Trying to squeeze power out of an N/A SD33

[ipatrol26]

Hello guys,

I am trying to increase some power out of my N/A SD33 and I would like to hear from the experts first.

- I am thinking on doing a new 3" exhaust pipe
- switching to an electric fan instead of a mechanical one
- adding a custom DIY snorkel with the original safari head using a 3" stainless steel pipe.
- adding an after market turbo (can it be added and will it work just perfect??)
- and last but not least (optional) can I lightened the main pulley because the original as some of you might know its heavy as &/(&&% so I am trying to builted out of aluminum or something.

Please I would like to hear your thoughts, doubts, pro´s and con´s.

thank you.

[YNOT]

3" exhaust is a bit big for a naturally aspirated 3.3lt motor, 2 1/4 or 2 1/2 would be better and combined with extractors/headers would result in about 10% power increase. Have a read of this thread which explains the effects of different exhaust sizes; http://www.nissanpatrol.com.au/forums/showthread.php?5112-Exhaust-Back-Pressure-and-Flow-Velocity

Switching to an electric fan will unlock a few more horsepower but nothing dramatic.

Snorkel will help, use mandrel bends for best flow. I'm not sure how restrictive the air filter is, a bigger Donaldson type filter may help.

While you can add a turbo to a naturally aspirated SD33 it would be better to fit a complete factory turbo SD33T engine which have stronger internals.

Be careful with lightening pulleys and flywheels as it may result in a reduction in torque output. Be especially careful with flywheels, the centrifugal force at high revs can cause flywheels to explode if it hasn't been done right.

Tony

[lachiek]

Hey mate, having had one of these for a few years in an MQ SWB I know they are a great engine but having played around with a few options I reckon there is only one thing that will make a NOTICEABLE difference to how the SD33 pulls. Point it downhill.

You could spend a lot of money for a very little improvement - mine had a snorkel on it and was well tuned but NA otherwise. It went everywhere and was very reliable so I just lived with pulling away slowly and driving up highway hills at 80 kph. I thought about a bigger exhaust and drove another MQ with a 2 1/2 in exhaust. Sounded better than mine but couldn't feel any difference in power.

Have fun with it, Lachie

[Finly Owner]

Noi\t that I think it's noticeable, but removing the Second air filter and relying only on the primary filter may give you a tiny percentage. Running smaller wheels gives you better take off obviously.


Tim

[ipatrol26]

I totaly agree with you guys, after thinking over the option to lightened the pulley its kind of dum but it was just something I though about. Now in regards to the exhaust pipe I will defenetly go with "2 1/2 but I was thinking on making my own headers out of the same lenght pipe; what you think of that????

Other things I am considering doing are:

-bigger donaldson air filter fitted with the snorkel using "3 pipe.
-Completely isolate the exhaust heat from the engine compartment and somehow get as much fresh air as possible inside the compartment through some type of vent or something, that way the engine can perfom better and wont suffer from overheating.
- Cleanning the oil colling compartment and cooling device ( I know how to do it, but any advise)
- Switching to an electric fan instead (Any advices, Pros and Cons). Will it perform better or will do the same.

I know I can't ask for much power out of the N/A SD33 but as long as I can get at least 10 more I am good.

[Silver]

take it easy, sit back and enjoy the ride, I say.

[the ferret]

Yeah, all said 'n done, the sd33 is a plodder, great un breakable motor, but still a plodder, if ya want more grunt, fit an sd33t and a 5 spd.

You can turbo it, but the rings and other things within the motor are not set up for the extra HP, it's only gunna led to heart break.
V8 it!! 5.7 litre whoosh.................
cheers , the Ferret

[MQ MAD]

Leave the factory clutch type fan on it
Theres bugger all power advantage goin to electric fans
Its not the old style fixed fan power robber from last century
They are IF working fine a great system that actually are better than electric fans

Turn the fuel pump up a touch , run a set of extractors (yes they are around for the SD33 n/a s)
Run bit bigger exhaust
Thatll do

Failing that drop a SD33T in it , up the boost up the fuel and all done