I ran at the track last night twice for the first time since the engine rebuild and posted a 13.6@104 and a 13.8@104 both without NOS. There has to be something wrong with the tune because I was expecting to run at least low 12's high 11's. The motor is a 383 with the following: Eagle forged 4340 crank Scat 6.0 forged rods Wiseco Pro-Tru flat tops 11.5:1 CompCams 12-432-8 xr282hr 10 cam .540 int .570 exh with 1.6 ratio roller rockers Edelbrock High-Flo TPI base intake(non-ported) Accel Super Ram intake FMS 30lb injectors AFPR set at 50psi AFR 195cc Eliminator Heads 65cc SLP 1 3/4" headers This combo dynoed at 382rwhp and 425rwtq with a rich tune. I ran a leaner tune and more timing at the track but the numbers just don't match with the dyno numbers. I should be seeing 11's or low 12's. Maybe this motor likes a rich tune? What do you guys think?

What were all your times through the quarter? traps, 1/8, 1000ft., etc? Do you have the sheet still? Could be a wheel spin, grip issue...maybe not launching like you need to be...rear gearing, auto or manual...not sure. If the set-up is right I would think 12's as well.

1st run:

60' - 1.9sec
330 - 5.8sec
1/8 - 8.9 sec @ 82.59mph
1000 - 11.5sec
1/4 - 13.681sec @ 104.03

2nd run:

60' - 2.533sec(wheel spin)
330 - 6.2sec
1/8 - 9.2sec @83.75mph
1000 - 11.728
1/4 - 13.871sec @104.39

My second run was supposed to be on the bottle but when I looked at the timeslip I thought to myself no friggin' way and then I looked down and saw that I forgot to arm the switch

Something wrong there.
Even allowing for the weight difference my Vette went 12.7 109mph 1st time out on a bad tune.
Similar spec engine ,393 11:1 ,224 / 540 cam ,TFS 195's , SLP's and home ported base / plenum.
A4 , 3.07 W/ 2K stall.

you're peak numbers look great but hows the power under the curve? I'm sure its decent considering your peak numbers but yeah i'd have expected a mid 12 pass considering your 60ft. What kind of rubber you running btw?

Tires are street tires Bridgestone Potenzas to save the rear and tranny. I richened the tune today and made a couple of WOT passes on a secluded road somewhere in Mexico and I can feel the difference it made. This motor loves fuel and lots of it. I'll be going back to the track next week and see what it does.

I wonder if my motor needs to exhale more. I have a single 3" catback exhaust with cat delete. I think that might be restricting the engine.

yeah you gotta be nice to the stocker so i feel ya on that. lol Good luck on getting it figured out man.

You might need to go to the 4" single exhaust if you don't want to run duals, but I thought the 3" could handle up to 400hp...but if that's motor hp and not whp, you may be beyond that threshold already. I don't know about a full second though of restriction... I am leaning toward launch/gearing maybe. What rear gear do you have? The street tires aren't helping either...some M/T drags might help...just doesn't seem right. Even running where you are with what you have in the descriptions it should be faster I would think.

I'm running 3.73 gears. I'll have to research to see who sells the 4" exhaust. I'd like to run true duals side-by-side using the shorty headers. Someone else has done it on here but I don't remember who it was. The dyno numbers are rwhp.

If you are running shorties, that may be a part of it too...long tubes are the way to go for aftermarket headers...shorties are a step up from stock, but just. The 3.73s are probably good...I was thinking maybe it was there. My guess is still in suspension/tires. Do you have any upgraded suspension yet for the new power? Sway bars, rear LCAs, Panhard, sub frame connectors, etc.? You'd be amazed how much the little bits of grip here and there add up in the big picture. Plus they are stronger and lighter...weight reduction is always better, especially when you are getting a stronger part too :-D

Here is my suspension work:

Front
Polyurethane bushings on A-arms and swaybars and KYB shocks
Wonderbar

Rear
LCA relocation brackets
UMI lower adjustable LCA
UMI Adjustable torque arm and tranny crossmember kit with d/s loop
UMI adjustable panhard bar

I get absolutely no wheel hop. I also have Chris Alston subframe connectors.

Yea, you should be good there. I don't know what it is. You're at sea level here in Florida, you've got the suspension, the motor, gears. I'm not really sure. It has been very hot...the heat kills times as well...again I don't know about how much, but it does hurt. We're coming in on fall and cooler PM temps for night runs...see if they come down in the cooler nights. I don't know...seems pretty spot on. Tuning maybe...might need more tweeking is all. Keeping it the power band as long as possible is key. My shift points being off hurt me pretty bad my first run...adjusted and got a couple tenths...it was an auto though and had to be manually "slapped" through the gears as the mail order chip burn didn't like shifting right in drive alone.

