Not sure wether or not to be happy or a little dissapointed. but here are the dyno results i was expecting it to be a little higher. Here is the other thread on the spec of the motor.
https://www.thirdgen.org/forums/tech...new-motor.html

Also the dyno showed that the vaccum secondaries arnt opening all the way. Not going to adjust that till i get my new rear.

And I only have single 2.5 in exchaust which could be affecting it to.
184 HP at 6,000 this is to rear wheels
What do you guys think.

 

I'd shoot myself honestly. The exhaust is definitely holding you back. Really need to know more about the combination to have a good opinion though.

Edit: Have you figured out your issues from the other thread?

 

Dynos have a way of humbling you don't they? I'd expect a bunch more HP to the rear wheels even though I have no idea of what your setup is. I'm sure the guy doing the dyno HAD to tell you it wasn't running right..didn't he?

I can believe the secondaries weren't opening at all, not just partially. I would think you'll need to sort out the carb, timing and jetting and try it again. I'm confident you'll see a vast improvement!

EDIT: -And that exhaust won't hold it back NEAR that much...

 

we'll right now he said about being conservative untill I get a couple things like the new rear cause he said that could change the secondaries becasue of the load on the motor would change so no sense in chaging the spring yet. he said timing could problably go up another 2degress. Oh and on the secondaries it was reading like 1.8 he said it should be close to 0. He also stated that fuel air ratio is almost perfect you do see it lean out on the graph where he let off the gas.

and as far as the exhaust goes the engine builder siad that the exhaust is not doing the cam justice. The guy with the dyno could say for sure how much improvement I could get out of it but he told me about a guy that didnt like his headers put a different set on and lost 30hp.

 

the timing yeah. The timing was fluctuating at idle. the guy who has the dyno also has a dist. machine and was able to get that right so now I have 16 degress at idle and 36 max right now.

What more would you like to know??

 

What are the specs on your cam? Are your heads ported old school heads(double humps) or aftermarket? How big is your converter? Big stalls eat power. Unless I'm missing something, you gave very vague information, and wanted us to tell you if it was up to par. What kind of power were you expecting, serious question.

 

From the motor thread, you have RHS 200cc heads, which arent bad heads. Dont seem to know what the cam is but if its .530 lift like you think, and near 300 duration advertised, then it should run pretty hard. Explains why the peak was at 6000 rpm, that duration cam and heads should peak atleast that high. Intake may be holding it back some and the exhaust definately is, but i dont think you'd see 100 hp out of it.

You sure that thing is running on all 8 cylinders? Is it really a 385? On a mustang dyno that 184hp would be low 200's on a dynojet but thats still 100-150+ hp lower than what you'd expect.

 

I don't like those numbers at the bottom. Is that 17:1 A/F mixture under load or did it record as a maximum after the throttle was released? If the number stayed around 12 during the WOT run then that's good. If the number was climbing to 17 during the run, the engine is running lean enough to start melting pistons.

 

yes everything you said is dead on from what I was told. When i picked up the motor from the guy who built it said it should be about 400 to 450hp motor. I know that is a fly wheel number but didnt think i would be losing this much.

Dont konw who to double quote but to answer other questions the stall is a 3000.

The fuel air ratio was around 12's on the whole run it went to 17 when letting off the pedal.

The other thing I was wondering about exhaust is on the old motor it was ok as far as loudness goes but on the motor it's like 5x louder does this mean anthing as far as not being enough.

BTW the intake is a edelbrock rpm.

 

probably have more compression now so its gonna be louder but that motor wants atleast a 3" catback but I"d do 3.5 if its suppose to be over 400hp. 184 at the tires doesnt sound much better than a stock L98. or even LB9. Something doesnt add up here.

You really need to find out what the cam is. If you can ask the builder for the specs that would be great, and ask if he degreed the cam in.

What size carb is on it? I'd use atleast a 750

 

wow thats crazy on the power you made

u should replace your 2.5 exhuast that show be limiting your power also... i heard once from a friend that he swtich from 2.5 to a 3in and got some more power out from his engine (he was in the 400rwhp)

i would say to check your timing and make sure your trans and rear diff gears are matching the combo set up u got in the engine...

 

yes the builder says the cam is degreed in and he reccommended that i put in 4'11s. still has the stock 323s but that wouldnt change the hp number to rear wheels would it?

