Rb27/ Rb28 Vs Staying Rb26

[XGTRX]

Depends on what the head needs in the first place to get it up to par. It may not be that much more to get significantly better flow if you have a parts list anyway.

[Trex]

Oh and I wouldn't put a rb30 in because I like to close my bonnet

luke has a way around this.

[mr skidz]

I don't doubt the displacement argument but my engine is 2629cc at 87x73.7mm.. If I was going all out with a new N1 bock and stroker is 2738cc at 86

5x77.7mm thats 109cc difference for 7+ grand extra, you'd be nuts to take a virgin block straight to 87mm (assuming for a 2.6 refesh my crank and rods are fine, just new pistons) I would have though improving your VE% by 3 or 4 percent on the 87mm 2.6 with good head work would yeild similar results? If you're going all out, sure do both. But on an assembled 2.6 engine you'd see similar gains with just doing the head work. If I wanted solid grunt I'd be looking at over 3L for sure.

not sure if there still available but TOMEI had a 87.5 mm kit too which brought you out to full 2.8 which is an option.

besides nobody says you have to use a N1 block.

[Nismo 3.2ish]

jeeezz you and head jobs - whats with that

He really really really likes them, and even his dog is jealous

[Stixbnr32]

In direct comp from my non built 26 to my built 26 my I gained power 300rpm earlier due to less rotating weight.

So the built 26 revs better and is a all round monster compared to when it not built.

and I didnt know that strokers didnt last as long. But I have heard of multiple built 26's going for 10 years (100,000km) before their standard rods failed (had tomei bolts and pistons).

I would be happy to get 10 years out of my engine.

[jangles]

price difference from my 2.6 to 2.8 is sweet FA!

1000 - 1500max

money well spent imo.

why spend money cleaning up the old crank which was in good nic + balancing etc, I now have a new 2.8 one.

I prefer the throaty note also.

You would of still got the 2.8 balanced though?

[mr skidz]

You would of still got the 2.8 balanced though?

yeah balanced it already

[mr skidz]

if I was to keep it 2.6 I'd go nitto and spin it to the moon.

[XGTRX]

In direct comp from my non built 26 to my built 26 my I gained power 300rpm earlier due to less rotating weight.

So the built 26 revs better and is a all round monster compared to when it not built.

Together with being able to put a ton more boost into it.

No comparison to a stocker.

[GTR_JOEY]

Defiantly need to balance brand new stroker cranks, never assume that it is good to go out of the box

[XGTRX]

if I was to keep it 2.6 I'd go nitto and spin it to the moon.

I remember reading an article on a Fred Gibson interview and its interesting that he said that the RBs have an issue passed 8300 rpm. From memory he said due to the long crank, it didn't matter what they did, there was an inherent harmonics issue that would have detrimental effects on the bottom end if the rpm was kept above this point.

Don't know if he was using standard cranks or not, but I wonder if the issues still exist today with after market kits?

[mr skidz]

was just highlighting that there's usually machining costs to clean up a 2.6 crank, should have left the balance costs out was obviously tired. night shifts will do that

[33SOM]

That crank was listed last week as a doorstop and obviously didn't sell.

I'm the seller of that crank.... I didn't have the heart to throw it away..

[r32-25t]

Together with being able to put a ton more boost into it.

No comparison to a stocker.

you can jam a shit load of boost into a stock engine. simon in wa is making over 500kw at the wheels on standard internals, is he doing it with 1 bar of boost? I don't think so

[Stixbnr32]

I remember reading an article on a Fred Gibson interview and its interesting that he said that the RBs have an issue passed 8300 rpm. From memory he said due to the long crank, it didn't matter what they did, there was an inherent harmonics issue that would have detrimental effects on the bottom end if the rpm was kept above this point.

Don't know if he was using standard cranks or not, but I wonder if the issues still exist today with after market kits?

Isnt that why RIPS and the like brace the block or fill it with something to stop the harmonic vibrations when things are taken above 8300rpm?

Suppose racing around a track when your RPM is that high for hours on end then I can understand the issue.

Not like a drag race where its 7-11 seconds worth depending on how deep your pockets go.

[GTRPSI]

Ripps specialize in RB30's.

The RB30 is known for that harmonics issue and ive discussed it with a few well known RB30 builders, the consensus is that its at over 8000 rpm at various points of the rpm scale at varying levels.

For example a engine may have a large one at 8200, a little one at 8500, another large one at 8800, a small one at 8950 etc.....

Point being is if you rev through it, its not a issue as your not sitting on it, you transition through it, you just dont want to be holding it at a particular high rpm where its at as it will want to tear its self apart.

[XGTRX]

So do the after market cranks make a difference

[SimonR32]

1 - Tomei stroker = $5,200 on nengun ATM. That includes crank, rods, rod bolts, rings and pistons.

2 - Machining and assembly, lets call that $3,000

3 - Head gasket = $300

4 - Water pump and oil pump = $1700 for both

5 - Head and cams. That could range from a service to a full blown $10,000 effort. For the sake of it lets go with $2,500.

6 - New timing belt = $150

7 - Bearings = $300

The rest of the stuff like sump baffles, turbo's doesnt really matter.

Items 2-7 you need regardless of what size engine you go with.

Now, Just say you have turned a bearing in your 26, crank is toast.

New crank (looked up a price on Ebay) = $1724

Pistons. Choose your poison. Lets go with CP = $1155

Rods. Say a manley H beam = $1280

Total $4159 for the rotating assembly. As opposed to $5,200 for a tomei stroker.

$13150 for a stroker

$12,109 for a 2.6 assuming new crank needed with the same above mentioned parts.

I havent inlcuded shipping in any of this. Either way you'd be paying it regardless.

These are VERY rough figures. I'm not going to sit here all night looking for the cheapest part or your brothers cousin can do a special price.

By the time you factor in injectors, clutch, fuel pumps, ECU, tune cost, exhaust, dumps, turbo's, intercooler, wheels, brakes, tyres and alllll te rest of the gear you need to "complete" a car, the difference is insignificant.

*Shudders* at cost because I'm tight. I also remember my OEM RB26 crank was under $1000 but that was trade price about 10 years ago so things may have changed.

Being around a lot of GTR's on the street and track over the last 12 or so years I can say this, a RB26 with a good set up will be better than and average set up RB28. A well set up RB28 is always going to be better than a RB26 (although they do tend to turn over a little sooner). In terms of cost, if you are building the motor it's probably worth the extra cash but if you have a healthy stock motor I'd be saving the $13k and getting the right modifications to make a well set up RB26.

Joey's RB26 is even more responsive than mine (by the dyno graph) and still makes awesome power. My RB26 has a little more top end potential but still has more power than you would need anywhere, check the footage below. This is a tight low speed track in a which stoker GTR owners would say would be a nightmare in a reasonable hp RB26, but even on sticky soft compound R-comps I have enough response to get boost anywhere I need it and enough power/torque to spin all 4 tyres through any corners at will.

[GTR_JOEY]

Correction... "Was more responsive"

[Stixbnr32]

Looks like a tricky track. Good stuff.

Love the screamer