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First 1/4 mi runs in RB25det S14

justified2.4

By justified2.4,
in Engines & Forced Induction

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justified2.4 Enthusiast

justified2.4

Posted
Posted

I decided to take the s14 to the track for the first time today, very disappointing times, especially considering the weight differences between the s14 and r33.

First the mods:

-r180v LSD from CA18det (possibly hurt my top end)

-3" Blitz Nur Spec cat-back exhaust

-custom straight runner intake manifold

-Isuzu NPR front mount intercooler

-2.5" aluminum intercooler piping

-Greddy Profec B Spec II

-Sheepdog Prof BOV

All day I was running between 8-11 psi boost.

My best run was as follows:

r/t= 1.697

60 ft= 2.047

330 = 6.063

1/8= 9.269 @ 77.89 MPH

1000 =12.060

1/4= 14.396 @ 92.38 MPH

as I said, very disappointing, although much better than my stock times with the KA24de motor 16.3 1/4mi.

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DJ984 Mentor

DJ984

Posted
Posted
damn thats slow.. sorry.. but my stock rb20 silvia (s13) ran quicker than that. check everything. good luck.

I thought all silvia's where 4 cylinders??? (ie SR20, not RB20???)

could someone clarify this for me 'cause i also thought the S15 was an RB20 (6 cyl) but recently found out it's an SR20... or is it???

Need clarification....

Cheers.

justified2.4 Enthusiast

justified2.4

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Posted
I thought all silvia's where 4 cylinders??? (ie SR20, not RB20???)

could someone clarify this for me 'cause i also thought the S15 was an RB20 (6 cyl) but recently found out it's an SR20... or is it???

Need clarification....

Cheers.

Silvias come stock with 4cyl mainly SR20 and CA18, in the US here we got the KA24de (non turbo).

Anyone with 6cyl did the swap.

But yes I understand this is slow, I have had some problems with the car so I know there are issues. I should be running mid 13's. I still have the stock downpipe and cat so that is an issue. Also the 4.36 gears are not good for top end, I am going to switch back to 4.08 soon. Have to go thru and check sensors, also put some better grounds in. I have only had the car running for a few weeks now and untuned, so it is to be expected that the car is not going to run perfect just yet.

meggala Grand Master

meggala

Posted
Posted

dont be dishearted for a first time to the track check your timing as this could be a cause for a lack of power also you boost was probably more 8 psi than 11 also you might have reved the car way past the power band try changin a bit earlier did you change to 4th b4 you crossed the line.

still after all the talk you got the motor in and the car running which is great now come the refinement.

my first time in my r32 at the track I ran 15's. with tuning and practive I got it down to a 14.00 @ 99 mph that was an rb 20 with rb 25 turbo

the lack of mph in your time says to me timing and boost also your car could be running really rich which will affect power.

cheers

meggala

yes they do need to be finely tuned to make the power trial and error will get good results now you see why us aussie spend so much time on dyno's.

R31Nismoid Grand Master

R31Nismoid

Posted
Posted

:werd:

As you said... low-ish MPH. Not VERY low though.

But if you aint got a 3" dump pipe... that's the best place to start.

As boost should naturally rise to around 8-9psi anyways after that mod.

Wouldnt worry too much about your diff gears.

They play a part, yes, but not a massive amount IMO.

i have 4.11's...

And im still in 4th as i go over the line

I was in 4th when i ran the 12.9(109mph) and my 13.8(101mph)

rev210 Grand Master

rev210

Posted
Posted

leave the 4.36 gears unless you want a slower 1/4 mile.

The custom intake manifold and the front mount intercooler are possibly doing you no favours.The increased pipe length and total volume reduce the engine response time. As quite a few people have proven an intercooler around the same size as factory is ideal for the factory turbo.Also,the factory plenum is quite fine to over 500HP, it is moot whether the 'good' aftermarket ones are much better on mild tune engines at all.

Any overfueling between gear changes can be put down to the aftermarket BOV ( I bet the factory one works better) if you are still running the std ecu.

Basically if you had my stockish RB25det in your car you would be down the 1/4 in mid 12's easy. You have a fair bit to sort out by the looks.

The dump pipe and front pipe won't hurt either.You might like to put a de-cat pipe in as well.

Best of luck.

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