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Need To Know Tomei Diameter?

NisGTR

By NisGTR,
in Engines & Forced Induction

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Moodles2 Grand Master

Moodles2

Posted
Posted

The old Tomei are 76.3mm (not sure if outer or inner, inner will be 70mm minimum), the new Expreme ones are 73.xmm (again don't know if that is outer or inner, again inner will be 70mm minimum).

If xforce copied HKS' dump pipe design, you can guess their front-pipe (y-pipe) might be a HKS copied design (the HKS front pipe is 2x 60mm into 1x 80mm)

Beer Baron Grand Master

Beer Baron

Posted
Posted

yeah the Tomei dumps are about 75mm ID outlet. the best match for them is the current model HKS stainless front pipes which are 76MM ID as well into single 85 or 90mm ID. they are much better than the old twin 60mm HKS front pipes which everyone copied and the new ones use better flanges, better pipe and the pipe is welded to the flanges on the inside of the pipe which creates a nice smooth almost bell mouth type effect. not cheap, but they are qualiy.

NisGTR Collaborator

NisGTR

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Posted
yeah the Tomei dumps are about 75mm ID outlet. the best match for them is the current model HKS stainless front pipes which are 76MM ID as well into single 85 or 90mm ID. they are much better than the old twin 60mm HKS front pipes which everyone copied and the new ones use better flanges, better pipe and the pipe is welded to the flanges on the inside of the pipe which creates a nice smooth almost bell mouth type effect. not cheap, but they are qualiy.

when you say 75mm is that the new tomei ones or the old ones?

Beer Baron Grand Master

Beer Baron

Posted
Posted

which ones is new? the one on the right? shame they are smaller now. I was talking about the ones on the left as being approx 75mm ID.

as fas as I've been able to find the only common off the shelf front pipes that are that large in the primaries are those HKS ones. They are very, very nice. I think they are about $800 delivered or so from japan. I reckon they are worth it thouh, it's a shame to get nice large dumps only to bolt twin 60mm front pipes onto them.

Beer Baron Grand Master

Beer Baron

Posted
Posted

yeah it's possible. they are without question the nicest fron pipes i've seen. the next nicest were the nismo ones but they are twin 60mm. I had the nismo ones and upgraded to the HKS.

hmm, now that the nice big tomei dumps are discontinued I'll have to hang onto the ones I have. :P I have a feeling part of the reason for the new ones is ease and cost of manufacture. there is something nice about the old welded ones. they look more like artwork than car parts.

Beer Baron Grand Master

Beer Baron

Posted
Posted

yeah bummer about that. I still kind of prefer the old ones. :(

the manifolds use the same casting for the pipes and then welded together. this helps them resist cracking as the pipes have not been bent or section welded to form the bends, they have been cast that way. they are very nice too.

picture006zr0.jpg

you can just see the inside of the welds inside the collector.

picture008qe3.jpg

so nicely made.

picture012so8.jpg

here's some pics of my tomei dumps. i've now used them on 2 of my GTRs and had a few sets for mates etc too. still have one set new in their box at home for spares!

picture015ah9.jpg

picture008oy1.jpg

picture005lv4.jpg

picture018pr1.jpg

picture017kp5.jpg

I would say the main reason of the move to the new style would be ease of fitment (with smaller pipe), ease of casting, lower cost to produce and most importantly consistency in manufacture. since having a few sets of the old style ones I did notice some were just a tiny bit better than others. obviously made by different people/different day etc. but still within an acceptable range.

I sold that set above for about $600. how much did you guys pay for the new ones?

Beer Baron Grand Master

Beer Baron

Posted
Posted

well I've never cracked the old ones, nor heard of them cracking. but certainly the new ones would be even less prone to crack. any time you have welded pipe that is subject to wildly varying temps (from 0-800+ degrees) you have the possibility of cracking as the pipes heat and cool... expand and contract. but it was never a problem as far as my experience with them goes.

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