I was thinking of doing dual 3'' out the side befor rear tire with long tube headers.

edit: from what i remember the cam was 500 lift and 280's duration @50 with the 1.6 rockers he said it has a 530 lift. card is a holley 750 daul feed single pump.

 

if those are 1 1/2 primary headers, they might be holding you up too. i hope that pop out of the carb isnt a wiped lobe on the cam.

 

At this point the best advice I can give you is get that exhaust system squared away. Are you running 1.5" headers?

 

I agree something is definately not right here. I made 181 RWHP/268 RWTQ on a Mustang dyno with a bolt-on 305 TBI using a single 2bbl TBI. The cam and heads are miss-matched with the intake & exhaust and compression ratio, but not 100 HP worth. Even a single 2.5" exhaust should have no issue making atleast 270 RWHP. However it might not be a bad idea to measure the exhaust backpressure to find out if you have a muffler that has a collapsed baffle or something.

Even 1.5" primary headers shouldn't be a huge restriction to power either. I have a 4.7 Dakota making 290 RWHP with 1.5" primary shorty headers dumping into dual 2 1/4" pipes.

 

here are the headers that are installed.

http://www.summitracing.com/parts/BIG-11102FLT/

The popping out the carb has since been fixed it was a timing issue.

what intake do you guys reccomend.

also as far as back pressure arnt the tools to check that expensive. And i have a 2.5 in exhaust dump I could install where the cat is supposed to be would that help to see if that is a exhaust issue of course I would have to have it dyno'ed again.

 

Wow....if that's correct.....duration in the 280's at .050...way too much for street use IMO. What RPM range was this engine built for again?

 

^^^^
what he said, if its indeed 280's at .050 take that out immediately... guys running 434" motors to 7K rpms dont use near that much.

HUGE mismatch in camshaft/intake/cubes/heads

 

I missed that, thought I saw 280 advertised, which is 220-224 @ .050 on most cams. If it really is 280* @ .050, that is a monster that is way wrong for this engine.

 

You're not even making 184 at the wheels. That number hasn't been weather corrected. If it was, you'd see around 175rwhp. The torque is even more miserable a 188.

Either there is something VERY wrong with the dyno, or VERY wrong with the engine. What's strange is that the torque and HP peaks are where they should be, and it's nearly impossible for a 383" engine (firing on all 8) to make that kind of power at those peaks.

Does the engine feel like it's only making 200hp? If not, find another dyno with someone who knows what they're doing. If it does feel weak, you've got MAJOR issues. Header swap, intake swap, timing, it won't be any of that little bullshit so don't waste your time.

 

If the cam is actually a 220/224 duration at .050, it should idle pretty smooth and make tons of power up to 5500. If it's 280 at .050...ditch that cam and give it to a dirt track racer.

Also, the dyno sheet you posted has too much useless info IMO. I want to see RPM, torque, HP and A/F ratio on a 2000-6000 RPM scale. That info would be more useful to me at least and tell me more about how it's really running. Like above - something's very wrong....

 

I am problably wrong about the @ 50 but i do remember him giving me a number in the 280's. Let me try and talk to him later this week and see what he says. Also there is A/F ration in there its the black line. and there is HP numbers also.

the motor feels strong it will put you back in your seat.

 

I would imagine he said seat to seat duration or .006" lift regarding the camshaft. Looking over your exhaust system IMHO you need everything from the headers on back upgraded. Again IMHO the exhaust system is one of the most important parts to realizing good horsepower.

Check out this thread and Dyno Don's post. I am making well North of 500hp with Dyno Don short tube headers. I have the dual cat version.
https://www.thirdgen.org/forums/exha...y-headers.html

 

So I talked to the guy again with the dyno he said I shouldnt do any other upgrades till i do a exhaust upgrade.

what do you guys reccommend. I was thinking long tube headers with three inch coming out the side before the back tires. but what do i do for mufflers?

 

Right off the bat, Unless it's a drag car, I'd say ditch the LT header idea due to clearance issues. There's very few LT setups that give enough clearance for daily street use- do a search and you'll see I'm not exaggerating here...especially on a lowered car. For any kind of remote clearance with LT headers, It'll involve expensive $$ ovalized tubing.

