crazyd

Engine stats: ZZ430 (ZZ4 shortblock, ZZ5 fastburn heads, hot cam kit)
FI stats: S&P Ram Port, custom manifold with TPI components.

This does NOT live in an F or Y-body. It's in a P.

This engine is rated at 430hp with a 750CFM carb.

I had it set up as a ZZ5 385hp fastburn and ran it on the dyno. 273 at the wheels.

Set it up as a ZZ430 with the hot cam kit, it did 276 to the wheels.

The dyno graph shows the torque is flat to 4500, and then it starts a prematurely steady decline. So it could be a lack of air, fuel, or spark.

Air: 48MM TB.
Fuel: 25# LS1 injectors w/LT4 regulator, 14" vacuum from cam. FP is usually 38-40 PSI.
Spark: Stock distributor/coil units, external coil, 8mm plug wires to AC MR43LTS plugs (yes, stainless-steel marine plugs) set to .045. Base timing is at 10 deg.

Chip programming for the 262 ECM is by S&P for this setup. All components are as provided by them in the Ram Port kit.

Exhaust is true dual 2" with Sanderson CC90 straight-dump headers to twin cats and twin bullet mufflers.

What's choking this thing off?

Thanks,
Dave

Jim85IROC

iTrader: (2)

TPI couldn't even feed a stock 350 over 4800 rpm. Forget about it feeding a zz430. Since you've got fastburns, (and I'm assuming you've already got the SDPC vortec TPI base), I'd say you'll need at least a super ram, or better yet, a mini ram, which they make for vortec heads now.

I realize that the fastburns have the bolt holes for conventional intakes, but since the runner design is different, you should still be using a vortec-specific intake.

crazyd

Okay perhaps I didn't make it clear. This uses an S&P Ram-Port manifold, NOT a TPI manifold.


Click here for a picture of the engine.

kevinc

You may have missed the "S&P Ram Port" intake he listed in his post. No TPI plenum/base/runners there, just the electronics.

I agree the dyno numbers are low, my 355 with GM aluminum L98 heads and HOT cam made 287hp and ~350tq (SAE) to the wheels last year.

Your injectors and software may be suspect. The LS1 injectors' flow rate is calculated at 58psi, if your lower delivery pressure isn't accounted for in the software injector flow rate constant you'll be under-delivering gas and running the engine lean.

If your dyno guy has a wide-band O2 sensor, use it next time and see what air:fuel ratio you're feeding the engine at WOT. Very useful tuning data.

You'd also want to get a laptop and ALDL cable so you can acquire data on spark knock. The generic S&P chip may or may not be close to your setup, getting engine run data is the only way to be sure.

Jim85IROC

iTrader: (2)

Yup, I missed that completely. Sorry.

Joshua

Dual 2 inch is kind of small if you're going past 5000 RPM.

crazyd

Peak power is at 6400rpm on this setup, and I've got the limiter set to 6500 so it's really gotta breathe. I intended this to be a revver, not a torquer, and it fulfills that role nicely - it's just not making the power up high that it should. I think 400hp is reasonable to expect with the only accessory drain being the alternator and water pump. Can a 48mm TB move enough air for that?

Due to space constraints it was impractical to go to a larger diameter exhaust than the 2". But the pipes are only about 4 feet long so the exhaust doesn't have far to go. I've long since outgrown loud cars and am willing to sacrifice 10 or 15hp for it to be quiet.

1bad91Z

iTrader: (1)

That link doesn't work, so I was unable to view the motor. Also, you need to switch to NGK-TR55 plugs for your fast-burn heads. ECM could probably use ALOT of tuning. MSD ignition 6a box with Blaster GM coil would help out to. LS-1 injectors are bigger than 25 lbs. They are like 28 lbs. I think. How rich is the motor running and where is your base timing set?

If you answer all of these, I could help you from there.


Mike (1bad91Z)

crazyd

Mike - I posted a new link above, try refreshing the page. I've double-checked the link and it should work. If it doesn't, try this one.

The blurb sheet on the Ram Port kit says the injectors included with it are "24.9# LS1 injectors". Maybe LS6's are 28#?

I have heard good things about the NGK plugs but I want to get the thing to where it should be before I start trying to take it past there, unless that is part of my problem. I'm pretty sure those are the GM-spec plugs for the engine, at least with a carb.

I'm still uncertain about the existing plug gap since this is a non-HEI distributor/coil setup, if anyone knows what it should be I'd appreciate it.

The plugs at this point indicate that the engine is running quite rich, but there is an air filter problem and an exhaust problem that need to be cured first before I can get a solid report on what the A/F mix looks like.

1bad91Z

iTrader: (1)

First, try changing to NGK-TR55 plugs. The change your injector constant setting in the PROM to 25 #'s. Then see if it runs better. You really need a scanner to monitor BLM's and such to see where you need to go from there.

Oh, and the links didnt work again. Just post the pic here in this topic.

crazyd

Here's the picture. I hope it works this time.

bigals87z28

i would go with a bigger tb if your going to match taht 430hp. a 58 would do you good right now. larger exhaust, and thoes headers look restrictive, but that could be me. I dont know much about that intake as i have never seen anything like that, Advance timing to 12*-14* and go with a better plug. Also, do you have some type of CD box like a MSD, Mallory, etc.. something that will increase spark? Thoes are very little numbers for a a 430hp block. Im surprised your running rich.... 24's would sound like they are very little for that big of a block. thats just my .02.

1bad91Z

iTrader: (1)

Looks good, you would most definitely benefit from long tube headers! Try those NGK-TR55's and see what you think.

22 lb. injectors can flow enough fuel to make upto 450 HP.

I have 24 lb. SVO's on my motor and they have made my motor run eye watering rich until I tuned it!

AaronIROCZ

iTrader: (5)

Is that a fwd drive car you are bolting it up to?? To me looks like it is sitting in the cradle and looks like a fwd trans axle mounted to the back of the motor. If this is correct then I don't think that long tubes will work.

Slow89Iroc-Z

total insanity... P body!!!

crazyd

crazyd

It's not a FWD car, but it is a FWD transaxle. The car is actually transverse mid-engined. No, long tubes won't work. Headers are too much trouble for me anyway. They run hot, they come loose, and I don't like how they sound.

Dave

crazyd

I did some research today and it looks like a 48mm TB will only do 635cfm, whereas a 52mm will do 750cfm. Is that correct? The engine is rated with a 750cfm carb, so it looks like I've found my problem. 58mm would probably be overkill and might give me drivability problems. Now I will have to find out which TB is used in the kit so I can upgrade it. Any recommendations for upgrades? Are the bored ones I see on eBay any good?

Thanks,
Dave

DannyT

The general consensus is that a 58mm TB is recommended for motors with 400+ HP. I wouldn't say they are absolutely needed over a 52mm TB though.

bigals87z28

I would go with a new one as they are really pretty cheap. I have seen ones that some company made, and they were like 300... thats a lot for a tb, but most are way over 300. Also, i dont know what that intake flows, but it doesnt look like anything i have ever seen.. i dunno, most cars putting out that much power ususaly go up to a 26#-28#... but i guess you could work with a 24#.

crazyd

This is the setup. Does anybody recognize that TB to know where it came from?

S&P Ram-Port Injection for Fast-Burn Heads

kevinc

I'm running an Edelbrock/BBK 52mm and happy w/ it. 13.19sec @ 102mph back when I had an auto trans, 13.5sec @ 105mph with the T56, with a 355, HOT cam, and TPI + Accel base pushing it.