Rb25de (supercharged) Project

[r33_racer]

So I got a couple more pictures. Some of an adapter so I can run my standard TPS on the new billet v8 throttle body. The picture wont show the TPS as I left it at work. But its bascially an extended drive that slips over the throttle bodies one and the aluminium adapter plate sits around it so the std TPS can bolt on top and be driven by the new extension. Looks pretty damn good and saved me finding a ford style tps and wiring it in.

Tonight I got a little bit of the intake done. Ran into problems with it at the start. Couldnt run it at the intended width as it was going to leave almost next to no room to run cylinder 2 and 3 primaries out and up. So the way its made now should solve that.

Tomorrow is another day and hopefully I will get the intake done. Well its after 1am, so perhaps today!

[TiTAN]

When you get a chance to run it up on a dyno could you overlay the race car graph on top as a comparison for low down torque? will be interesting to compare it to the 3L.

[r33_racer]

I will do that. Will be very interesting to see the torque and hp differences at various rpm. More so the down low difference. Maybe the superhcarger will turn the 25 in to a 30

[r33_racer]

Easter break was utterly hopeless. Got next to nothing done. But I do hope everyone had a great break!

However, intake is fully tacked together right upto throttle body flange. So a couple of hours of welding and abit of cleaning up and it will be done!

It was quite difficult and as a result very time consuming/frustrating. Just the pipework for this intake to get upto this point now is something silly like 15hrs. Could very well be a 20hr long item by the time its fully done. Oval pipework which reduces in size is a royal PITA! It steps down from 4" to 2.5" in that last stretch to suit the throttle body flange.

Some more good news I should be getting the new 1000cc ID injectors and 2 x 044 pumps delivered tomorrow hoorah!

[Rowdy]

wow... that looks fantastic! completely different from anything else. i wonder if putting the tb so far away will create some lag? as the piping, cooler and plenum will not be pressurised when you put your foot down?

cant wait to see this up and running.

cheers, Rowdy.

[r33_racer]

wow... that looks fantastic! completely different from anything else. i wonder if putting the tb so far away will create some lag? as the piping, cooler and plenum will not be pressurised when you put your foot down?

cant wait to see this up and running.

cheers, Rowdy.

Thanks

Yeh thats very possible. My old man has suggested the same idea and I have mulled it over myself. I guess I will find out when its done.

Initially I was planning on leaving the TB in its standard position. However Sprintex told me I should put it before the supercharger and various books and info ive come across have told me the samething. Hopefully they are right and its in an ideal/optimum spot.

[Mister25t]

Awesome work, really interested in the outcome. Low down power should be wicked.

Your fab work looks very well done, thanks for documenting the process.

I think you could have the throttle after the charger as long as the bypass opens up and stops the outlet pressure from spiking on throttle closure and lets it freewheel when you are at idle or cruising. I'm no expert though. Did they say why the throttle should be in front?

[TuMor]

very interesting read! *subscribed*

[r33_racer]

Yeh I read my supercharger book again and its informed me you need the bypass and throttle setup in that position so at idle and light throttle, where there is no boost the bypass lets air skip past the supercharger or else the supercharger just heats up the air and attached piping/ic unnecessarily which is no good for when you do put your foot down as there is alot of residual heat which shouldnt be there. It did also mention that throttle response is slightly dulled, but apparently its not that bad.

Im not totally positive why you couldnt just leave it in its std spot and then just have the bypass setup so it still does its job properly. But Im not an expert on this either, so I just did what was suggested to me by people who are and hopefully their advice works.

[r33_racer]

Got the intake fully welded, still needs to be cleaned up inside though. Welded in pipe for the bypass valve on intake side and welded bypass valve plate to supercharger outlet. Did some dummy fitting with radiator and shroud to make sure it all fits ok. Everything is looking good so far!

Still got the boost control valve to go in and gotta sikaflex in the afm and then hopefully I will be starting the exhaust! If all goes to plan I should have all my mandrel bends made by the end of the week. Fingers crossed!

That is sort of what it looks like now.

[zebra]

Very impressive.....hurry up and get the thing started...I want to hear it

[r33_racer]

Thanks. Lol I know. Im pretty damn keen to hear it too.

Did abit more tonight. I welded in my boost control valve and then started on my fuel system.

I got the surge tank fabricated with -8 fittings. I cut a mounting plate for it and the pumps also. Then the nights over and that was about 3.5 hrs worth.

Edited April 13, 2010 by r33_racer

[SRX720]

Some excellent work in this thread, i'd put the TB between the the charger and the plenum personally, but from what i have seen the simpler setup is to have it set up as you do, and you certainly have a lot of welding invested in that setup.

what's Nissan's designation letter for a supercharger out of interest?

i'm still trying to work out the geared drive arrangement on that charger, i take it the counter driven screw spins at ~ twice the speed of the driven screw?

[zebra]

I'd definatly stick the the TB before the blower...look at every positive displacement blower setup on a car whether its OEM or aftermarket they all have the TB before the blower.

I dont knwo of any by-pass valve that would flow enough to keep a blower like that happy....if it were a centrifugal blower like a vortech or powerdyne etc than you would run the throttle body like normal as they barely shift any air at low engine speeds

[r33_racer]

Thanks Will! There is a shitload of welding involved in that intake/tb setup. If i were doing it again I would do more research into seeing if I could run it as you say to save the amount of fab work involved in it.

Im not sure on the designation for it, but I think Duncan mentioned it back on the first page.

I think the counter driven screw is 1.5 times the driven screw. Well one shaft has 4 lobes and the other 6 from memory, but will have to check that.

[r33_racer]

RB25DE ®!

[TiTAN]

who registered the RB25DE trade mark?

[r33_racer]

lol stupid thing. RB25DE[ R ]

[SRX720]

yeah sounds about right, i wonder why they run at different speeds, I've never really considered superchargers before but have always wanted to twincharge something.

Looks like the designation is R, so it would be an RB25DER if you believe in renaming engines that never existed

oh yeah, dunno if you have seen this vid before but there is a link to their build, might be useful. they have put the TB after the charger but i would still leave yours where it is. (now i check it someone already posted the link to that build diary)

i can still remember the sound 4AGZEs (supercharged 1.6 litre toyota motors) make, its like a 3 pitch tone, sounds totally awesome, though rumour has it they make that sound when they are out of gear oil, so not the best sound to hear.

Edited April 14, 2010 by SRX720

[r33_racer]

Yeh twincharging would be the way to go. One of the 2.8L jobs to get you to about 800-900hp and then throw a 2000hp turbo of some kind to take over. I can envisage big power with not so terrible amounts of lag. Would just be a nice big painful experience fitting it all in and engineering it so it works nice.

StockyMcstock did it ages ago and I was fortunate enough to go for a spin in it and it was insane. Though it wasnt that exact combination. I think it was a small eatons with a gt40 on a fandangled steampipe manifold he made himself. It is a fancy setup and worked a treat! It was damp or rainy that morning and it was quite loose!

I should make a fancy coil pack cover with the new designation on it....mmmmm Cheers for the idea Will!

Yeh ive seen that video and the whole build thread on the GTR UK forums and on a couple of others they posted it on. It was their build that inspired me to actually look into this in the first place. Abit of research into these superchargers and I got sucked right in!