My $100 dollar Top Mount Manifold Project. RB-->s30

[streeteg]

OK so after plenty of research and some trial an error with a few manifold I have come to the conclusion that there are very limited options without going COMPLETELY custom on a manifold to mount a top mount turbo in an S30 with an RB.

 

Here were the options:

 

1. Stock Manifold, Tapped for external gate

2. stec manifolds

3. Cheap-o ebay manifold

4. 6 Boost

5. Full Race

 

Here were the issues:

1. Stocker tapped---

Backpressure using a log manifold is always an arguement, so I will put it out there, however between the manifold and the actual frame/engine bay does not leave enough clearance for a turbo IMO. You can shoehorn in some turbos, but my choice turbo is the hx35, who's dimensions would be cutting it to close.

Wastegate placement/ exhaust scavenging. The w/g will scavenge gases out of the manifold closest the the cylinders it is mounted. Also again, up for debate, but a factor i considered

 

2- Stec- I have not tested these manifold but in the 240sx and silvia they apparently do very well. Particularly with their beefed steel. They may have issues with their clearance of the wastegate past the strut tower. Not to mention the "good manifold (or good in my opinion) only come in a t4 option.

 

3- ebay Wastegate has to make 180 degree turn to exit. Bad news. Boost creep. Also shitty steel.

 

4- 6boost- Untested

 

5- Full Race- My buddy and I just got done completeying his however when we moched it upit looked to have clearance issues with the strut tower. That and Price. 2200 is just wild for my goals and usage with the car.

 

 

So- I figured the best place to go was cheap- because if I screw it up then I am only out hte 70 bucks I bought the manifold for used. I am using this design.

 

http://cgi.ebay.com/ebaymotors/Nissan-RB20-RB25DET-TURBO-MANIFOLD-TOP-MOUNT-SS321_W0QQcmdZViewItemQQhashZitem3a573923a3QQitemZ250571465635QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

 

I picked one up used locally for 70 bucks.

 

Off with the Wastegate tube. In its place will be a bung for a pyrometer. Great placement in my Opinion.

 

Now we remove the "brace" for clearance on new wastegate placement.

 

Now we cut @ 45 degree angle new tube on the collector, and weld it into place. riiiight about here:

 

The 2 bolt flange will be removed in lieu of a mvs 38mm vband attachment. A solid piece of steel will fit in the cut tube on the bottom and will fit the pyrometer. I will then get the manifold coated, wrapped in thermal wrap, and see what happens.

 

All in all, boost control, and turbo fitment were my goals. IMO I will probably buy another manifold and do the exact same mod so that when this one cracks I have an easy replacement. Car will see drag time but not the sustained heat of much road coarse racing--- at least this year so durability will be taken care of via lack of that wild condition, and a flex pipe right in the DP.

 

Not sure what you guys think, or maybe if you guys have tried it, however its just something I started today out of boredom and it may or may not end up on the car. Not sure what experiences you have had with these style headers but if you had success w/ 6boost or stec or Full race for that matter please dont hesitate to post up I am always trying to learn.

 

Thanks

Eric

[Careless]

pics?

[streeteg]

the pics arent showing up?

[Ricky Ricer]

I can see them and I'm on my work computer.

[Evan Purple240zt]

No pictures for me either.

 

Someone on the RB forums on nico has already basically done this with decent results.

[leftover z]

I can see the pics just fine

[streeteg]

Well when I get it all finished Ill find another host to put the final product on.

[MAG58]

How thick are the tubes? IMO that wastegate pipe looks close to glorified foil.

[sq_creations]

I put a ebay manifold on a car for customer against my advice last summer. I could see the metal stretch as you bolt it on. It lasted almost 2 months. Now he has a real manifold on his car.

[streeteg]

Was it a datsun? What manifold did they use?

[sq_creations]

It was an integra. The manifold looked alot like the one above.

[Racinjitter]

Don't count out LoveFab manifolds, they make them for RB's with or without a/c for fitment in s13/s14 chassis. But they are spendy also.

[streeteg]

I actually did some more research and have ordered an stec manifold this past weekend. 321 steel, and construction that has been proven in some 240sx's so I am going to test it out for fitment in the datsuns

 

Stay tuned

[RB26powered74zcar]

I actually did some more research and have ordered an stec manifold this past weekend. 321 steel, and construction that has been proven in some 240sx's so I am going to test it out for fitment in the datsuns

 

Stay tuned

 

Cool... I have one that I bought awhile back to swap out to single turbo with. I bought a new GT35r to go with it, but have not test fitted the manifold yet.

 

I'd have to pull off my whole hot side to be able to test fit the sTec, so I decided to wait till it warms up a bit.

Please take good pics for everyone!!!

[streeteg]

What manifold are you using now? Are you still running the twin setup that is in your pics?

 

My only concern is wastegate placement and the steering rack. They dont have much of an issue in the s13s/14s so hopefully we will get lucky. Manifold lead time is 4-6 weeks. I bought the new t4 housing atp makes for the 3076R and will be doing some testing with that vs a 35r off of a buddies skyline. This is all for the future though. its just nice to collect the parts in my basement.

 

-E

[RB26powered74zcar]

Yea, the manifold is T4, so I sold my T3 .83 turbine to BigPhil, and now have to come up with a T4 turbine for my GT35r. ATP wants tooo much money just for a turbine (T4 divided) so I'm keeping my eyes peeled for one to pop up.

 

My Stec is a divided T4 manifold. And yes, the w/g pipes look like they will need rearranging, to clear the steering rod.

 

[streeteg]

Im still keeping my fingers crossed on the w/g placement. I hate modding manifolds-- its just a reason for them to crack. I have heard good things about this particular piece though so I will keep you posted on hte progress. The turbo i order has a pretty decent lead time so you might beat me to the punch.

[J Taylor]

I have been using an OBX header from ebay for a couple of years now with no problem. It seems I have one of the first runs though. They have a 2nd version now that is apparently not as good. Other than having to redo the wastegate pipe, fitment is perfect.

Mine looks just like this one but only has a t4 pattern: http://cgi.ebay.com/ebaymotors/Nissan-RB20-RB25DET-OBX-T4-T3-Equal-Length-Manifold_W0QQcmdZViewItemQQhashZitem2558b565fcQQitemZ160402073084QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

[streeteg]

Interesting---I was looking at that one- however I had not heard of anyone using it up until now- and the stec was a twin scroll setup. Also the dual drilled flanged weirded me out- But it is good to hear that it has lasted you that long. The Stec is made out of the same thickness material.

 

Do you have any pics of what you had to do to fit the wastegate?

 

-E

[synthtk]

I picked up a used Greddy T4 manifold off eBay for ~$350, the only thing I had to do (well other than fixing a crack and resurfacing the flanges...) was modify the wastegate pipe, but that was mainly because I put a TiAL 44mm vband on it instead of using a 4 flange 40mm wastegate it was setup for originally, it might have even fit with the wastegate pipe not modified..

 

I have a ForcedPerformance GT3582 HTA w/ 1.04 T4 hot side on it, everything fits great!