heidihi

ok i searched and i read mixed reviews.. some say they were good, and some say they suck! ok i understand this will happen regardless of the product. but i also read some say these manifolds need extra work to fit right..

now thats all fine and dandy but what extra work are you talking about? i spent about an hour reading through old threads and im still at step one..

are these ok manifolds to use for nothing major? im shooting for high 300hp at the wheels using a 60-1 turbo.. i however dont have much fabrication skills or welding skills so if this manifold wont fit or if it needs something im pretty much at the mercy of a machine shop here.. so someone be up front and say are these decent manifolds and if there not what are the true problem with them and what needs to be done to correct the issue with them?

thanks in advance..

arghx

iTrader: (3)

there's no reason to get an OBX manifold when you can get a used, divided Greddy cast manifold for like $300 or something, and there's no way that ****'s going to break on you.

heidihi

yes but still it doesnt answer what i asked man.

skir2222

I believe I have one of these manifolds, ran a t04r on it for a year and a half and now I am running a R85 making over 400hp. No problems so far with the manifold.

flyboyjuge

I used one to try to stay within budget...it was a big mistake. they are very thin and a good day at the track will for sure crack it. very bad quality. save yourself time and money in the long run and get better quality. im not sure if they still make the hks cast manifold but its a good one.

heidihi

see already im getting a mixed review.. scares me from buying one.. but then again i have no ambition to go to a track, just leasure driving with every now and then hopping on the gas!

Smitter

I have one of these manifolds. it has been holding up great for about 6000 miles.
i currently have it off the car for an engine rebuild and there are no cracks or signs of fatigue. it stanless so i would assume it is lighter then any cast manifold and would not retain as much heat aswell. keep in mind u could buy 3 obx manifolds for the same price as an hks or greddy one if need be and those arent prone from cracking either. any cracks can be re-welded on any manifold u decide to go with

i am running a 60-1 compressor with a .84 hotside. to give the manifold a little more clearance from the LIM i doubled up the gaskets on the exhaust ports and again doubled up the gaskets between the manifold and turbo. No fabrication required.
here's a pic of the turbo location mounted on the obx, i could take some pics of the manifold too, since its off the car

heidihi

smitty and there were no fitment issues anywhere, or fabrication you needed to do or anything?

Smitter

^^ No fabrication needed @ all, bolts right up, i just double up the gaskets to give the turbo an extra bit of spacing from the LIM

Rocking Rotary

iTrader: (14)

How do you not want to fab stuff when you are going to peice together a turbo kit? You do know you will need to fad up IC pipe and exhaust and wastegate dump tube. Along with all your oil and coolant lines.
Those things suck they are not going to hold up. Buy a good manifold and be done with it. If you dont have the money save it or you will end up spending it down the road.

Viking War Hammer

iTrader: (8)

just buy one from A-Spec

Smitter

Buy whatever u want man, but i have used this manifold and am still using it currently and it works. people on here are always gonna knock something that is not considered a high end product. They do this without even having personally used one and just want to conform, i myself would normally fall into this category aswell.

I have a friend with an a-spec manifold and its not that great, even to look @ its big and bulky and weighs a tonne. He also uses the same turbo as i and experiences quite a bit more lag, mind u he has a fmic as opposed to a smic as i have.

The obx manifold was supplied to me By Adam Heyman of Rx7 Specialties here in Canada. he is a pretty renowned Canadian builder and supplies 20b kits and does rebuilds for many people on this forum. I was sceptical about it at first (mainly due to peoples influences on this forum), but needed a manifold that allowed the turbo to sit back closer to the firewall due to my smic.

Dudemaaanownsanrx7

iTrader: (23)

I'm also using the OBX manifold on a turbo setup i pieced together. I'm pushing around 400hp, i've seen the whole manifold glowing red after some long hard runs. i have no cracks, sealing issues etc, even the gaskets they sent seem to be holding up fine. I was in the same boat as you reading all the mixed reviews, but just said fukit and gave it a go. Fitment was great. I did no reinforcing to it, just stuck it on there. Maybe quality control is an issue? Maybe its hit or miss, but mine seems fine.

Sesshoumaru

iTrader: (1)

I did a FC for another guy with an OBX manifold and there were no problems. I think the taps on the t4 flange were not lined but no fab required.

I run a HKS cast on my FD but have a OBX Manifold too i'm not using. Seems to be same as the FC counter part in quality.

