Seeking Info- Rb20Det Intake & Exhaust Manifolds.

[INDEEP]

So I'm fairly new to the World of Skylines, and the RB engine family. I know they're good though, that's why I'm putting one (RB20DET) into my abstract daily drive (a 1976 Triumph 2500 Mk II Saloon).

The engine is basically in the car (and is currently 100% OEM), but I'm running into a little bit of trouble with the intake and exhaust manifolds (particularly the exhaust manifold) in regards to engine bay space.

Intake wise, I'm interested in these top-only front TB type throttle bodies:

http://cgi.ebay.com/...=item20bbaae484

Does anyone have one fitted? If so, what do you think of it? I've been around cars long enough to know that, "bolts directly" often really means "just bolts up after 7hours of resigning and modifying part".

I'm using a traditional 450x300x65mm intercooler with the outlets at the 'top' of either side (again with limited space), so a front positioned TB type plenum is almost a must-have.

Plazmaman etc are out as I'm on a slim budget, and I'm not about to shell $1000 for a single part for a car that barely owes me $3500 all up. Mock me if you will, but I'm trying to prove a point with this thing, which is, decent performance, and driveability in a unique form, without spending the value of a new family sedan.

The exhaust/turbocharger is where I run into trouble. The turbo is very close to the subframe, so much so that I wouldn't be able to upgrade to even an RB25 turbo without it fouling on something. So I've been emailing all these eBay stores asking for some dimensions from the turbo flange to the cylinder head. It would seem telling them I'm performing a "one-off" conversion doesn't quite sink in, and so far (we're talking 4 replies so far) I've been asked "what body" and told "we would have one to suit that body". No, you don't!

I guess I'm asking for some dimensions if you've got one, and perhaps some pics. Because I really don't know how well they will fit, and I don't fancy my chances of getting a refund if I buy something that ends up being useless...

I'm particularly interested in these (see below) "front mount" models, but I really need to see one installed (and get those few measurements before I go ahead with an order for one).

http://cgi.ebay.com/...sQ5fAccessories

I'd appreciate any help.

http://www.cardomain.com/ride/3924997/1976-triumph-stag

Edited August 10, 2011 by INDEEP

[R31Nismoid]

Can you fit the stock intake on?

Based on the testing Roy did - there was no point upgrading the stock intake unless over at least 280rwkw. Infact upgrading it to quite an expensive brand, hurt response and power. So in effect it went backwards compared to the stock intake so go with that if you can fit it in.

In all honesty that manifold you are looking at is junk. But thats ebay, and that's all you will get for $400

[TiTAN]

the design isnt going to flow much more than the stock one will and being a cheap ebay stainless manifold its going to crack/warp.

you need to accept that the world of ebay parts/suppliers is not one of quality, performance or guaranteed fit.

[INDEEP]

Can you fit the stock intake on?

Based on the testing Roy did - there was no point upgrading the stock intake unless over at least 280rwkw. Infact upgrading it to quite an expensive brand, hurt response and power. So in effect it went backwards compared to the stock intake so go with that if you can fit it in.

The stock intake will fit (exhaust too, but like I said, there's no room for anything but a stock turbo, and it will no doubt blister the paint being so close- something I want to avoid).

My main problem with the intake is the piping for the intercooler. The engine is so tight in the engine bay that the radiator will have to be mounted on the grille side of the support panel (luckily there's a good 300mm between the radiator support and the grille), so there's no room to run the radiator-parallel pipe from the FMIC to the TB like a Skyline does.

So unless anyone out there wants to buy my brand new 'cooler so I can get one with the both the inlet and outlet on the same side, I need to find a way to make it work, and efficiently.

[R31Nismoid]

Dare I speak these words... But why don't you use a SR?

[bubba]

If the stock intake and exhaust manifolds fit then just run with those, if you want a turbo upgrade then get the RB20 turbo highflowed.

Anything else will require someone to fabricate a manifold specific to your car.

Intake wise, you can't get a F/Greddy for RB20. I didn't feel like going for an ebay option so I had a custom one made which after much headache is finished..

