RB26 -7 upgrade suggestions for optimum performance

[DJBarnstar]

I'ts built, and I understand that the previous owner had the head cleaned up. Seems to really like boost on E85. You can see on the graph that it is well and truly out of puff and starts dropping at that level however.

[DJBarnstar]

Also Castrol 10-60 here. Works well and is regularly on special for 50-60 bucks. The dude from mainlube recommended it to me and he does a LOT of filtergram tests. Said it was the best bank for buck oil on the market. Perhaps a little thick for some, but these engines get so hot, so quickly, I think its fine.

[TXSquirrel]

On 10/27/2016 at 10:57 PM, RBN1 said:

My 32R runs -9's @20psi, stock airbox (good for mid to high 300's), RPM adj cam gears, stock cooler , powerFC, Tomei Expreme Dumps>Racepace 3.5 full exhaust, nismo afms and 600cc injectors on 98 @336rwkw. (all Racepace built & tuned - they run Castrol edge 10w60 in it). Everythings well within limits with the current setup on track days, motorkhanas and hillclimbs. No need to get a aftermarket intercooler or pods. ECU choice, depends on who is going to tune your car. 

I've owned the car for 11 years now and when Racepace sorted it out a few years ago, it's interesting how much they changed back to OEM (as apposed to how much was swapped out for aftermarket)

Hi RBN1, I also have a pair of -9's ready to go in along with Tomei cam gears.  However, I am undecided on Tomei dumps, do you know if they help with high end or low end power?  Do you know what was your injector duty cycle when putting down 336rwkw?

 

[RBN1]

11 minutes ago, TXSquirrel said:

Hi RBN1, I also have a pair of -9's ready to go in along with Tomei cam gears.  However, I am undecided on Tomei dumps, do you know if they help with high end or low end power?  Do you know what was your injector duty cycle when putting down 336rwkw?

 

Hi mate,

I got the Tomei Expreme dumps for cheap (brand new) at the time. Most people go the HPI's over the Tomei's although at these power levels (<400rwkw), I don't think it makes much difference at all - RPM weren't too fussed about which ones I chose for my build and said the Tomei's were fine. If they do make a diff at this power level it'd be top end, i've yet to see someone do a comparison between stock dumps and aftermarket at this power level.

Can't remember what cycle but pretty sure they're >80% on 98. They're capable of around 360-380rwkw on 98 from what i've seen on other cars with similar setup to mine but -5's. I'll check and re-post re. cycle when my car goes back in for a checkup tune in the next month.

[Borci88]

Stock 32/33 dumps will flow to just under 400awkw on 98 pretty easily, beyond that you're gonna need bigger dumps. 

[Hadouken]

If I'm not mistaken 32 dumps are restrictive. It's 33/34 dumps that you want.

[r32-25t]

I wouldn't pull the turbos out just to change the dumps but I wouldn't change the turbos and not replace the dumps at the same time either 

[TXSquirrel]

My goal is only to break 300kw with -9's, so I never considered aftermarket dumps.  But since my engine will be pulled, I am feeling a bit of "may as well..."  

For a low power goal like mine, will aftermarket dumps make any difference?  How about ported manifolds?  Does that really create lag at the low end like OP suggested?

 

[r32-25t]

Bigger the dumps the faster it will come on boost, don't get the hks ones cause they create massive amounts of back pressure and come on really late

[WantGTR]

4 hours ago, TXSquirrel said:

My goal is only to break 300kw with -9's, so I never considered aftermarket dumps.  But since my engine will be pulled, I am feeling a bit of "may as well..."  

For a low power goal like mine, will aftermarket dumps make any difference?  How about ported manifolds?  Does that really create lag at the low end like OP suggested?

 

if you are pulling the engine out, definitely do the dumps. port the manifolds, get good quality gaskets. do as much as possible. removing the turbos with the engine out takes about 10 minutes. removing the turbos with the engine in takes about 10 hours lol

[Borci88]

15 hours ago, Hadouken said:

If I'm not mistaken 32 dumps are restrictive. It's 33/34 dumps that you want.

You would be mistaken, as the 34 dumps are the smallest of the three dumps. I wouldn't be buying bigger dumps for a 300kw goal, I wouldn't port the manifolds either. 

[Piggaz]

12 minutes ago, Borci88 said:

You would be mistaken, as the 34 dumps are the smallest of the three dumps. I wouldn't be buying bigger dumps for a 300kw goal, I wouldn't port the manifolds either. 

Not sure if serious... or taking the piss :/.

[Borci88]

Actually brain fart, I thought about it for 2 seconds and went YEAH THATS RIGHT. 33 bigger than 32.. but I'm still sure 34's are more restrictive than 33, but not enough to matter.

[WantGTR]

i dont get it, spend the money and get the largest bell mouth style dumps??

[Borci88]

Just now, WantGTR said:

i dont get it, spend the money and get the largest bell mouth style dumps??

And make 320kw with standard dumps, or make 320kw with HPI dumps? 

[WantGTR]

3 minutes ago, Borci88 said:

And make 320kw with standard dumps, or make 320kw with HPI dumps? 

hpi dumps. get those gases out faster. might as well upgrade stuff while its apart. not exactly easy working with those twins while engine is in the car.

[Hadouken]

Actually brain fart, I thought about it for 2 seconds and went YEAH THATS RIGHT. 33 bigger than 32.. but I'm still sure 34's are more restrictive than 33, but not enough to matter.

Still incorrect. This is well documented so I don't know where you are getting your information from.

32 is restrictive. The end. 33 and 34 dumps are verrrrrrry similar.

[Borci88]

2 hours ago, Hadouken said:

 

Still incorrect. This is well documented so I don't know where you are getting your information from.

32 is restrictive. The end. 33 and 34 dumps are verrrrrrry similar.

 

Did you even read what I wrote? I said 33 is bigger than 32, thus that suggests that I'm meaning that the 32 is the restrictive one (notice I played on that in the first sentence?).
34 is definitely smaller than 33 dumps, "but not enough to matter". So you essentially said I'm incorrect while agreeing with what I said. 

[Hadouken]

34 dumps flow more than 33. This is fact. And originally you said 32 dumps were better than 34. So yes I clearly read what you are saying.

Thank you

[Borci88]

9 minutes ago, Hadouken said:

34 dumps flow more than 33. This is fact. And originally you said 32 dumps were better than 34. So yes I clearly read what you are saying.

Thank you

Where is this a fact exactly? I changed my statement as I remembered the wrong dump. Everything that we've done on the dyno points to 32 being the most restrictive, while 33 being the best for flow, and 34 trailing ever so slightly behind it, but only marginal. How much testing have you done?