You're probably right. I'm using an LM1 wideband to tune and have been trying to keep wot a/f ratio at around 13:1 but the the car seems to run stronger in the 12.2:1 range.

i dont know how much exhaust is hurting if at all, or what tune that motor really wants on the street, but......

Whatever tune/exhaust/motor setup you ran on the dyno to make 382whp, run that setup at the track and see what happens. THose numbers, regardless of how the power looks under the curve, will EASILY do bottom 12's on street tires. With 1.6-1.7 60 foot on good tires, your mid high 11's at 116 mph. You make as much power as my 383 did and i was in the 11.6's at 116 first time out with a crap street tune. dyno tuned up it ran 11.4's at 118-119.

Run it richer on the dyno if its not a load bearing type dyno which most are not. Street will put more load on the motor and hence require more fuel. Give it what it wants. Richer dyno tune will lean out on the street due to more load from real time conditions

Even without knowing the exact weight of your car, if you only ran 104 mph you definitely were not making 382rwhp during that run. Probably more like 300rwhp or less. Thats a lot to make up for in the tune. Numbers just don't seem to add up.

I agree 104 mph is not a 382hp car. If it were a traction issue you may have a bad time but your mph would be probably around 115mph if it were truly a 382hp setup. If it really likes fuel you may need to up your injectors you may be maxing those 30# injectors out.

Be careful with that nitrous and those 30# injectors. You are running a wet kit I hope.

I installed that chip and will be heading back this week hopefully. I wonder if my w/b is giving me false readings? When I went on the dyno they made 3 passes - 1st pass made 375rwhp and 415rwtq, 2nd pass 365rwhp 405rwtq, 3rd pass 382rwhp 425rwtq. Even with the lowest number I should be in the 12's easily. Major head scratcher here.

P.S. It's not the driver

what EFi system do You uese, can You show any VE and SparkAdvance tables, if you use MegaSquittII tnah Your msq file would help alot

best regards

I'm not sure what the issue is but I tend to agree with the number not matching up. My motor is dyno'ed at 390hp and 426ft/lbs at the flywheel. This equates to a 110mph pass in the 1/4. Mind you these are flywheel numbers and they're almost the same as your rwhp numbers. My 390hp at the flywheel should be around 305hp at the wheels through my 700R4. If that gives me a 110 mph pass then you should be quite a bit faster than that.

With a 104 trap mph your not making the 380 whp plain and simple. Something changed or happened from the time you did the dyno to the time you ran at the track. Might be something simple like burned spark plug wire or throttle cable slipped i don't know. But it's missing some power now.

EST wire connected? I did that once... forgot to connect it again after checking timing. I ran a bunch slower on my bolt on L98. I was 4-5mph down and half second just about. On a bigger motor you may see more of a difference

But i'd definately suggest putting in the original 380whp tune and seeing how it goes. Verify your wideband is working correct and do a street pull through the rpm range to see what your air fuel is. If your anywhere near 12.5-13.0 to 1 and your running 34 degrees of timing or so, you will have a 11 second car.

I will post what my ve and spark tables look like shortly since the bin files are in my other computer. Est wire was connected. It's really pulling alot harder with the dyno chip back in place. I had pulled the plugs before putting the dyno chip back in and there is evidence of slight detonation with very few black specks on the porcelain. #1 plugs looks slightly glazed. I think I need to recalibrate my w/b because I believe it's giving me false readings. A/F ratio during the runs were between 12.5 and 12.9. Now with the dyno chip back in I'm reading 11.9 to 12.2.

Ok here are a couple of screenshots. The first one is from the ve, spark, pe spark adv, and pe % afr change from the the dyno chip. The 2nd screenshot (yellow tables)is from the chip I ran at the track with. I zeroed out PE spark and adjusted total spark via the main table. I also changed pe % afr in the upper range.

You took out alittle fuel from PE mode from 5600 rpm on up where it will need it the most. Not sure if 8-10 percent more is all that much more change with speed density, as on my MAF car 10% change wasnt much difference, but obviously that motor wanted more fuel from 5600 on up.

You richened up the meat of the torque curve (4000-4800) a good bit too..perhaps too rich? It may have liked the other PE values.

May beable to try another degree or two of timing for 34-35 overall. Also give it some more timing in the 2000-3200 range to ramp up to total abit quicker... should help on footstalling to make abit more torque to come off the line quicker

I forgot to post the dyno sheet.

man i hope you get it figured out i made 300whp and ran a 13.6 at 109.