IMO Dyno Don's shorty 1 3/4" headers to be the best compromise, unless you can find a used set of SLP shorties.
Is this the same guy that wants you to change rear gears etc? The same guy that still hasn't provided any meaningful cam specs? Hey I'm not trying to bash you at all, but I'd quit trusting this guy so much...just M.O.....Please give anyone here your actual cam specs, compression etc..

And at what RPM is the A/F ratio lean or rich? What's you're HP at 5200 RPM? Get my drift?

Sorry, but an exhaust change (or rear gear change) -just ain't gonna make up fo the HP and TQ you're short of now...

 

ok i got you now.

No the builder and the dyno guy are two different people. I'm going to be going by the builder's house this week. Prob. wed. How much are dyno don's headers I went to the link above and only seen a pic.

Oh and someone metioned early about it being weather corrected and it was.

 

Well, I'll tell you now they're not cheap. If you search one of my posts, I think there's a price in there. I think your 383 has A LOT more potential than what you're seeing. Trust me, If you go way back in my own posts, I trusted the original builder of my own engine (Gustaf) - and I regretted it. Been there, done that - and I understand your frustration.

Just tell this builder you need SPECIFICS on the engine. Cam specs, compression - everything he can recall. You need a baseline to go by...

 

ok will do. I know the CR is 10.4

what is the max HP a motor can loose by exhaust in you opion.

 

If you pulled 250 RWHP, I'd think you had a serious exhaust restriction....but I have no idea how restrictive your exhaust is since IMO you're no where the potential of 383 NA cubes...again, just M.O., I invite others to chime in though...
10.4 is a great compression ratio for a pump gas 383.....

 

i think your motor would benefit from some larger headers & dual exhaust. you have good flowing heads, a stroker useing more air, a long duration cam & then trying to get it to breathe through 1 1/2 headers into single 2 1/2 pipe. is the cat still in there? are your valves adjusted properly? maybe the comment about the dyno not being accurate is an explanation?

 

No cat.

And I was at his place the next day and he was dyno a dirt track car. It was a 355 running race fuel and he was at 210 even running like crap in top end.

 

damn that sucks dude. I make double that with my 05 cadillac lol

 

I'm not buying the magic on this one. That motor would be sending you obvious "I'm not running right" signals to lay down a number that low. Mustang dynos can spit out some really awful numbers if they're not set up and calibrated right. Example:

[IMG][/IMG]

Would you believe that pathetic 258HP engine pushed a 4000 lb. GTA through the traps at over 113 MPH throught a stock 700R4 automatic transmissions? You should because it did and on the same day the dyno run was made. I hand-wrote the approximate RPMs becuase the dyno was calibrated relative to MPH (worthless!!). If you look at the torque curve and apply the old HP = (TQ*RPM)/5252 you'll see the true outputl of the motor (around 400HP).

But yours is even worse. Both the HP and torque numbers are in the toilet for a hotted-up 383. Which makes me suspect all the more that those numbers are whacked, plain and simple. There is just nothing in what you posted that explains why your motor should actually be as weak as the dyno says. Throw the dyno printout in the trash and take it to a dragstrip.

The MPH number across the stripe will tell you the truth. If you're only trapping 85 MPH then OK, maybe the dyno was right. I suspect that won't be the case, though.

 

Yep, take it to a track and see what it does mph wise.

 

It absolutely was NOT weather corrected. If the dyno operator told you it was, demand a refund. I highly suspect an idiot dyno operator here.

Like I said in my first post, the peaks occuring where they are and the overall power from that size engine is nearly impossible. I'm very familiar with Mustang dynos, and it appears this operator doesn't have a clue.

There are quite a few very reputable LS1 shops within an hours drive of York. Im sure you get on one of their dynos and a get some real numbers.

 

i wonder how much different the numbers would be? its pretty hard to believe those low numbers.

 

Damon might just be right...I never considered that maybe the dyno wasn't set up properly. That's why I commented on the way the whole graph was set up in the first place. Silly me, I assume people that are allowed to set up expensive equipment like that actually know what they're doing, but in this case maybe not.

I also agree with Damon and Marc 85Z28 that it seems like you'd know if it were acting as much like a slug as those dyno numbers would seem to dictate....

I had my car on a mustang dyno, and I didn't see numbers like that...if set up correctly, it gives you pretty darn accurate results although usually humbling....but NOT THAT humbling unless I was running on 6 instead of 8 cylinders.

As I recall, (if set up correctly) you can even simulate a 1/4 mile run on a Mustang dyno.

