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Discussion Starter · #1 ·
Hello hope everyone is having a better week then me lol so this week I finally got my car to the dyno its a 66 nova with 700r4 with a 2800 to 3200 stall and 33 spline 324 gear 12 bolt the motor is a .60 over 383 stroker 9.4 .1 compression victor jr heads and comp cam 230/240 cam with a holley stealth ram intake efi intake with dual 58 mm throttle body from what I have seen from this heads cam set up should produce atleast 370 to over 400 at the wheels my car dynod 300 hp and 317 with 34 degrees of timing the only thing we can come up with is that the intake manifold is what is checking down the power but I'm not a performance builder and don't have that much experience is that possible for a intake manifold to chock down that much power for the heads and cam not to perform the intake manifold says it can make up to 500 hp and flow 1,000 cfm any inputs criticism will be appreciated just trying to figure this out alot of money in heads and build for only 300 to wheels its a turd for the price
 

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Whose converter and how much converter slip?

What were the peak tq and hp rpm's?

What altitude, headers and how about the rest of the cam specs?

What are tire wheel and tire specs?

What EFI system?

Lastly, a picture of the curves would be helpful?
 

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Discussion Starter · #3 ·
From what I know on convertor is just 2800 to 3200 stall I'm in ca by hunting Beach so think low attitude headers are 13/4 primary to 3 inches running a 245/34/18 w Hoosier tire
616803
 

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Those two sets of curves look like they are from two different engines?

You need to get more info. Did you tune it or did the pay for tuning? And can you answer all of my questions?

You don't know whose converter your running? Were all the pulls made in 3rd gear (drive)?
 

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Discussion Starter · #5 ·
It's the same car just a before and after of of the last 2 runs after some fuel was pulled out to smooth the curve and both pulls I believe had to be made in second gear and no I do not remember who's converter just stall speed what other information would you like I payed for tuning its a holley hp efi system
 

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It's the same car just a before and after of of the last 2 runs after some fuel was pulled out to smooth the curve and both pulls I believe had to be made in second gear and no I do not remember who's converter just stall speed what other information would you like I payed for tuning its a holley hp efi system
Something is wrong - no way in hell are those two runs from the same car. Your combo should be maxing out the intake, but it should be at 6000-6200. Your HP should be able to datalog enough to determine converter slip, AFR, timing, etc. Can you send over your tune and datalog from those two runs?

The reason for looking for the converter slip should be obvious. But if you don't know why, then be advised, a crappy converter can eat up well over 100ft/lbs.

You asked for help and reasons as to why, you have all of the data - please provide and we'll help you out.
 

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One thing you need to realize is that chassis dynomometers tell you rear wheel horsepower. All these formulas that purport to relate that to crankshaft horsepower are 99 percent fantasy.

Everybody likes to sell this 20 percent driveline and installation loss, which is valid for a quite well tuned chassis. The truth is losses can run as high as 50 percent with ease.

If you really want to know how much power the engine puts on the crankshaft pull it out and take it to a facility with an engine dyno.

Fixing an engine’s power from chassis dyno runs is a lot like chasing a piñata blindfolded. You don’t know if the engine isn’t producing, or the torque converter is eating ponies, the transmission is inefficient, U-joints are binding, the rear axle is adsorbing power, the expensive exhaust has weird harmonics, the tires are gobbling power. The only thing you know is what the power delivered by the tire is.

Bogie
 

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Discussion Starter · #8 ·
Yes I know something is wrong and I wish I could give more info but I'm not a tuner I really appreciate you help and info though from what I hear the tuner that dynod my car is pretty good and has been using holley since it came out and has been tuning for for 15 uears but thats all hear say I'm new to this efi tuning stuff and don't have alot of connections in my area I have to look into how to data log and post files have not done that if I didn't have so much into this build I would just throw a 750 and victor jr intake on it and call it a day
 

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Yes I know something is wrong and I wish I could give more info but I'm not a tuner I really appreciate you help and info though from what I hear the tuner that dynod my car is pretty good and has been using holley since it came out and has been tuning for for 15 uears but thats all hear say I'm new to this efi tuning stuff and don't have alot of connections in my area I have to look into how to data log and post files have not done that if I didn't have so much into this build I would just throw a 750 and victor jr intake on it and call it a day
The EFI isn't the problem. If you want to learn something about it and not rely on the tuner then PM me with your email address.

I have nothing bad to say about your tuner because I have almost 5-10% of the info needed to make a decision. Tune and datalogs will answer a crap ton of questions and hopefully resolve a coupe of issues. A couple of time slips with tune and datalogs will get us to the 50+% of the info needed.
 

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Discussion Starter · #11 ·
One thing you need to realize is that chassis dynomometers tell you rear wheel horsepower. All these formulas that purport to relate that to crankshaft horsepower are 99 percent fantasy.

Everybody likes to sell this 20 percent driveline and installation loss, which is valid for a quite well tuned chassis. The truth is losses can run as high as 50 percent with ease.

If you really want to know how much power the engine puts on the crankshaft pull it out and take it to a facility with an engine dyno.

Fixing an engine’s power from chassis dyno runs is a lot like chasing a piñata blindfolded. You don’t know if the engine isn’t producing, or the torque converter is eating ponies, the transmission is inefficient, U-joints are binding, the rear axle is adsorbing power, the expensive exhaust has weird harmonics, the tires are gobbling power. The only thing you know is what the power delivered by the tire is.

Bogie
Thank you for your reply yes I completely understand what you are saying and possibly will have to go that route if I can't get it resolved I'm just penny pinching right now though I buy all my parts and install them myself to save money and learn more and I guess I'm learning from this experience right now 😐
 

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Discussion Starter · #12 ·
The EFI isn't the problem. If you want to learn something about it and not rely on the tuner then PM me with your email address.

