WELCOME TO RIVER DAVES PLACE

Spectra jet boat top speeds

Quicksilver

Well-Known Member
Joined
Oct 12, 2011
Messages
354
Reaction score
163
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:
 
Last edited:

Forensic

No Title
Joined
Nov 11, 2017
Messages
1,827
Reaction score
471
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

Well-Known Member
Joined
Oct 12, 2011
Messages
354
Reaction score
163
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?
 
Last edited:

stickman07

Well-Known Member
Joined
Jan 25, 2010
Messages
822
Reaction score
34
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

Well-Known Member
Joined
Jan 25, 2010
Messages
822
Reaction score
34
Oh, 75 Spectra 20


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

Maw

Dont re Member
Joined
Jun 9, 2008
Messages
1,609
Reaction score
1,646
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

Well-Known Member
Joined
Nov 4, 2010
Messages
65
Reaction score
1
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

Well-Known Member
Joined
Jan 28, 2010
Messages
1,116
Reaction score
63
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

Well-Known Member
Joined
Jan 25, 2010
Messages
822
Reaction score
34
Ive got it up to 82 mph so far with the re-power .... ImageUploadedByTapatalk1439216715.810980.jpg
 

Malcolm

Well-Known Member
Joined
Aug 29, 2012
Messages
121
Reaction score
14
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

Well-Known Member
Joined
Sep 26, 2009
Messages
21,606
Reaction score
36,018
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

No Title
Joined
Nov 11, 2017
Messages
1,827
Reaction score
471
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.
 

AzGeo

Fair winds and following seas George.. Rest Easy..
Joined
Jan 28, 2009
Messages
8,298
Reaction score
7,921
Ive got it up to 82 mph so far with the re-power .... View attachment 426149

just the flame arresters and NO SCOOP ? I can't get blowers to RUN with that scoop on them . The rear carb gets no air . Even 'high reving tunnelrams' won't breath thru those for me .
 

stickman07

Well-Known Member
Joined
Jan 25, 2010
Messages
822
Reaction score
34
Has K&N's inside the scoop. Haven't seen an issue in 2 seasons with it.
 

AzGeo

Fair winds and following seas George.. Rest Easy..
Joined
Jan 28, 2009
Messages
8,298
Reaction score
7,921
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

Well-Known Member
Joined
Jun 26, 2008
Messages
385
Reaction score
154
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.
 

Attachments

  • 100_1624.jpg
    100_1624.jpg
    96.1 KB · Views: 192

guest hs

Well-Known Member
Joined
Jul 15, 2010
Messages
6,288
Reaction score
6,837
My 21 Centurion same boat as a Spectra. 512 BBC spins a (A) impeller at 5200 RPM and goes 62 mph
 

nrbr

Well-Known Member
Joined
Jul 4, 2013
Messages
1,418
Reaction score
921
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

Well-Known Member
Joined
Jul 21, 2014
Messages
1,134
Reaction score
1,487
My spectra easily hits 5,500 to over 6000 rpm... is that the norm?
 

SPECTRALEN

Well-Known Member
Joined
Jun 26, 2008
Messages
385
Reaction score
154
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

Well-Known Member
Joined
Jul 21, 2014
Messages
1,134
Reaction score
1,487
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

Well-Known Member
Joined
Oct 12, 2011
Messages
354
Reaction score
163
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

Well-Known Member
Joined
Oct 12, 2011
Messages
354
Reaction score
163
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

Banned
Joined
Sep 26, 2007
Messages
26,751
Reaction score
19,204
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

Well-Known Member
Joined
Jul 21, 2014
Messages
1,134
Reaction score
1,487
Should I expect more horsepower from edelbrock carb/manifolds on a ford 460.
 

Quicksilver

Well-Known Member
Joined
Oct 12, 2011
Messages
354
Reaction score
163
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

Well-Known Member
Joined
May 25, 2013
Messages
59
Reaction score
15
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.
ym931_zps590de07a.jpg

ymur4_zps27841b9d.jpg

output_oFeG87_zpsfb5cmgku.gif

riv6_zps5782d2af.jpg
 
Top