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Spectra jet boat top speeds

Quicksilver

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I'm just wondering what you guys are getting for top speed with your Spectra Jet boats? Please list length/engine/pump/impeller and any other useful info.

I'm getting 62.9 mph @4450-4500 rpm's on gps with my Spectra 18, mild Ford 460, and Berkeley E pump (unsure on the impeller). Just wondering how my Spectra compares to others out there. :headscratch:
 
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Forensic

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Whats your RPMs at that speed?


79 Spectra 20 454 w/ 750CFM and headers. Dominator Pump and AA Impeller (I think)
59.9 on the GPS @ 4,300 RPM

Had the motor and pump freshened up and added a place diverter.
Runs great but something is wrong, my RPMs dropped by 1,200. :grumble:

I'm replacing the bowl real soon as a start (old bowl modified to work with the place diverter) and hope to get this figured out. 59.9 isn't bad for a heavy ass jet boat but its not good enough for me.
 

Quicksilver

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Whats your RPMs at that speed?


79 Spectra 20 454 w/ 750CFM and headers. Dominator Pump and AA Impeller (I think)
59.9 on the GPS @ 4,300 RPM

Had the motor and pump freshened up and added a place diverter.
Runs great but something is wrong, my RPMs dropped by 1,200. :grumble:

I'm replacing the bowl real soon as a start (old bowl modified to work with the place diverter) and hope to get this figured out. 59.9 isn't bad for a heavy ass jet boat but its not good enough for me.
I'm spinning 4450-4500 rpms.

What were you getting for speed before the rebuild?
 
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stickman07

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Back before my Pyle went into hybernation 13 years ago, best I ever got out of it was 72 on a Faria pitot speedo @ 5400-5500 rpm's
468, 9-1 flat tops, 0781 heads w/ 219 int, 192 exh SS valves, Comp cam, Weiand dual plane w/ Predator carb, Mallory Comp 9000 & pro master coil. Berkeley 12JG, A imp, balanced & blueprinted w/ Place diverter.

Now, was that speed true ??? I have no idea, but that's what the speedo said & seemed to be consistent. I guess we'll really see when it goes back in the water in a few weeks with the new lavorsi's, but gonna take it easy on the ol thang for a while till we're sure it's all gonna hold up ok.

I'm sure the bashin will soon begin ...


Sent from my iPhone 4S bought with UNION Dollars ! 🇺🇸🚒
 

stickman07

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Oh, 75 Spectra 20


Sent from my iPhone 4S bought with UNION Dollars ! 🇺🇸🚒
 

Maw

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Our '78 19' ran 70 even on the GPS with two aboard, full tanks and the bimini up. 454 (444 dyno BHP) with good heads, eight point something to one pistons, mild Comp cam, Performer RPM and an 850 Holley. Pump is a 12JG with a stainless AA impellor, Place diverter.

The two 20's won't be finished until late summer but both should be faster and quicker than the 19' is. Both will be in the 750 BHP range, EFI, one blown and the other a twin turbo. Pumps are the same as the 19', all three were done by MPD.

Cheers
 

spectra 224

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I would like to go faster but I need to step off my wallet first!

spectra 20
bone stock olds 455 that I severely overheated about 4 years ago!
new AA impeller last year on pump rebuild
48 mph top speed with a tail wind!
3000 rpm
 

FASTJTBT144

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19 Spectra spins a bronze mag AAA in a Tom Papp aggressior set up with tt 540 @ 5200 109 mph gps has way more to scary fast in a vee that size
 

stickman07

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Ive got it up to 82 mph so far with the re-power .... ImageUploadedByTapatalk1439216715.810980.jpg
 

Malcolm

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My '75 18 only did 54 at 4900 with an Olds and a Jacuzzi WJ B
My '76 19 did 64 with the same 455 @5000 and a Berk A
My latest '75 19 does 60 with that same Olds @ 4600 with a WJ and berk guts, AA impeller
 

Gelcoater

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Have any of you Spectra guys done work on the bottom?
Taken a straight edge to see if the bottom is straight?
I can't help but suspect these boats built in the 70s and 80s and sit on a trailer a lot can develop some warping?
 

Forensic

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Have any of you Spectra guys done work on the bottom?
Taken a straight edge to see if the bottom is straight?
I can't help but suspect these boats built in the 70s and 80s and sit on a trailer a lot can develop some warping?
I haven't but have heard enough to believe that the Spectra's were layed up with hook in the bottom.
 

stickman07

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Has K&N's inside the scoop. Haven't seen an issue in 2 seasons with it.
 

