Rough Boost Numbers - Novi 2000 on a 302/351

Since everyone always wants to know how much boost different pullies will make most commonly for 302/351 based motors I figure we can start a tally of different setups so that people can get rough ideas of how much boost they might see. Remember you can't directly compare these numbers as each motor is different but you can get a basic idea from these. I've collected these from what people have posted in this forum and on corral. If anyone wants to correct or add to this feel free I'll add it to the first post here. I'm assuming most of these people have atleast a 2.5 inch exhaust system but I can't track down all of the setups. You can use the ratios to see what a cog would be to a similar serpentine ribbed setup and vise versa.

Crank/Blower = Ratio = PSI @ RPM / Cubes / Mods if any / Impeller RPM

Cogged
73/29 = 2.51 = XX# @ 7000 rpm 370 heads/cam/intake 62377 (Impeller was Destroyed)
73/31 = 2.35 = 17# @ 5800 rpm 306 heads/cam/intake 48350
73/34 = 2.14 = 20# @ 6800 rpm 308 heads/cam/intake 51684
72/31 = 2.32 = 15# @ 6000 rpm 347 heads/cam/intake 49332
68/34 = 2.00 = 15# @ 7000 rpm 347 heads/cam/intake 49560

Serpentine
8.00/3.00 = 2.66 = XXXX @ 6500 rpm 370 heads/cam/intake 61360 (8 rib belt slip)
8.00/3.00 = 2.66 = 13#'s @ 5900 rpm 396 heads/cam/intake 55696 (A/A intercooler)
8.00/3.00 = 2.66 = 15#'s @ 5800 rpm 351 heads/intake 54752 (A/A intercooler (Powerstroke))
8.25/3.40 = 2.42 = 14#'s @ 6000 rpm 393 heads/cam/intake 51538 (A/A intercooler) 641rwhp
8.00/3.25 = 2.46 = 30#'s @ 7200 rpm 306 heads/cam/intake 62740
8.00/3.25 = 2.46 = 23#'s @ 6800 rpm 357 heads/cam/intake 59254
8.00/3.75 = 2.13 = 20#'s @ 6000 rpm 306 heads/cam/intake 44800 (8:1 comp)
7.75/2.75 = 2.82 = 20#'s @ 6200 rpm 306 heads/cam/intake 61853
7.40/3.75 = 1.97 = 12#'s @ 6300 rpm 393 heads/cam/intake 43512 605rwhp
7.40/3.20 = 2.31 = 15#'s @ 6300 rpm 393 heads/cam/intake 50990
7.40/3.20 = 2.31 = 12#'s @ 6300 rpm 393 heads/cam/intake 50990 (A/W intercooler) 650rwhp
8.50/3.20 = 2.65 = 10#'s @ 4500 rpm 393 heads/cam/intake 41835 (A/W intercooled) belt slip
7.00/2.95 = 2.37 = 18#'s @ 5600 rpm 302 stock 47040
7.00/3.00 = 2.33 = 16#'s @ 6000 rpm 302 heads/cam/intake 48639
7.00/3.00 = 2.33 = 14#'s @ 6200 rpm 331 heads/cam/intake 51212
7.00/3.00 = 2.33 = 13#'s @ 5800 rpm 331 heads/cam/intake 47908
7.00/3.10 = 2.25 = 19#'s @ 6300 rpm 302 heads/cam/intake 50359
7.75/3.60 = 2.15 = 13#'s @ 6500 rpm 393 heads/cam/intake 48976
7.00/3.25 = 2.15 = 16#'s @ 6250 rpm 306 heads/cam/intake 47654
7.00/3.25 = 2.15 = 10#'s @ 5500 rpm 347 heads/cam/intake 41935
7.00/3.50 = 2.00 = 12#'s @ 5900 rpm 306 heads/cam/intake 41300
7.00/3.50 = 2.00 = 11#'s @ 6300 rpm 302 heads/cam/intake 44604
7.00/3.50 = 2.00 = 12#'s @ 6200 rpm 302 stock 43896
7.00/3.50 = 2.00 = 12#'s @ 6000 rpm 302 heads/cam/intake (8 rib)
7.00/3.50 = 2.00 = 10#'s @ 6000 rpm 302 stock 42480
7.00/3.50 = 2.00 = 10#'s @ 5700 rpm 302 cam/intake 40356
7.00/3.50 = 2.00 = 9#'s @ 6500 rpm 347 heads/cam/intake 46020
7.00/3.75 = 1.86 = 8#'s @ 5500 rpm 302 cam/intake 36344



Lastly remember Paxton recommends a maximum 55,000 impeller speed. You can calculate the impeller speeds with these pulley combinations using the formula below. There are combinations in here which do spin the impeller faster than the maximum impeller speed, which is obviously not recommended. Neither the contributors or myself shall be held liable for any damage resulting from using any of the submitted pulley combinations.

(Crank pulley / Blower pulley) X 3.54 or (3.50 newer N2K) X ENGINE RPM = IMPELLER SPEED

Note: The 3.54/3.50 represents the Novi2k's internal gear step up ratio. If you have a newer Novi2k you have a 3.50 step up ratio

Does anyone have any other submissions? Please go ahead and reply with your pulley setup and how much boost you see. Also we could really use some of the 351 guys info I know a lot of you have tried all kinds of pulleys.

347, heads, cam, intake, 3.5/7 10 rib, 9# @ 6500

Added, thanks!

Are these numbers with or without powerpipes?

I would say the majority if not all are with but there is no way to verify that. That is definitely one of the most beneficial upgrades for a Novi 2000. Btw we need some modular numbers posted if anyone can supply some.

I'll round up some number's for T and S-trim's as well........this was an excellent hustler..

Definitely I recommend starting the same topic in their respective sections Brent.