[INDEEP]

Dare I speak these words... But why don't you use a SR?

This is the kicker... I avoided the SR because it would've been a relatively easy conversion in contrast (well, not really, the radiator would be the only difference).

The problem is, when you want to do something ridiculously unique, you gotta make sure it's hard enough to achieve that 15 sheep don't follow along behind you.

Bubba, that manifold looks sweet. Cost an arm and a leg?

Edited August 10, 2011 by INDEEP

[GTScotT]

I applaud your efforts and would like to see it running eventually

However I dont think you will get much more space conscious than the stock exhaust manifold in terms of 'off the shelf' fitment..

I have an exhaust guy who does SUPREME work and comes to you (dont need to drive the car to a shop), he could fabricate you a manifold to suit ANY situation (remote location for the turbo if you really want).

I HIGHLY recommend you pick what turbo you want on the car before you get a manifold OR dump pipe fabricated for that matter. Otherwise you will be wasting money doing the job twice when you realise the factory turbo is a piece of crap.

GL!

[bubba]

Bubba, that manifold looks sweet. Cost an arm and a leg?

Nah not really, cutting and welding the GTR plenum ($100) to the RB20 runners (already had) initially cost me $400. Then I had to wait for engine to go back in so I could figure out the water outlet which was the bulk of the headscratching as I wanted to retain the 3 water outlets under the runners. Ended up with a swirl pot that joins the water pipe underneath into the main water outlet and spits it out to the radiator, has fittings for the two temp senders and a bleed at the top because it's now the highest point of the cooling system.

I think all up it cost me about $600 and a carton of beer

[INDEEP]

I applaud your efforts and would like to see it running eventually

I'm hoping it's done before the end of the year. Most of the tricky fabrication is done, or at worst, thoroughly nutted out. You're on the money, I don't see the point in plumbing it all up twice. I'm happy to run with the stock turbo (for now), but I'd like to get the intake side sorted, so I'm not setting up all the pipework twice. I'm really starting to think that my tax cheque should buy me a Plazmaman intake manifold, even though I've been trying to talk myself out of it.

It seems all too aparent that the eBay stuff is crap. I always had reservations about the quality of the eBay stuff, purely because it's so much cheaper, but like I said at the top, I'm new to Skylines, and cheap and nasty doesn't really exist in the World of Chevy BelAirs (my other car). With them, everything's either expensive, or really expensive. Expensive is made off-shore, really expensive comes with "Made in USA" blazened across it.

[INDEEP]

Nah not really, cutting and welding the GTR plenum ($100) to the RB20 runners (already had) initially cost me $400. Then I had to wait for engine to go back in so I could figure out the water outlet which was the bulk of the headscratching as I wanted to retain the 3 water outlets under the runners. Ended up with a swirl pot that joins the water pipe underneath into the main water outlet and spits it out to the radiator, has fittings for the two temp senders and a bleed at the top because it's now the highest point of the cooling system.

I think all up it cost me about $600 and a carton of beer

Hmmm, I've got $35, 3 cartons of Cartlon Dry and a rubber chicken. What can you organise?

With my new found backyard engineering prowess, I considered cutting and shutting (something), but my limited spare time (2 jobs) doesn't allow for too many hours of looking outside the square. Especially when I'm just probably just being a bitch about the most effective way to run the intercooler piping...

Yep, I'm THAT guy when it comes to building stuff.

So, I've established that Chinese eBay parts are shit, and that the stock RB20 turbo is paper mache`. This is actually helping. Thanks gents.

[INDEEP]

My next stupid question. Are there any major problems (ie: a significant drop in boost) by installing a bigger plenum on a car with a stock turbo and running stock boost?

Edited August 11, 2011 by INDEEP

[bubba]

Shorter runners means less low down torque (mine is on a 3L so I'm not worried), we have proven a standard RB20 plenum and throttlebody can make 365rwkw so unless you have plenty of coin to splash about and lots of time to R&D I wouldn't bother.

