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| | |-+  Switching from 45drla to 48 drla?
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Author Topic: Switching from 45drla to 48 drla?  (Read 3628 times)
tezer
Jr. Member
**
Posts: 94


« on: March 29, 2012, 18:41:00 pm »

I have a new engine I'm going to build,and i was wondering
if there is much increase in hp if i switch from 45 to 48 this is normal carbs not tri jet
and its going to be run whit 40mm vents
is it wort the extra money?

the engine is going to be
94 pistons and barrels
84 mm dpr crank
Cb super pro heads whit fluff and buff
fk 87
1-5/8 merged header

i also maby is going to change to bigger header!

what you guys think?
« Last Edit: March 29, 2012, 18:53:41 pm by tezer » Logged
Torben Alstrup
Hero Member
*****
Posts: 716


« Reply #1 on: March 29, 2012, 20:01:30 pm »

Most likely about 10 hp more.

T
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tezer
Jr. Member
**
Posts: 94


« Reply #2 on: March 29, 2012, 21:05:53 pm »

10hp then its worth the money Smiley

Torben Alstrup you are a man whit experience in motors
what do you think shud i switch to a bigger exhaust?
this is going to be a weekend car and not a daily driver!
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Zach Gomulka
Hero Member
*****
Posts: 6991


Don't piss down my back and tell me it's raining.


« Reply #3 on: March 30, 2012, 01:38:37 am »

What heads do you have?
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Born in the '80s, stuck in the '70s.
tezer
Jr. Member
**
Posts: 94


« Reply #4 on: March 30, 2012, 06:20:35 am »

Cb performance super pro heads
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Torben Alstrup
Hero Member
*****
Posts: 716


« Reply #5 on: March 30, 2012, 08:50:36 am »

10hp then its worth the money Smiley

Torben Alstrup you are a man whit experience in motors
what do you think shud i switch to a bigger exhaust?
this is going to be a weekend car and not a daily driver!
The combo has potential for about 210 hp. A 1 5/8" header begins to brake hard at about 195 hp. So yes I think you should switch to a 1 3/4" header.
T
« Last Edit: March 30, 2012, 11:16:58 am by Torben Alstrup » Logged
tezer
Jr. Member
**
Posts: 94


« Reply #6 on: March 30, 2012, 21:44:25 pm »

i will follow your advise torben and get a bigger header!
i can get a 1-7/8 header for a god price but i think that is to big!
or can it be used?
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Torben Alstrup
Hero Member
*****
Posts: 716


« Reply #7 on: March 31, 2012, 18:34:38 pm »

Your choice. But for the engine size and parts the 1 3/4" is better suited. You will get more usable power.

T
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tezer
Jr. Member
**
Posts: 94


« Reply #8 on: March 31, 2012, 18:39:42 pm »

Will be losing to much on low rpm right?!
i think i bay a 1-3/4 I'm not going to be cheap on this motor so i just bay what is best for my motor size!
thanks torben for your help!
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Torben Alstrup
Hero Member
*****
Posts: 716


« Reply #9 on: April 01, 2012, 15:36:37 pm »

Will be losing to much on low rpm right?!
i think i bay a 1-3/4 I'm not going to be cheap on this motor so i just bay what is best for my motor size!
thanks torben for your help!
Yes. The Fk87 isnt exactly strong in the lower rpms, so the engine needs all the help it can get.

I do not have loads of experience with 200+ hp type 1īs. But what I have seen is that even on a 2387 pushing 235 hp. the 1 7/8" was on the large side. For all out racing, fine. But the streetability was better with a 1 3/4", and it didnt really loose anything on top. It just maxed 200 rpms earlier.

T
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