rb30neo Ultimate street response

[AngryRB]

Just interested on what people beleive is the best setup for street response, im not talking top end but the best torque and part throttle at legal speed limits..

My setup so far is an RB30 neo with 260 poncams and GT3076 0.83 external 44mm on E85.. making 345kw on 16psi with 230kw at 4000rpm...

My goal was real street fun without lag and not needing to smash the limiter..

Current performance is that she pulls hard from 3500rpm and open wheels hard... but id like to bring this down and don't mind taking from the top to give to the bottom/mid so thinking along the lines of a 0.63rear and 3.7 diff gears but not sure if will give the best results or cause problems.. i quite liked the stock VL turbo type torque delivery and want similar but obviously 300kw plus still.

[Dale FZ1]

3.4 stroker will give more torque at lower rpm.

Going down a size in turbine A/R will be counter productive especially with the 3.0 bottom end.

Can't see the sense in gearing it up with 3.7 diff.  A 4.1 will allow it to turn more rpm for a given road speed.  And give better response.

Stock VLT was gutless off boost, came on with a rush, and then done/gone at around 5-5200.  Brilliant in 1986 but that was a while ago now.

 

[AngryRB]

My daily driving especially in traffic harly sees an opportunity to hit over 5k and when i hit the throttle in low gears it flys through from 2-3krpm so quick that it barely boosts.. ??

If i let it rip to 4k then yes it hauls but seems like it shouldnt be needed.. or do you think i should treat it like a high revving thing and let it rev?

Edited June 1, 2018 by AngryRB

[KiwiRS4T]

I put an GT3540 on my RB30 with a .63 a/r turbine.  It accelerated well from lower revs but made only 314AWKW (although would have done more with E85 and more development - see torque chart below - but I concluded that the vehicle wasn't suited to traffic light drags. Yes if I revved hard and booted it I could leave that Honda Civic for dead but the amount of drama required seemed too much. My automatic Maxima 3.5 with only 200kw seems much more suited for everyday traffic.

[sneakey pete]

EFR probably

[GTSBoy]

Super charger.

 

/thread.

[AngryRB]

Nah no supercharger shit going to happen haha..

Is strange position here, hmm, i have a stock turbo r33 also andni drove it last week and its do crap in comparison.. but i am really after some real early spool and pull into seat business at like 2500-3000rpm hence 0.63 rear and 3.7 thoughts.. if you guys lived near me be good to have opinion on what to do to obtain ultimate result.. im not complaining at all just after more i guess, i experienced a VL turbo manual that pulled hard from 1200rpm in second before that would wipe mine away easy so with that in mind 

.. 

Edited June 1, 2018 by AngryRB

[discopotato03]

Rather than changing turbine housings I'd give the standard cams another go . Stao once told me that he never liked Poncams and found they lost down low and increased turbo lag and didn't do that much up high . 

 

[AngryRB]

1 hour ago, KiwiRS4T said:

I put an GT3540 on my RB30 with a .63 a/r turbine.  It accelerated well from lower revs but made only 314AWKW (although would have done more with E85 and more development - see torque chart below - but I concluded that the vehicle wasn't suited to traffic light drags. Yes if I revved hard and booted it I could leave that Honda Civic for dead but the amount of drama required seemed too much. My automatic Maxima 3.5 with only 200kw seems much more suited for everyday traffic.

Your graph is very similar to mine.. so this is like where i want improve from..

[AngryRB]

Can i improve this, like pull the graph back 1000rpm? I think thats  what im asking, i want it all sooner , redline is like 7200rpm no boost contoller 335kw on 16psi, 345kw is boost conter on 17.5ish psi 

Edited June 1, 2018 by AngryRB

[AngryRB]

2 hours ago, Dale FZ1 said:

3.4 stroker will give more torque at lower rpm.

Going down a size in turbine A/R will be counter productive especially with the 3.0 bottom end.

Can't see the sense in gearing it up with 3.7 diff.  A 4.1 will allow it to turn more rpm for a given road speed.  And give better response.

Stock VLT was gutless off boost, came on with a rush, and then done/gone at around 5-5200.  Brilliant in 1986 but that was a while ago now.

 

3.4 stroker for sure when $$ available, thanks for yor input, very valued ?

Edited June 1, 2018 by AngryRB

[GTSBoy]

25HP of N2O injected from 2000rpm onwards.

[AngryRB]

1 hour ago, GTSBoy said:

25HP of N2O injected from 2000rpm onwards.

Hmm but what about the manifold?

Edited June 2, 2018 by AngryRB

[admS15]

Hmm but what about the manifold?

Yep

[AngryRB]

17 hours ago, Dale FZ1 said:

3.4 stroker will give more torque at lower rpm.

Going down a size in turbine A/R will be counter productive especially with the 3.0 bottom end.

Can't see the sense in gearing it up with 3.7 diff.  A 4.1 will allow it to turn more rpm for a given road speed.  And give better response.

Stock VLT was gutless off boost, came on with a rush, and then done/gone at around 5-5200.  Brilliant in 1986 but that was a while ago now.

 

How would it be counter productive?

Isn't it all related to gas flow, so whether its a 2.5L or a 3L it will flow the same gas to make 300kw, only it will have better response?  

 

[GTSBoy]

The logic is actually fairly simple.

Taller diff gears put more load on the engine, so you will get more boost in lower gears with a taller diff.  This is good.  And in the 1980s, people like Corky Bell were telling people to make use of the extra torque available from adding a turbo to their NA car by using higher rear gears.  But between any two turbo cars that are identical except for the diff gears, the car with the shorter diff will accelerate faster in any given gearbox ratio than the one with taller gears.  It's dead simple maths there.

The difference can swing the other way when specific road/track conditions are brought into consideration.  If you can save a gear change on a straight by using taller gears then the poofteenth of a second saved going up and down a gear might make the lap faster.  Same on the strip.  Save a change at 95% of the run and maybe go faster.

I am of the opinion that my car (an R32 with 4.11 diff and a Neo) would probably be a nicer street car with 3.7 diff gears.  1st gear is really very short right now.  On a launch you really want to short shift it because it's just going to break traction anyway.  2nd gear not much better.  So if I had a taller rear in it I might get a slightly softer launch that retains traction and lets me run to higher revs (and consequently much higher road speed) in each of 1st and 2nd, making the car actually faster to reach any given road speed.

[Dale FZ1]

1 hour ago, AngryRB said:

How would it be counter productive?

Isn't it all related to gas flow, so whether its a 2.5L or a 3L it will flow the same gas to make 300kw, only it will have better response?  

 

Bigger engine will suffer from rising EMAP earlier.  And kill the ability to flow well, sooner. Will result in tractor type torque curve, fall off quickly as the revs get up.

[Kinkstaah]

You could do something like an EFR7163, but you'd be limited to running such low boost to stop it murdering itself up top that it'd really be hard to argue that it's a good idea.....

Alternatively, buy my turbo setup!

Note: nothing short of stupid is going to move it 1000rpm earlier though. 

[Dose Pipe Sutututu]

Twin Scroll, Twin gates, modern turbo, working VCT

[Looney_Head]

Mine isn't lacking down low, I have 4.34 gears and an rb25 box.

Setup is a rb25/30, twin scroll manifold, Borg Warner s360sx .91 twin scroll housing, tomei 256 poncams.

 

Made 378kws on 14psi with heaps left in the tune. Vct was on the whole run hence the drop in torque