before/after 383 dyno results

[cgarb]

I feel that I have a good deal more knowledge about engines than the average racer that I race with, but hanging out in here gives a normal Joe an inferiority complex at times. Some guys in here have a huge wealth of knowledge. It nice of those who share open and honestly.

[PRH]

Not that this means anything at all...... it’s more just a comment about what I’d use for a combo like this........

I have a set of dyno headers that look just like the ones in the previous pic......
Mine are 1-7/8 > 2 x 3.5” collector that I use for strokers in that 600hp+ range.

We also have straight 1-5/8 x 3, 1-5/8>1-3/4 x3, 1-3/4>1-7/8 with removable collectors, and 3 & 3.5 collectors to go through them.

For the most part, we’ll use whichever ones are closest to what will be used in the vehicle.

And then the experimentation starts if the motor seems to not be making what it was expected to.
The different headers almost never really “fix” it, but sometimes you’ll see a worthwhile gain with them....... or the results may help make decisions about what else to change.

[NewbVetteGuy]

Sunoco 110 is “Standard”, right? Standard is purple.

What gaz did you use for the first test session?

Will it be the same for the next test?

Yes, standard is purple and that's what the local track has but his pump says Supreme. Supreme is blue.
We used VP blue on the first session and we will use it again. It's what Joe keeps there.
I may bring some Sunoco 112 to make a pull or 2 just to see if there's any difference.
He tried some Q16 in the car, so he'd try that if I wanted.

Randy

VP Blue?
C16?

Resurrecting the fuel debate...

Why not VP CHP or CHP+? -If going oxygenated why not go REALLY oxygenated if the fuel system has the room?
-I was pulling some spec sheets today, MS109 is 5% oxygenated, CHP is 10% oxygenated and CHP+ is 18.34% oxygenated, leaded 107 octane. VP recommends a 6-8% fuel enrichment with the CHP+. The CHP and CHP+ are actually cheaper than MS109 and Q16, too: $85 / 5 gallons retail.

-Given that CHP/ CHP+ are designed for dirt track GM602 / GM604s to make max power seems like it might be appropriate for this 383...

(I'd LOVE to see a back-to-back dyno of a fuel with this much oxygen content....)


Adam

[randy331]

Don't think I'd be ok with a MON of 99 on a 13-1 engine with any sort of ve .
The spec sheet didn't say, but I think it's oxygenated with alcohol.??

If it makes the power improvement I'm thinking he'll have some car sortin to do before chasing a few more HP.
I'll probably do a Q16 test for him just so he has a tune up for it if he wants to run it.
But, I'm gonna suggest vp blue or Sunoco Supreme.

Randy

[GARY C]

Don't think I'd be ok with a MON of 99 on a 13-1 engine with any sort of ve .
The spec sheet didn't say, but I think it's oxygenated with alcohol.??

If it makes the power improvement I'm thinking he'll have some car sortin to do before chasing a few more HP.
I'll probably do a Q16 test for him just so he has a tune up for it if he wants to run it.
But, I'm gonna suggest vp blue or Sunoco Supreme.

Randy

Yes it is ETBE, if you look at the SDS sheet,
CAS# 637-92-3,.... 211-309-7,.... 2-Methyl-2-ethoxypropane
https://vpracingfuels.com/wp-content/up ... ulated.pdf

ETBE Info
https://en.wikipedia.org/wiki/Ethyl_tert-butyl_ether

MTBE would read lke this
CAS# 1634-04-4,.... 216-653-1,.... 2-Methoxy-2-methylpropane
https://drive.google.com/drive/folders/ ... kFWlM20w-X

MTBE Info
https://en.wikipedia.org/wiki/Methyl_tert-butyl_ether

[Olds455]

Sorry for the side track...but why is it that they step the tubes larger as you go down the primary? Wouldn't stepping the tube smaller gain velocity as the gas travels down the pipe? I think about things in ways that relate to what I do...if you step water pipe down in size you gain pressure. I guess back pressure is not your friend in some cases...but as the hot exhaust gas cools wouldn't you need less pipe for it to travel out?

Pretty sure back pressure is never your friend as far as exhaust goes. You want as little as possible no matter what. Street cars don't "need" a little bit of backpressure like many have repeated over the years. At least that's how I learnt it.

[Olds455]

I feel that I have a good deal more knowledge about engines than the average racer that I race with, but hanging out in here gives a normal Joe an inferiority complex at times. Some guys in here have a huge wealth of knowledge. It nice of those who share open and honestly.

You can't just make a generalized statement like "it gives normal Joe's an inferiority complex" From what I've seen, it's not the normal Joe's with the inferiority complexes around this forum. It's the other guys that think they're too good to talk to or share with normal Joe's.

[Olds455]

I probably shouldn't post right after I wake up. I wrote "inferiority complex" while thinking "superiority complex". Whoops!


Though I'm not sure that entirely explains it, either.

[In-Tech]

I probably shouldn't post right after I wake up. I wrote "inferiority complex" while thinking "superiority complex". Whoops!


Though I'm not sure that entirely explains it, either.

LOL, I don't know of anyone on this forum that has a superiority complex. I think it boils down to "ask the right question and you'll get the right answer"

[naukkis79]

Sorry for the side track...but why is it that they step the tubes larger as you go down the primary? Wouldn't stepping the tube smaller gain velocity as the gas travels down the pipe? I think about things in ways that relate to what I do...if you step water pipe down in size you gain pressure. I guess back pressure is not your friend in some cases...but as the hot exhaust gas cools wouldn't you need less pipe for it to travel out?

Exhaust gas velocity is constant MACH1 at blowdown. As velocity is constant pressure drops when pipe enlarges which creates wanted suction wave.

Gas velocity depends on pressure ratios, and when pressure ratios are above 2:1 choked flow is achieved - flow velocity is as high as it could be.

[cgarb]

I said "a normal Joe" as in myself.

[NewbVetteGuy]

Don't think I'd be ok with a MON of 99 on a 13-1 engine with any sort of ve .
The spec sheet didn't say, but I think it's oxygenated with alcohol.??

If it makes the power improvement I'm thinking he'll have some car sortin to do before chasing a few more HP.
I'll probably do a Q16 test for him just so he has a tune up for it if he wants to run it.
But, I'm gonna suggest vp blue or Sunoco Supreme.

Randy

Yep. My bad. I should've gone back to the beginning of the thread and re-read what your CR was... Got busy reading fuel specs and got excited by the prospect of such a highly oxygenated fuel appropriate for so many typical street 383s in the mid 9 - low 10 static CRs. Shame VP doesn't make a higher octane fuel with this much oxygen added...


Adam

[Walter R. Malik]

Don't think I'd be ok with a MON of 99 on a 13-1 engine with any sort of ve .
The spec sheet didn't say, but I think it's oxygenated with alcohol.??

If it makes the power improvement I'm thinking he'll have some car sortin to do before chasing a few more HP.
I'll probably do a Q16 test for him just so he has a tune up for it if he wants to run it.
But, I'm gonna suggest vp blue or Sunoco Supreme.

Randy

I see you have used the gasoline that many of the traveling oval track & road racers use ... "Late Model Plus".

They use it mostly because it repeats almost everywhere and travels well to not become "stale".

[PRH]

At this point....... I’m just waitin for some numbers

[randy331]

At this point....... I’m just waitin for some numbers

Coming soon to a thread near you !!

Randy