A bigger plenum chamber will probably give a bit of lag when opening the throttle as there is a lot more volume to fill.

You should also be able to get an RB20 turbo highflowed enough to make a solid 240-260rwkw yet still be in the small factory packaging and fit on the factory exhaust manifold.

If the standard engine setup fits, I would be inclined to keep it that way to get everything running (no point in introducing more possible failure/headache points) and then look at what can be optimised.

[INDEEP]

If the standard engine setup fits, I would be inclined to keep it that way to get everything running (no point in introducing more possible failure/headache points) and then look at what can be optimised.

Exactly. I don't want (or need) the headache of tuning/sorting a modified engine that is also housed in completely foreign surroundings.

The intake question purely exists as I'm really doubtful as to how well I can plumb up the 'cooler "traditionally" with the limited space I have in front of the engine with the style of intercooler I have (see image):

.

I think I'm just going to have to see what I can do with it first. Seems to be quite a few guys singing the praises of the stock plenum, so making it work (even if I have to change the intercooler) makes more sense than throwing coin at an aftermarket version that is only working to a small percentage of it's potential.

Looks like most RB20's run 2.5" piping instead of 3"? And I'm assuming most mock theirs up with white PVC or something beforehand? (I refer to those who can't buy a kit).

[GTSBoy]

You likely have more options for running the pipework than you think. You may be able to take the turbo outlet pipe and direct it down next to the motor, across the front of the motor just behind the bottom steelwork under the radiator opening, out and around to the intercooler, then bring the cold air back on the passenger side and straight up to the standard inlet manifold. Note, that I'm not sure how retarded the Triumph engine bay design is or how crowded it is once you've jammed an Rb20 in there. If there's not room for the low route, then you could look at passing the hot pipe across to the other side going above the fan shroud (immediately in front of the timing cover. There has to be room to fit a 2.5" pipe across there. A lot of people pass the cold pipe back across there in Skylines when they put a cooler like yours in. Either way, the pipe run is a bit longer than ideal, but a lot better than dropping a huge amount of coin on a plenum that won't do anything for you except clean up the pipework.

Also, on the turbo side.....The RB25 turbo is essentially the same size (physically) as the RB20 one. So you should have an upgrade path to there, if you can fit the 20 in in the first place. But even so, you can make ~170rwkW on the RB20 turbo at ~14 psi with a decent cooler and exhaust, on standard AFM, injectors and everything else. You will need a retune on the ECU (using a Nistune board) in order to get it up to that sort of power, otherwise it will be down maybe 15kW. Regardless, this is a healthy amount of power and torque for a car that is made from laquered cardboard with a structural paint laminate (my dad has ownded Triumphs, so I know how they're built). It's not a particularly heavy car and it will probably go quite well just with a boosted, basically standard 20 anyway.

cheers

[INDEEP]

You likely have more options for running the pipework than you think.

I wouldn't say space is plentiful...

Edited August 11, 2011 by INDEEP

[GTSBoy]

Yeah, so is there room under the front pulley?

[INDEEP]

Yeah, so is there room under the front pulley?

Yep... So you're talking something like this awesome piece of art below?

Green being the air filter (der!), Red intercooler to TB, and Orange turbo to intercooler.

Edited August 11, 2011 by INDEEP

[bubba]

Yep... So you're talking something like this awesome piece of art below?

Green being the air filter (der!), Red intercooler to TB, and Orange turbo to intercooler.

Indeed, piping might work out easier if you swap the pipes going to the cooler though.. turbo hot pipe to other side and cooler cold pipe straight to crossover pipe.

[GTSBoy]

Yep... So you're talking something like this awesome piece of art below?

Green being the air filter (der!), Red intercooler to TB, and Orange turbo to intercooler.

Yes but no. As bubba said, hot pipe out of turbo down to the bottom, across other side into cooler. Cold pipe out of passenger side of cooler and straight over to the standard crossover pipe.

Indeed, piping might work out easier if you swap the pipes going to the cooler though.. turbo hot pipe to other side and cooler cold pipe straight to crossover pipe.