Car is a 98 z28 with a mildly built 382 stroker with 3.73s. it cruises and idles wonderfully but its slower than a 14 v6 camaro and idk whats going on and need some help!

Build:
LS1 Block
Summit Pro LS rotating assembly 10.5:1 CR
244/250 .612/.613 112lsa
#42 gtp injectors
320lph fuel pump
LS1 intake
PRC 2.5 5.3 heads milled to 58cc
Mail order tune
I thought maybe it'd be the ls1 intake but surely it wouldn't restrict it that much would it?

 

Mail order tune only?
If so that's a big part of it

 

cam duration and compression just don't line up to well in my opinion for your cubic inch motor.

 

It was a specd cam from a 408 but the options I had at the time was a 224r or that one for 50 bucks. Maybe its time to just get one specd for my needs

 

sadly yes everyone around here wants to charge out the rear for a dyno due to it still having the 98 ECM. Which will be changed out here soon

 

You're missing a point of compression, that cam is a poor choice, and you're running a stock intake choking the crap out of the motor.

 

Agreed. And add to this the tune is basically a startup tune.

 

I figured as much. Just bought the heads and cam for 600 bucks with very little use and they came off a similar set up so I figured it wouldn't matter to much. Guess that's what I get for not doing research and/or talking to a professional:/

 

Mail order tune? Those should be used for startup and cruising.

Cam is sized wrong but should still make great power if tuned correctly. A fast 102 intake would get you 30 HP on that setup easily.

 

~ Get rid of the intake ASAP. You need a fast 90 or better.
~ Get a real Tune.
~ Get a 23X duration cam
~ bump the compression ratio up

You never mention was the car automatic or 6 speed. If the car is a 6 speed you go need 4.1X gears minimum and if you are automatic then s 3000 stall isn't going to cut it eithier. Several things to look at here....

 

Yeah sadly has the 4l60e with an fti 3800 stall. With the way things are now a days moneys tight so I'm having to work with what I have just trying to get pointed in the right direction.

Intake and tune are on my top priority list. Yes I need a better cam but it should work just fine for the time being. Nothing serious just a fun street car.

 

 

16cc dish, I had plans to boost it later on and wanted something in the 10:1 range.

No, I don't. When purchasing the fuel pump I had no idea what all to get as this is my first real build (something other than just cam and exhaust) but after reading more and asking questions a hot wire kit and a few more things are on my list to get asap.

Yeah most dyno sessions around here are $600 but its like every place I talk to want $950 after I mention the 98 ECM. Although I have talked to some smaller tuning shops that would do it for 400 but I don't know of I can trust them enough.

 

I just had my LS1 tuned for $440 here in Australia he spend close to 4 hrs on it dynod and road tuned it, but some cams are hard to tune, I'd recommend using a cam that's known to be easy to tune as that's where the costs can go up. But if yours is already running well it might not cost much to tune. You will need good heads to get the most out of that cam, or just go for much milder cam and go for big torque and dont worry about peak numbers, then the heads won't matter nearly as much.

 

maybe I missed it but what did the car actually run?

 

I agree some things on the car are not optimal but it still should run pretty well with that much motor and a 3800 stall. I had bolt ons only with a 3800 stall and would kill a v6 camaro.

The tune would be a major concern, and also making sure the basics are good (tune up, fuel filter, fuel pressure etc) and if all those things are good the cam could be off timing, or the tune is just so bad it's not working out. You really need some info to help sort this out though like the timing, air fuel ratio at wide open, be nice to know what it's actually putting down to the tires too.

In other words you could get by with that setup if need be due to budget, we've all been there. And if you really want it to be the best it can be then yeah I'd look at a different cam and intake, but I get the feeling something else is going on here.

 

I'm not going to read the replys so If this has been covered sorry lol

The whole combo is a mess . Not being rude just honest.

Low compression. -15cc dish? Good lord lol
Massive cam
Horrible intake
Email tune on a 98 ecu
What headers/exhaust?
Guarantee a tune will gain over 100 hp by itself.

Ditch that cam, ditch the intake, swap out the pistons if you want to make good all motor power. The heads you have seem to be the best part of the build

 

Whoops my mistake re the heads, I was thinking they were stock.

 

9.5 1/8th but it kept breaking up (had a vacuum leak and dint notice till i got home) but my old c10 with a cammed 5.3 and exhaust went 8.6

 

Nah totally understand lol and the cam was cheap why i went with it. I had plans to boost it which is why comp is so low but I didn't figure itd be this slow. I did get help on the tune and it opened it up a good bit but still need to make the necessary changes. Intake being first then tune not worried about cam as itll be changed once it gets the big upgrades (turbos. Holley (which I know how to tune) ect.)