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Hi Guys

just got back the results of the flow tests between the rb20 standard manifold and the hks cast manifold will mark these 1 to six front to back

standard HKS cast

1. 159.7 170.7

2. 162.4 166.6

3. 160.7 178.7

4. 150.6 183.6

5. 149.9 182.2

6. 173.3 184.7

As you can see all flow pretty well and a marked inprovement over standard but you'll have to draw your own conclusions if the flow improvement is what your after for the cost although afe did state the these are very well made the casting quality was some of the best his seen and flow extremely well for a cast manifold a worthwile investment over standard and he was kinda wondering why they stoped making them . One other thing he said to me was not to tell anyone you have one as he said you'd probably surprise some people with the way the car goes even in standard form to say the least i think it impressed him and that statment coming from someone who deals with these sorts of things daily makes for an impressive statement

Cheers Peter

So who can tell me the internal diameters of the Rb20DE, RB20DET, RB25DE, RB25DET and VG45 throttle bodies?

I figure the Mitsu boys love boring out their throttle bodies for a few extra kws...

And has anyone looked at the alignment of inlet manifold to the head? I figure if the extrude honing isnt too expensive then i will get the inlet manifold flowed, match port it to the head, throw a bigger throttle body on it and see how it goes....

I looked at the inlet manifold porting to the head when i fitted my motor up together. Basically there was sfa difference. I just took out the 1 or 2 mm here and there that was the difference. I was suprised how well the std nissan stuff was matched Roy. Using the gasket as a template and a rotary tool it took only like a few mins to get it spot on...

Extrude honing the inlet would be good as well as the exhaust manifold. As far as i know the tb is about 2.5" (same as ic piping/afm ~80mm) and the VH45 is about 90mm (same as the afm)

Edited by Bl4cK32

Several years ago (there is thread on it), we flow bench tested a standard RB20 cylinder head, inlet manifold plenum and throttle body up to airflow sufficient to make 500 bhp. It showed no improvement when we removed the throttle body completely. So fitting a larger diameter throttle body is a waste of time and money until at least 300 rwkw is reached. It maybe even more than that, we stopped testing at 500 bhp.

:) cheers :D

Funny you say, the new baby is shooting for 300-330rwkws, so whilst its all apart may take the time for a small improvement here and there

i take it your not doin that on std internals? I was thinking of trying a hks 2835 pro or hks gt-rs and see what sort of number i can pull with a low mount

hopefully soon we'll see how a HKS Fcon V Pro will perform on a RB20 minus AFM...

already seen. performs well, thats IF you can find someone to tune it. atm i'm waiting on a tuner over here in SA that says he's trying to develop some software for it. other than that its only BD4s that can tune them AFAIK.

as soon as i can get it tuned the turbo will be downsized.

KKK-K27@12psi

post-1089-1138344910.jpg

already seen. performs well, thats IF you can find someone to tune it. atm i'm waiting on a tuner over here in SA that says he's trying to develop some software for it. other than that its only BD4s that can tune them AFAIK.

as soon as i can get it tuned the turbo will be downsized.

KKK-K27@12psi

bd4's is the plan

hope the dont shut down! lol

fwiw hks gt3037 = gt30r.

i cant wait to get my engine back together, with proper compression (175psi vs 140psi) the turbo should come on harder and faster with better response.

least i hope it does.

Without a doubt it'll be alot faster.

You can get an 044 to fit internal - I've got 1 in my '33.

Bit more stuffing around but possible.

so i can get the 044 to be an intank pump? would it be just the same as installing the 019? the 019 was a fairly long pump...im just asking as everywhere ive researched everyone keeps saying its an external pump...so im just clarifying

thanks

chris

I have a q45 trotthle body right here. Its 85 mm on the inlet side and 83mm at the valve side.

Was planning to use it on my rb20det after the head is flowed and a custom manifold is mounted, but maybe its a bit to big. Maybe trade it for a rb25 body orso.

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