, stock throttle body. Probably not doing me any good either.

So there it is, let me know how bad this is.

 

I have limited experience so far but heres my 2 cents...

1 A dyno tune would greatly help get the most out of the mods you have done

2 MAC headers arn't THAT bad they are long tube headers right? If you have emission laws then keep the cats.

3 I don't know how much the stock 24lb injectors can handle but I know people with over 300RWHP on stock injectors.

4 If you want more acceleration you should swap 3.73 otherwise your ok

5 Many people say the stock throttle body can handle a lot of power and an unported MAF is better because a ported one would make the engine run lean.

 

Yea tune mostly, probably close on the injectors eventhough 28lb are good for almost 450rwhp i would think 24 are good for around 380rwhp?? TB and Maf dont waste your money i know someone with a 383 that made 504rwhp with a stock tb and maf. swaped in a 58mm tb and made like 507rwhp so save that money for if it isnt tuned start with that. good luck.

 

Define "feels weak". Do you have dyno results, or track results? If so, what are they? If not, how did you decide its "weak". Did you contact AI to see how well your setup complements their "180cc" package? They are the ones that say it will make anywhere from 445-475 flywheel HP.

Without knowing your specific tuning skills, its impossible to know how much you limited the performance, but seeing the words "kinda tuned it" and "set up wrong" would seem to indicate there's room for improvement.

What catback? The MAC's aren't great, but they're not "bad". Is there a cat included in the system, and is it a high flow replacement?

The stock injector program value is 24.9 #/HR. Assuming you had a good tune (0.46 #/HR/HP) and were willing to push them to 90%, they are good for 390 flywheelHP. Push them to 100% DC (not a good idea) and they can hit 435 flywheel HP. Run them on a weak tune (0.50 BSFC) and they are going to roll over and die at 400 flywheel HP. Why would you run a stock injector on an engine that has the potential for 445-475 flywheel HP?

With what stall? Might cost you a bit on the bottom end, but shouldn't produce a "weak" feel once it gets rolling.

What does AI recommend to support their heads? Appears they are keeping the volume of the heads (180cc) very close to stock, so there shouldn't be a huge mismatch on the ports with a stock intake. There's very little to be gained by "porting" the short runners on the LT1 intake. A 48mm TB probably starts to act like a cork around 400-425 flywheelHP

Yes.... several of the things you have listed are "restricting" your engine, but I'd think it would be a good idea to quantify the problem with a dyno pull or a pass at the track, rather than relying on SOTP. You've already proven it doesn't make any sense to cut corners.... like using the stock injectors, etc.

 

As in terms of feeling weak, it just does not seem like the power is there. Maybe it's just me and I'm expecting more from all the work that is done, and really there isn't as much as I thought?


I have no tuning skills. Period. I understand some very basic stuff, but I am no Brian, Alvin, Jeff Creech, Ed Wright, or Ion.


Catback is a Borla. There is a cat in the system I'm running. It is a Magnaflow high flow cat.

The reason was because of the tune. At the time, the tune was stock, and I did not want all of the fuel the Ford #30's washing out the cylender walls on my new heads and thus destroying my new $3,000.00 investment.

Yanks SS3200. I was hoping it would pull strong up top and it just dosen't seem like it's there. Thats why I fugured gears would help.

I do remember Ron telling me that I wouldn't really benefit much from having the intake ported. So do you suggest porting the stock TB to 52mm's or go all the way up with an aftermarket 58mm?

I didn't really spare much expense with this whole deal. It was do it right or don't do it at all. I know it definatly needs a dyno pull. I was going to run it down the track last Friday but the track ended up being closed. Thank you for your detailed response Fred. Let me know what you think.

 

Chances are your tune is pretty far off. You need to get the car on a dyno with a good tuner to get the car dialed in.

You are leaving some power on the table with the Mac headers instead of running a LT header. I'd guess in the neighborhood of 10-15 rwhp across the board.

As Fred stated, the stock injectors are not a good idea. You said the car doesn't pull hard up top - you are running out of fuel.

3.23s cartainly aren't helping, but I'd start with the other issues first. You'll want to step up to a 3.42/3.73 and a decent size stall. AI should be able to recommend a converter for your setup.

There is some power to be found above 6k with a ported intake, but again, you have other prominent issues to deal with first. Also, I'd run at least a 52mm TB if not a 58.