Dannysz28

Ok I have a 95z a4 and with hpp3, 4.10 gears, underdrive pulley, and cai it ran 8.50 in the 1/8.
Now i stroked it to 383, has 10.5 to 1 srp pistons, h-beam rods, pocket ported heads, cc306 cam, 1.6 roller rockers, tune by pcmforless, 28lb injectors, bbk shorty headers, corsa catback, electric water pump and it just runs like ****!!! Its not missing or backfiring, it just dont seem like it has much power. I tried it at the track and it only runs 8.65 in the 1/8 now. Has good fuel pressure. Plugs are kinda white on top and around the electrode but are really black around the first few threads closest to the electrode. It has a stock fuel pump. It seems like it is burning a hell of a lot of gas and its not leaking gas anywhere.

brain

Shorty headers don't help. Curious, did you degree the cam? I know I'm beating a dead horse, but there are SO many people that mod these cars and have a similar problem, it has to be somewhere. When you say pocket ported heads, what do you mean? Have they been flow tested? I would expect at LEAST 350 RWHP from that combo. What mph does it run? My car went 8.0 on motor, and 8.0 on a 130 shot, granted it went from 88 to 91 mph, and it was spinning, so e.t. isn't definitive. Do you have a stall? You didn't list it, if so. That will help you a good bit on e.t. as well. If you get too tired of it, you can give me the 383 bottom end, and I will put a nice set of heads on it...

LT1Squirrel

what did you put down on the dyno?...how did the A/F look?

ShawnMacAnanny

Maybe your rockers arent adjusted right. I just adjusted my stock ones last night and my car seems to be running a little better. Take out your HPP3. you could be screwing up your tune with that. It does sound like mis adjusted rockers. Sounds like they are too tight and your arent getting full compression. Also check that your spark plugs are tight. 5 of mine came loose after the header install and caused me to lose power.

WS Sick

Define pocket ported heads, if you slapped a set of 3 angle valvejob and blended heads on a 383 then you put a sock in it right there. Have you had it data logged and then retuned? They never run right the first time .

If youre displeased with the 383 parts you can send them to me and I'll give them a hapy home.

Dannysz28

How and where would i get it data logged at? I dont have the a/f ratio but the plugs a kinda white looking so i guess its a little lean. Also it has started popping back through the intake and backfiring when you let off. When you just barely lay your foot on the gas the rpms drop for a second and it tries to pop back or if you hit the gas from an idle it will also pop back pretty hard. Im not sure but it seems like to me even if there was not any work on the heads it shouldnt slow down should it? I have a bone stock 95 TA that will run just as good, if not better than it will. I will be putting 36lb injectors in it wednesday or thursday because i was told the 28lb ls1 injectors were not enough.

Dannysz28

Also it has new plugs(tr-6), wires, coil, and module. I checked the air intake for rips but there was not any.

gogogadget

It needs tuning. A backfire out the intake is usually a lean misfire.

Why only 10.5:1?

AF96Z28

I feel for you. I'm going through the same thing. I don't know if you said it before, but what were your 60 ft times? I have the same tune you do, but I seem to bog down off the line. I'm gonna dynotune before I really start tearing into things.

NOMAD

Are you running a Cloyes true roller or another brand roller chain besides the stock one ?

You also cannot base anything on track times. My car ran 15.6's at the beginning of the season last year. My MPH was over 109. Total loss of traction after all the engine work.

-Shannon

jay_lt4

ls1 injectors are only 28#/hr if the fuel pressure is raised to 55#, if you kept the fuel presure stock then they only flow 24#/hr same as the stock injectors, so if you put the ls1 injectors in and changed your pcm tune to 28# and you are running #43 psi your engine will be running very lean

SPEED750

I had my rockers to tight once and it backfired thru the intake. I think your real problem is the heads. Stock heads with a pocket port isn't gonna flow enough for a 383 to make big power. Youv'e got a big cam and big cubes, you need big flow numbers.

Dannysz28

I had pcmforless to tune it for the 28lb injectors but i have some 36lbs that are coming this week. As for the stall, it has a 2800 in it already. Im going to check the valves when i put the injectors in and make sure they are right. I know the heads are holding me back alot, but i didnt figure it would slow it down considering all the other mods that were added with the 383. I hope it is popping back because it is to lean. When i put the 36lb in it, what fuel pressure do you all recommend? How do you check the timing on these cars and make adjustments?

Dannysz28

I went with the cloyles double roller timing chain. I was thinking the timing might be one tooth off, but i hope not. When i went with the 383, I also added an electric water pump, headers, corsa catback,1.6 rockers, 306 cam. I really thought it would pick up at least a few tenths and not slow down.

got_hp?

something (maybe more than one thing) is definetly not right.

even with bone stock heads, a 306 cammed car with your supporting mods should be around 340ish rwhp.

start a list of the things everyone is suggesting and start checking them

adjust rockers correctly
have someone datalog a run (check for knock retard)
find out your A/F ratio
get proper tuning (mail order tunes suck)
make sure you degreed cam
im sure theres plenty more to check.


definetly make sure you got a proper dyno tune in the future, it will run so much better.
let me tell ya, im am NOT a fan of mail order tuning...... even after giving the tuner my full parts list and cam numbers/head numbers, the mail order tune i recieved does not idle correctly, runs way rich, and surges like a ****. im only using it so that i can break it in, and drive it up to the dyno to get proper tuning.