6.87/3.00 = 2.29 = 16#'s @ 6000 302 tfs heads tfs intake f cam - 48639

Fomoco, are you using the stock crank pulley or a custom one?

stock crank pulley

Quote:

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Originally Posted by FoMoCo1

6.87/3.00 = 2.29 = 16#'s @ 6000 302 tfs heads tfs intake f cam - 48639

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I made 14psi @ 6200 and 13psi @ 5800 (on my 2 dyno pulls) with the same pulley combo. I have the same heads and similiar intake but more cubic inch.

FoMoCo, you need to update your time in your sig. ;)

Thanks for the input FullAuto, I added your submissions.

any body have boost #'s for stock bore and stroke 351 h/c/I
for maybe 10- 12- 14 lbs of boost and at what rpm

thanks Sherman...

It's all about flow. What kind of heads and intake are you running?

351 lightnig short block with forged pistons...vic jr heads otb, victor 5.8 intake otb, trick flow stage 2 cam, 80mm tb, 80mm mass air
1 3/4 headers 3 inch ex...
thanks Sherman

made 10 psi at 5600 on 351 lightning shortblock 9to1 T Trim w/ coggs 74 crank and 33 blower pulleys.... it made 475 rwhp and 439 tq 22 dgrees timming and 11.5 AF.

will switch too the 29 tooth I have later as I get use to it....

Made 15psi through a powerstroke diesel IC ,with 8 rib setup, 8"lower and 3" upper, 351, mild combo.

what rpm was this at, and what was done to the 351? Do you have aftermarket heads, cam?

Sorry, it was a 5800 shift with a tad belt slip. The 351 was bored .030 forged bottom end, HO stock roller cam , Worked exhaust ports on GT40X heads, on GT40 lower and upper (Lightning) 65 throttle body

http://www.nloc.net/gallery/images/f...5-503-6510.jpg

3.5/7 8 rib, 12# @ 6000


302, tw heads, rpm intake, f-cam, longtubes with 3" exhaust (for now as it's too loud) and a upr powerpipe

then 8/3.75 10 rib 306 hci 6k rpms = 20lbs. about 8:1 comp.

16 psi on a 8/3.50 10 rib setup

Without RPM of the motor or the cubic inches it doesn't really help anyone with a similar setup or trying to create one.

393 Afr 205/ TFS R intake 7.4/3.75 non-intercooled 12psi 605rwhp 6300rpm
393 Afr 205 / TFS R 7.4/3.2 non-intercooled 15psi ? rwhp
393 AFr 205 / TFS BOX 7.4/3.2 A/W cooled 12psi 650rwhp
same combo 8.5/3.2 A/W cooled 10psi at 4500rpm (belt slip)

Will have numbers on the last combo when i get rid of slip

347 Dart Block
Roush 200 Heads
Solid Roller Cam
9:1 compression

Novi 2000 blower w/ 34 blower / 68 Crank cogged setup = 15psi @ 7000rpm

Can has run 10.26 @ 140mph so far with a 1.70 60ft as the converter is too tight (launching at 3750 rpm)

Going to a 30 blower pulley. I'll update new boost numbers

306 W/E7's,GT40 intake, B cam.
Novi 2000 7.0 crank,3.5 blower 12#'s at 5900.
getting 3.25 pulley over the winter..hoping for 15-16psi

reefer,
get either a reichard racing pulley or go with a larger crank pulley. that is my opinion. sometimes worth it's weight in gold sometimes not... oh yeah it's just my opinion... oh well i had to try to get a laugh even if it was from myself...

Quote:

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Originally Posted by ssj50driver

reefer,
get either a reichard racing pulley or go with a larger crank pulley. that is my opinion. sometimes worth it's weight in gold sometimes not... oh yeah it's just my opinion... oh well i had to try to get a laugh even if it was from myself...

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I called him, he only has a 3.5 & the next size down is 2.95. I can't use larger crank pulley, I'm already very close to waterpump pulley with 7.0 pulley.

7.75 crank 3.6 blower is giving my 393 13lbs @6500.

updated

With a 7.75 crank and a 3.6 blower pulley I was making 11lbs.

Made a 3.4 blower pulley and it bumped up 2 lbs to 13. Noticed some slight belt slip up in the upper rpm ranger. I am going to assume that once the Novi starts getting up in the 50k+ RPM range that its getting harder to turn and this is with a 10 rib. I think I will switch over to a cog drive.

Anyhow it made 630 rwhp at 6200 on mustang dyno but I believe those numbers to be very conservative and I will find out Friday what the car runs at the track.

I never seen a 347ci getting more than 14-15psi of boost. Is it possible to get more?

With the added displacement of the 347, and the assumption that the 347 has aftermarket heads, you will always see less boost than say a 302 because boost is just a measure of restriction. Typically a bigger motor will have bigger ports, displace a larger volume of air through the chamber on each stroke etc. There is no magically number like 17 or 20psi that shows that the supercharger is maxed out. The only way to determine when the supercharger is maxed out for a particular combination is to calculate the impeller speed via the pulley ratio and maximum rpm of the motor.

Think of it this way, your breath represents a supercharger pullied to its maximum rpm. Blow as hard as you can into a straw using one breath without passing out :). Consider how much effort it takes for you to blow all that air through that tiny straw as you do it. Then go do the same thing using two straws. You will find it takes less effort to blow through two straws than one because you increased the area which you can blow the air through. So one straw equates to a 302, two straws equates to a 347, three straws 408, etc. That effort is equivalent to boost. You are still blowing the same amount of air each time through the various straws, it just gets easier with more straws because there is less restriction in the path of the air. So the supercharger is still pushing the same amount of air through the different engines, it just doesn't have to push as hard on the bigger cubic inch engines. This is the best example I could come up with.