AzGeo

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Every time a customer wanted that scoop I had to prove why I didn't use them . The last deal was a 540, 8-71, pump gas 20' V-drive cruiser . That scoop with two metal (3" tall) flame arrestors inside, the motor would only make "zero/one lbs of boost', 102 MPH @ 6000 RPMs . We took the scoop off, reinstalled the metal flame arrestors and the boat ran 114 MPH @ 6700 RPMs . (no other changes) I have had similar results with blown and unblown powerful motors .

If you are not 'actually making boost/airflow', then it may work, but why run a blower .

I see them all the time on this lake, on blower motors, and I wonder why people go for 'looks', instead of performance . Sure, they are FINE on hot rods, most of them are never driven at WOT anyway ........

Just a 'heads up', on what I have found to be true .
 

SPECTRALEN

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I haven't but have heard enough to believe that the Spectra's were layed up with hook in the bottom.
I have seen posts by boat builders on here and other sites saying no manufacturer puts in a hook intentionally. I checked my bottom with a straight edge and she is pretty flat. I think it's all about how the boat is sitting on the trailer and for how long. I would also think the hull that's layed up thick and heavy will probably hold its shape better.

Speed wise, 1977 20, rebuilt 460 w/ little bit of cam, performer intake, edle 600, breakerless ign., and the rest stock. Rebuild on 12jc and I'm gps'd at 55 and about 4650 rpm. I put some weight into the stringers, floor and interior with everything wood getting covered in cloth or mat with resin. I just bought a 750 edelbrock and want to see if that does me any good.
 

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namba860

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My 21 Centurion same boat as a Spectra. 512 BBC spins a (A) impeller at 5200 RPM and goes 62 mph
 

nrbr

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I pulled a massive hook out of the bottom of my 77 20. Strakes were not quite parallel with the keel so I did a little work to those. I have a 496ho with a bravo but haven't run it yet. Hoping it does 75 or I'll flip it back over and change more :)
 

Spectra18

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My spectra easily hits 5,500 to over 6000 rpm... is that the norm?
 

SPECTRALEN

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My spectra easily hits 5,500 to over 6000 rpm... is that the norm?
If your motor and pump are close to stock, It sounds like your pump is wore out or the intake on the bottom of the boat isn't letting the pump load properly.

Any idea of your MPH? GPS with phone?
 

Spectra18

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If your motor and pump are close to stock, It sounds like your pump is wore out or the intake on the bottom of the boat isn't letting the pump load properly.

Any idea of your MPH? GPS with phone?
I know in 2005 an aggressor impeller was placed and berk was rebuilt. Any suggestions for yearly maintenance ? Only thing I've done is greasing.
 

Quicksilver

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My spectra easily hits 5,500 to over 6000 rpm... is that the norm?
I think I've only gotten about 5200 rpm out of my engine, which was 63 mph. Spectra 18, mild Ford 460, Berk E pump, A imp. Rpms will vary depending on what imp you are running and a worn pump will turn more rpms.
 

Quicksilver

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I know in 2005 an aggressor impeller was placed and berk was rebuilt. Any suggestions for yearly maintenance ? Only thing I've done is greasing.
Have you added oil to the bowl? I usually top off every year and inspect the shaft for play.
 

Riverbound

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I'm just wondering what you guys are getting for top speed with your Spectra Jet boats? Please list length/engine/pump/impeller and any other useful info.

I'm getting 62.9 mph @4450-4500 rpm's on gps with my Spectra 18, mild Ford 460, and Berkeley E pump (unsure on the impeller). Just wondering how my Spectra compares to others out there. :headscratch:
That's pretty much what I got and my old Spectra and I had the same combo.
 

Spectra18

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Should I expect more horsepower from edelbrock carb/manifolds on a ford 460.
 

Quicksilver

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Should I expect more horsepower from edelbrock carb/manifolds on a ford 460.
What carb and intake are you using?

What heads do you have? Ford heads are not known for flowing good. D0VE heads were good stock heads with some professional porting. D3VE are okay, but aftermarket heads are where you will get the best hp gains. It doesn't matter what carb and intake you have if the heads don't flow good.
 

krusn56

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My 18' hits 70 at about 5100. I have a 466 BBF... Has some mods. Running thru bolt logs with snail step cut off. Pump is berk JC A-imp, aggressor 9/ stuffer, 2*wedge up, straight snoot 4* pin an diverter. Has rock grate with HTP bolt on shoe/plate set up at 3*. I have full interior, hatch, sound system an 30g belly tank.



 
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