Yeah me too

haha i made 254whp and ran 103.8 so yeah, somethign aint right there. I think its yourtune, i'd try again with the dyno tune like i said and see what happens. Recalibrate the wideband and let it eat

well to me i looks like lack of fuel on top and to advanced spark at bottom this is why your car is not pulling like he should be

best regards

I have long tubes but same exhaust ; 3" , no Cat, into free flow mufflers

The Lm-1 w/b is lying to me. Will have to recalibrate it. With the #1 spark showing a red glaze that means it's most likely leaning out but was recording 12.7:1 at WOT down the track. LIES I TELL YOU, LIES!! lol

Your are running no were near were you should. My combo and times are in my sig with a racing weight of 3400lbs. I have not dynoed my car, so I cant say for rwhp.

Unless your car is a complete pig (heavy), then you should be running in the 11's.

what are you shifting at, and a good set of slicks would bring that 60ft time down quite a bit. But then again you may bust your 10 bolt then. I am running m/t et streets and hooks wonderful, pulls the front left tire off the ground. I cut 1.58 60 foot times with my combo. I shift at 6200 and launch off of idle.

I'm shifting at 6k to be safe but I think I'm gonna up the rev limiter to 6500. My 10 bolt is not stock so it should take alot more abuse than a stocker. It has welded axle tubes, TA diff cover, Auburn limited slip with Richmond 3.73 gears, solid spacer instead of a crush sleeve. If anything breaks in the rear it'll probably be the stock axles. Man I hope the richer tune will cure my slow 1/4 mile times. I bet the guy in the tower looked at my tech card and said to himself "deer deer deer that ain't no gosh darn 383 deer deer deer"

Stock axles should be good for a 1.75-1.8 60', anything lower than that and boom gettin towed home from the track. I wouldn't use slicks with thows axles maybe some drag radials. The rear will last longer if the car dosen't dead hook, some tire spin is ok but too much is not. Be careful on how high you spin that motor until you make sure the tune is right. Bad tune plus high rpm...... BOOM! Gettin towed home from the track.

My 383 ran a 12.30 its first pass ever. Similar setup,except it was carbed. 383, AFR 195's, Comp 230/236 dur. 544/555 lift cam(hyd. roller), Performer RPM intake, 750 Holley, 700R4 w/3000 stall, 3.73 gears. That was on M/T Sportsman Pro tires. It had 1.6 60ft times

What was the trap mhp.

109 if I remember correctly

He's quite a bit slower with his combo running 104 mph. What are you running now that you've had some seat time with your setup. I would think if his car is making 382 whp he should be in the 11s for sure once he get some tires.

I dont have it anymore. That was the only time it went to the track before I sold it to my dad. That was with Hooker Super comps into a flowmaster Y pipe, and catback with a Flowmaster 3" single inlet/outlet muffler. My dad changed the setup some because he used it as a race car. Went to a Vic. Jr. intake, open headers, ect. It ran 11.50's in that form.
I think his TPI may be choking him up. That and running reg. street tires.

Oh yeah. Mine also had a Auburn diff. in the stock housing. I had axels though. It held fine. Just a FYI

my bone stock 00 trans am rear held 1.41 and 1.45 60 foots with a nitrous 383. They can hold some power on stalled auto launches..but then again some people break them

My intake is Accel Superram. I'm convinced that it was a bad tune that caused my slow times. Why? I'm glad you asked. Got into a race with an 05 or 06 Cobra from a dig on my way home from work today. Beat him by about 3-4 car lengths without the bottle. I know he floored it because I can hear that damn supercharger whining like a crying beeyatch.

LOL, good kill man. Was it cryin cause he was tying to keep up or cause you put that foot to booty. lol
Yeah just run the tune that you dynoed with till you can dail it in so you can see what the car can do on the track.

Yeah I see that now. I saw the Edelbrock base before,and was thinking you just had that,or that with their runners. My brother 85 IROC had a 406 with early TFS 23 degree heads,Comp 274 flat tappet cam, 9.5:1 comp,Accel super ram(lower too),Accel 1000 CFM TB,stock mass air with no screen,3.73 gears,24 lb injectors,with a custom chip. It would run 12.40's through the single 3". So the super ram is pretty good. I dont know anything about the Edelbrock base though. Sounds like it may be the tune to me.

It had shorties and Y pipe to a Dynomax cat-Back.

Actually the intake base that came with the Superram WAS an Edelbrock High-Flo TPI manifold. Accel was selling them with the plenum.

Just curious. Did you ever figure it out. If so what kind of et and trap?

Thanks, love the car more than you know.

I went back to the track and was getting higher trap speeds (111mph) after messing with spark and ve tables. Still in the low 13's though with no nitrous. I can easily get into the 12's with a better 60'time. I've been taking it easy on the T5 with 2.0-2.2sec 60' times. I also found that the factory snorkel intake has been restricting this engine because I had a metal can inside the snorkel hose to keep it from collapsing and the can was crushed after the first run. I trashed the snorkel crap and made my own cold air intake courtesy of the Home Depot and will be testing again later on.