I have nothing bad to say about your tuner because I have almost 5-10% of the info needed to make a decision. Tune and datalogs will answer a crap ton of questions and hopefully resolve a coupe of issues. A couple of time slips with tune and datalogs will get us to the 50+% of the info needed.
Yeah I'll shoot you a email and yes some time slips would definitely help unfortunately are track just opened back up and are limited capacity and your lucky if you get 2 to 3 runs if you are there from open to close you are literally waiting 3 hours before each run I'm considering getting a dragy to help me to see kinda were the car is at
 

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So, I don't know much, but I do have experience with a cheap converter in the 700R4.
And I can promise you, if you paid less than $699 for it. And if it doesn't have a name on it, you are losing power right there.
I got one of the 10 inch with the stall speed you stated a few years ago. It acted very well on the street, but I could never break into the 13s at the track... So one day I bit the bullet and ordered one from FTI. There are several good ones I could have got for a little less, but I was impatient and paid for one that was ready already.

This was one of the best moves I have made. The 2 converters behaved about the same. But when I hit the gas the first time, I knew something was different. It would really poured that (13.6) power down onto the pavement!

Now the same converter is behind a bigger motor, and the 3900 pound truck runs 12s.
I am very fortunate to live close to a nice 1/4 mile track, so I have never been on a Dyno.

But I do have a Freak show converter sitting in my shop, ready to go behind my next project that is waiting on parts right now.

Moral of the story is that a custom converter is well worth the money!
 

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Discussion Starter · #14 ·
So, I don't know much, but I do have experience with a cheap converter in the 700R4.
And I can promise you, if you paid less than $699 for it. And if it doesn't have a name on it, you are losing power right there.
I got one of the 10 inch with the stall speed you stated a few years ago. It acted very well on the street, but I could never break into the 13s at the track... So one day I bit the bullet and ordered one from FTI. There are several good ones I could have got for a little less, but I was impatient and paid for one that was ready already.

This was one of the best moves I have made. The 2 converters behaved about the same. But when I hit the gas the first time, I knew something was different. It would really poured that (13.6) power down onto the pavement!

Now the same converter is behind a bigger motor, and the 3900 pound truck runs 12s.
I am very fortunate to live close to a nice 1/4 mile track, so I have never been on a Dyno.

But I do have a Freak show converter sitting in my shop, ready to go behind my next project that is waiting on parts right now.

Moral of the story is that a custom converter is well worth the money!
Yeah I going to have to get some 1/4 mile times to see what's going on if the car is 13.2 are over something is mechanically wrong if it's 12.5 and under then the dyno are the tuner was off
It's so hard to find a honest good tuner in my are that does just half ass it are give up to quick on it quick
 

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You will be your best tuner soon. With the help of these guys on here!

I wouldn't even imagine tearing into an engine 6 years ago. Now I am fearless! These guys have tons of knowledge, and very generous with it. Answer their questions and you will do well.
 

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I emailed you, so shoot me one with the tune and datalogs.

I'm with excellenceAuto - I'm guessing there is a strong possibility that your converter is at issue.
 

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It looks like it was climbing well and then just flattened out. Is it possible that your injectors are not large enough or that your fuel flow/pressure is insufficient ?
 

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Discussion Starter · #18 ·
It looks like it was climbing well and then just flattened out. Is it possible that your injectors are not large enough or that your fuel flow/pressure is insufficient ?
I dont believe it is we have 36 lbs injectors and are fuel pump is rated up to 750 hp n/a and 600 on boost and had a electric and mechanical psi fuel gauge on it but yes this motor should pull to 6400 maybe more making power
 

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Some food for thought.

Note that your horsepower is uncorrected for weather conditions. Was it a hot humid day? Was it stormy? Are you at sea level?

Corrected horsepower is adjusted to standard temp/pressure/humidity/altitude by a factor called air density. For example, if air density is 90% then expect "corrected" horsepower to be 10% more in a naturally aspirated engine. It's all about how much oxygen is in a given amount of air that the engine is ingesting. Irregardless of the fuel mix, amount of oxygen present in the air is the limiting factor in production of power. This is how superchargers and nitrous make more power - by adding extra oxygen to burn more fuel. Here is a site that gives historical as well as forecast air densities at many tracks around the country. Air Density Online - Engine tuning weather If you know the day of the dyno, you should be able to get an idea of everything from the Air Density Online site except for the air inlet temp (maybe you have that logged).

Also pulling down the numbers are the water pump, alternator, and the cooling fan. Taking the belts off made about 30-35hp difference on the dyno for me. Then I went to electric water pump and fan.

With my 383 (10.3:1, AFR 195 heads, Air Gap, Quick Fuel SS830) I went 345 HP uncorrected (355 HP corrected) at the beginning. 371 HP uncorrected (391 corrected) with electric fan and water pump. 403 HP uncorrected (405 corrected) with gasket matched Vic Jr and tuning carb. 419 HP uncorrected (448 corrected) with Crower 00307 FT Solid cam, 1.6 rockers on intakes, and tuning carb. Always open headers. Note these are 4 different dyno sessions, so percentage of correction is different for each set of weather conditions. 60' ET was 1.49 1/4 mile was best 10.85 @ 122 mph. Vehicle weight was 3220 with me in it. Was a Dynojet Dyno. Went from 11.80s to 10.80s. I do have a custom converter from A-1 and a TH350 - 3.73 gears - 28" tire. Crower cam was still increasing power at 6750 but I kept that as a redline. Original XE274H was done at 6200 in my setup, but that was higher RPM than published.

Haven't heard a lot about Vic Jr. heads or know which ones you have. Not sure how many people are using them or why. Supposed to have some CNC machining but not as much as the AFRs.
 
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