I think they might have changed standards/materials/welders.

warick101

I bought a couple of these just for comparison when I found them dirt cheap. The OBX style with the internal squared off T4 flange was the best. Another I had was the type you see with the "ported" flange. Both had good welds and seemed of good construction, although the ported version had a lot of welding splatter inside that would have needed cleaning, it also seemed to have thinner metal and the engine flange didn't match up on the bolts well. I don't know how either would fair under heat stress, but the OBX was surprisingly good and well worth the price IMO. If Adam at RX7 Specialties gives them a thumbs up then they are probably good. If you are just going for a street application then I'd say go for it. For any type of racing or competition then the peace of mind of a high price manifold is well worth it and would save you money in the long run. Atleast if a manifold made from a well established company cracks you'd be able to get a hold of someone at the company and yell at them. One thing, if you are planning on building your own turbo kit and can't weld, then just buy one pre-made. By the time all is said and done, you'll prolly find it's cheaper and you'll have a lot fewer headaches by buying a kit up-front.

Dudemaaanownsanrx7

iTrader: (23)

i agree with the warick101, if you can't fab up parts and weld, it's almost guaranteed to cost more piecing it together. At first look its like eh its just a turbo, some pipes and fittings, but the cost goes up quick for all the little stuff. I came out ahead with by mine by doing all the welding and making the DP etc. Even learned how to weld aluminum which if i hadnt was going to cost me another 100 just to get a couple intercooler joints welded. and Even though i bought the ss pipe for the DP and welded it together myself it still cost 100 + just for materials. To get one made somewhere else will prob cost like 300 or more. So yeah if you can make alot of the parts, go for it. Otherwise i hope the fabricators there owe you some favors lol.

janrx7

an obx manifold costs $165 while a hks cast costs 370 and a stainless steel can go up to 700 dollars. i plan to buy the obx and worst case scenerio it breaks and you weld it or buy another. my goal is 400whp and apparently it holds on fine a that level

flyboyjuge

Everybody has good points on here. The manifold could honestly work perfect and you never have issues with it. To me peace of mind meant a lot when I had my FD. I would say if you arent going to the track, then you probably dont care too much about the extra weight of a cast manifold. I would just get an HKS cast manifold and be G2G. But its your car and your decision.

janrx7

the hks cast manifold produces more heat under the hood versus an obx stainless steel manifold. does this excess heat affects performance? can the manifold be wrap in heat aislant?

the hks cast manifold has a different design verus the stainless steel obx, the obx manifold is tubular, does this affect performance? i think that the cast iron design affects, air flow and performance, is this true?

classicauto

iTrader: (3)

How can one piece of metal "produce more heat" vs. another piece of metal if they're both being heated by the same EGT's?

Smitter

"retain" should maybe be substituted in place of "produce" in janrx7s post

classicauto

iTrader: (3)

Still doesn't make sense though, because he's saying "produces more heat under the hood". If the cast retained MORE heat, then that would indicate less was being expelled into the engien bay.

Either way I'm just nit-picking that either one is going to be fuckign hot regadless of what its made out of. Only way to reduce either is with coatings, wraps or both,.

janrx7

yeah but i heard that the cast manifold retains or produces more heat and this causes higher temps under the hood. this can't be good.

Smitter

i would have to agree, if cast retains heat more then stainless, egts could possibly take longer to comedown after wot runs and engine bay temperatures would also be higher and take longer to cool down when the car is parked. logically speaking of course

A vented hood is a definite asset with any setup

classicauto

iTrader: (3)

Just for what its worth. On my FC I formerly used a greddy cast manifold the tried tested true ol' desgin. EGT's (at final tune pre Haltech brainfarts) were 1600ish F WOT with AI. Idle I'm not sure since my gauge bottoms out at 1000F, but it would always bottom out after 2-3 seconds idling.

Manifold was wrapped with 2 layers of DEI exhaust wrap. You can touch it after hard driving.

Stainless tubular A-spec manifold. Same tune conditions (as close as you can get after switching is...) same EGT's, wrapped with 2 layers of DEI. You can touch it after hard driving and EGT's cool down exactly the same as before.

Granted, the probes are measuring the temperature of the center primary on each runner - not embedded in the material - but there's absolutely no difference I can tell with data back to back with regards to "reatining heat to pollute engine bay air"

Both are hot as **** (under the wrap) and will heat the engine bay air up regardless if they're not wrapped or coated. The difference of retention between the two materials is moot since there are so many other aspects about manifold choice that have greater effect on ov erall performance such as type (divided vs. non) runner length, wastegate placement (or options for that matter) that to base a choice on which one will stay warmer longer seems pointless after having the two back to back.