 

Do you know of one that you went to and what do they charge.

Thanks for all your input guys I diffenitly got some thing to do.

The close drag strip I have around here is maple grove. Also I have no idea when they do like test and tune days. Also I only have the 10 bolt 1 tire fryer in there lol. Or do u think that will be ok just for a test run.

 

One wheel peel is fine. You're looking for trap speeds, not times. Dont focus on getting a super awesome launch, just get a clean one.

 

Your best bet would be Rapid Motorsports in Reading.

Or you could choose from this list:
http://dynotesting.com/chassis-dyno-...-dynos-pa.html

I'll be at the NHRA race at Maple Grove this Sunday. If you're going, we could meet up. I think my butt dyno is calibrated a little better than the one you originally went to. I can tell you in 10 seconds if you're making 200, 300, or 400+hp.

 

keep us updated on your mph when you go and race

 

OK so I got to talk to the builders and are as follows

500 lift with 1.6 rockers = 530 lift
Advertise 290
@.50 240
Also it's a custom cam.

He also stated that the dyno I went to is "GREEDY" so to me that means not calibrated 100% right.

Took the car out last night ran great. was crusing in 1st gear at 3grand when I mashed it she squated in the rear and took off.

 

Really???? The car should have gotten sideways romping on it at that rpm in 1st gear.

 

I thought that to cause on my last motor it would spin the tires doing that but since the last motor I have gotten a biiger stall and adjust my TQ arm also. So I was thinking it might have been from the TQ arm change.

 

Id have to say your combo is mismatched, not setup correctly, not running right or its just complete junk (no offense).


Before i swapped in my carb converted LT1, I had a 355 2-piece RMS motor with Dart World Sportsman II iron heads completely stock and a mediocre Crane flat tappet cam 215/215 @ 0.050 .444/.488 lift with 1.5 rockers, 1 5/8" Hedman 68470 shorty headers and a 2.5" to 3" y-pipe and 3" magnaflow catback and the car laid down 275rwhp and 330rwtq.


First of all...Flowtech headers are JUNK. 1 1/2" primary headers on a big port head? and a single 2.5" I-pipe setup? Why? Well either way...even with 1 5/8 or 1 3/4" headers and a full 3", you wont pickup 100rwhp...no way...so something is seriously wrong....

Now i have a stock LT1 shortlbock with hand ported stock heads and a just a custom grind cam and my car will "light up the tires and go sideways" even from 2nd gear on 315/35/17 street tires on the back.

Id seriously check to make sure the cam in there IS what the builder says it is...and if it is, pull it out and throw it in the garbage, because its not your bottom end OR your heads that are holding you back...

Basic bolt-on 305 cars make more power WITHOUT headers...stock manifolds man. My buddies 89 Iroc put down 215ish RWHP on stock manifolds out of his LB9, and all he had for mods was a stock LT1 cam and a 3" catback.

 

as far as RWHP goes can I compare my car to my truck.

I have a 06 silverado 5.3L with 3.73's posi. i have read they get about 225 to 250 RWHP.

 

That is stock....My 06 5.7 Hemi made 285/301 with long tube headers and a tune. With a mild cam upgrade, e-fan, and CAI it made 378 RWHP

 

So I've decided that I'm going to try and take my car to Cecil county MD on a wed. night for test and tune. But I got a couple things to solve first.

1. When getting on the high way if I get on it to the floor the car seems to be running out of fuel. Going to try and replace the stock line from pump to carb because it is half colapesed at one spot. I have some soft fuel tubing I can use. If that doesn't fix it i guess I'll have to try a bigger pump.

2. I need to get a brake controler for my truck cause the trailer I'm going to borrow has electric brakes.

3. And finaly I need to see if they require helmets.

 

Better than a 14 second pass and you need a helmet, but they're OK with just seeing it in the passenger seat usually. Roll up camming hard with slicks and they'll scrutinize a little more. I'd highly recommend aborting after the 1/8 on the first run to avoid getting kicked out for lack of equipment. If you trap less than 90 in the 1/8, run it out for the next pass(es).

 

lets get back to my vaccum secondaries. the guy with the dyno says there are not opening all the way. I called up holley and they said about the paper clip trick. so i did some searching and seen someone say about putting a little grease at the top of the rod. If they are not coming open all the way how much HP could it be robbing.