ISIS RS3871 Turbo Kit (RS3371 Turbo used)

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Sugar
Posts: 160
Joined: Wed Jun 30, 2010 12:01 pm
Car: S13 w/ Sr

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I decided to do my own review now since the other thread wasn't mine to begin with and was cluttered.

Now a large reason I bought this kit was because everyone has something bad to say about it, yet nobody has any experience with it. I wanted to try the kit out as a t25 replacement, no tune of any kind, just simply bolt it on.

Engine:
S13 Black Top, Stock ECU, Stock MAF, Stock Injectors, Front Mount.
AEM UEGO for monitoring AFR's.

The Kit
Image

ISIS V2 Bottom Mount Turbo Manifold
As other people have said, it looks great. Welds look awesome and appear to have been dremaled smooth on the inside. I initially had fitment issues but it turned out not being related to the manifold (i'll get to this).

ISIS Turbine O2 Housing
As most would expect this looks and fits great, not much more to say really. Welds are again great and have been cleaned up.

ISIS Turbo lines
Turbo lines are great. The fittings are black, the steel braided line is wrapped with a high temp fabric which is black to match. Be careful to keep them off the downpipe and manifold though. Like nearly anything it will melt with direct contact. My coolant line was resting on the down pipe for the first run out and did melt threw the sleeving, no harm done though.

ISIS Intake Kit
The Intake kit is pretty basic, and in my opinion shouldn't be included with the kit. It may work with a 45 degree coupler off the turbo, other wise it's going to need some modification to work. It would be great with a stock t25.

And like it says on the webpage, the kit comes with all gaskets and hardware. The guy I spoke with when ordering the kit was very upfront about the kit, they recommended OEM gaskets as the kit comes with the cheap paper gaskets.

ISIS RS3871 Turbo
The turbo looked great, but its very big. Almost to big to fit, it does squeeze in there.The turbo was actually why the manifold was so hard to fit initially. The wastegate bracket was rubbing the motor mount. It also sits very close to the strut tower, and because of how its clocked makes the coupler hard to fit. I had to trim the coupler and it was still kinked against the strut tower.

After having some issues Ken was nice enough to send me a new turbo to see if it was faulty. I requested a smaller turbo only because of how tight of a fit it was (The issues turned out to be unrelated to the turbo however). He sent me their new turbo. I was told its identical to the GT2871R, only it is journal bearing. If I recall its the RS3371.

The turbo is much smaller, I had 0 issues with getting it to fit. It had plenty of clearance with the strut tower.

Results
The turbo is very quiet. I would say it spools a tad slow, but not to bad. Wastegate is at 9-10psi, and it gets there between 3500-4000. The car has significantly more power than the T25. I don't want to estimate any numbers but it feels really good. My friend has a KA-T, 550cc injectors, tune, and a t3/t4 turbo at 10psi and my setup feels a little quicker.

At WOT the AFR's read in the 11's, seems generally 11.5-11.9. Lowest I've seen is 11.2.

Overall the kit is great. For anyone considering it, I highly recommend it (keep in mind I am using the 3371, which I would hope they start selling soon). Enjuku did a great job in helping me out as well. Like I said they sent me a new turbo with no fuss at all.

I'm going to be rebuilding the engine this fall, I'll try to get some dyno results before and after injectors/tune. This car is drifted regularly so i will also chime in with how well this is holding up.


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PyR0NiAk
Posts: 4447
Joined: Sun Mar 01, 2009 4:29 pm
Car: S13 SR W/ T2 GT3071R .86AR, JWT S4 Cams, 810cc Injectors,Z32 MAF, JWT tuned ECU 87mm 9:1 Compression CP pistons, Manley Rods
Location: Ohio
Contact:

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The only thing that is getting to me, is you're still running stock injectors... T28s are able to max out the 370ccs injectors, but yet your 2871 sized turbo is just fine with them. How high are you revving?

Edit: Good review, by the way. It's nice to see people shedding light on the ISIS kit, and I REALLY hope they redesign that freaking intake pipe. I'm 100% positive people would rather pay another $10 - $20 for a proper fitting one than having to modify that one after they buy it...

Sugar
Posts: 160
Joined: Wed Jun 30, 2010 12:01 pm
Car: S13 w/ Sr

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I took it a little over 6,000 RPMS. I would say the car is pretty close to maxing it out, it feels pretty quick. I'll dyno it first thing after the engine is rebuilt though.

On the same thought I guess, I have always been curious to how a larger turbo increases power. The overall volume is hardly changing at all, my friend mentioned the velocity of the air, but I would imagine that being relative to engine speed and not effected much. Im speaking of a larger turbo at the same pressure.

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PyR0NiAk
Posts: 4447
Joined: Sun Mar 01, 2009 4:29 pm
Car: S13 SR W/ T2 GT3071R .86AR, JWT S4 Cams, 810cc Injectors,Z32 MAF, JWT tuned ECU 87mm 9:1 Compression CP pistons, Manley Rods
Location: Ohio
Contact:

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Larger turbos compress the air better.. (more per volume)
Another though on this is why turbos stop making power once they leave their efficiency range.. They stop compressing air and instead, blow hot air...

devlmaycry
Posts: 169
Joined: Tue Jul 03, 2007 2:47 pm
Car: 95 Nissan 240sx S14.5

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Yeah I've been looking at that kit for a while now and wondering when someone would buy it and write a review. So, did you use the 3871 or the 3371? It would be nice if enjuku or isis would post up some numbers for the kit so people could get a better idea of how it performes compaired to the popular gt2871r.

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PyR0NiAk
Posts: 4447
Joined: Sun Mar 01, 2009 4:29 pm
Car: S13 SR W/ T2 GT3071R .86AR, JWT S4 Cams, 810cc Injectors,Z32 MAF, JWT tuned ECU 87mm 9:1 Compression CP pistons, Manley Rods
Location: Ohio
Contact:

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devlmaycry wrote:So, did you use the 3871 or the 3371?
Title has your answer. :)

devlmaycry
Posts: 169
Joined: Tue Jul 03, 2007 2:47 pm
Car: 95 Nissan 240sx S14.5

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PyR0NiAk wrote:
devlmaycry wrote:So, did you use the 3871 or the 3371?
Title has your answer. :)
"After having some issues Ken was nice enough to send me a new turbo to see if it was faulty. I requested a smaller turbo only because of how tight of a fit it was (The issues turned out to be unrelated to the turbo however). He sent me their new turbo. I was told its identical to the GT2871R, only it is journal bearing. If I recall its the RS3371"

Sorry I had seen the text above this, where I bolded the rs3371, and was curious as to if the op had meant 3871 instead. Thansk for clearing it up though.

Sugar
Posts: 160
Joined: Wed Jun 30, 2010 12:01 pm
Car: S13 w/ Sr

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Its been 5 years and the turbo has started blowing smoke.

I've been running 20PSI with 550CC injectors and Jim Wolf S4 cams. I've been to probably 15 drift events along with some spirited driving in my area. The car gets driven often and hard. This is hardly an update, I actually just stumbled upon this thread and realized it was mine :chuckle: . I will be getting another ISIS turbo to replace it. To anyone on the fence about the ISIS turbos. Go for it.


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