FREELIGIOUS

My 98 GSR has about 30k miles since a motor rebuild.

How much boost can the stock internals withstand with this turbo? I was thinking about running 10-12psi. I know people have put a lot more stress than that even on stock gsr motors, but I am curious about how safe it is.

The car will also be professionally dyno-tuned at a local performance shop using Greddy E-Manage Ultimate ECU. My tuner definitely seems to prefer to tune on the conservative side as well.

bigD

let your tuner decide what he thinks is safe

EsotericImage

iTrader: (8)

i would start at 7 and move to 10 and see how that holds up

boostedeg302

10-12 psi would be fine for that engine, especially with only 30k on it since rebuild. Do a compression check and see how healthy the motor is. These engines handle anywhere from 300-400 whp with no problem, many have seen much much more.

FREELIGIOUS

Well, I am far from 300-400whp. Right now I think my dynojet whp is around 220 to the wheels. Not too bad considering stock GSRs probably don't even quite put down 150hp to the wheels (just a guess since they are factory rated around 170bhp), but as a former h/c/i/e 5.0 Mustang owner, it definitely is not "satisfactory" power to me (still a LOT of fun, though). My boost gauge says 5psi, but it's weird, because I thought these kits came around 7-7.5psi. Either the gauge is bad or the previous owner turned it down somehow.

I would like to reach 300whp+ on my stock bottom end if possible. Eventually I will build it up, but that might be a while. Once I build it up I would like to put well over 400hp to the wheels. I may have to make upgrades to the turbo kit, but I definitely plan to stick with this turbo/ecu setup as it is one of the very few CA emissions legal setups you can build.

boostedeg302

The boost pressure depends on what the wastegate spring is and what the boost controller, if you have one, is set at.

FREELIGIOUS

Oh, I forgot to mention that I am also running an intercooler. Figured I should point that out since this kit didn't come with one and a lot of guys running it don't have one.

boostedeg302

what kit do you have?

TheShodan

iTrader: (14)

If it is a greddy kit with the pre-tuned e-manage, it will only work about 8.5psi with an intercooler. Greddy has the actuator set at about 6psi, and can only go about 12-14 without it being replaced or adjusted. This equals to about less than 300whp with the included downpipe.

boostedeg302

That is what I was thinkin but I didnt wanna assume that he had the greddy kit.

FREELIGIOUS

I will use that boost controller you recommended to get it to 12psi. I understand that the downpipe is very restrictive, I'm still working on a solution for that. Is that the main restriction preventing me from reaching 300whp+? Other relevant modifications are ported OEM intake, skunk2 3" cat back, and I may get some minor head porting/"cleaning up" done as well.

TheShodan

iTrader: (14)

That actuator and the downpipe is what holds one back. Try it with the included wastegate, if it doesn't get ya there after the dyno... time for an upgrade.

FREELIGIOUS

Is my only option for a bigger downpipe having a shop custom fabricate one?

boostedeg302

Im sure you can find one online somewhere to fit that kit. Just do a little searching around.

FREELIGIOUS

I've looked quite a bit, but haven't found anything, if you know of something please let me know.

The downpipe is in two pieces, the downpipe adapter and downpipe.

The actual downpipe is just a j-pipe that goes from the adapter to the catback, a simple and cheap fabrication that any exhaust shop could make cheap.

The downpipe adapter is where the restriction begins, as it tapers down to 2". Fabrication of this part wouldn't be so easy as it is made of cast iron:




Would a replacement need to be made out of the same material? Would ceramic coated steel suffice? I'm guessing no, but options are looking pretty limited at this point aside from swapping out the turbine housing.


.

wmac

the greddy turbo kits were designed to retain p/s & a/c as well as be CARB legal. Their implementation of the downpipe reflects this.
using cast iron is not cost effective except in larger quantites.
look at some of the ebay kit downpipes as well as some of the higher quality 'fabbed' downpipes.
they usually have a mild or stainless steel 2.5" or 3" 90* bend welded to a flange or 'v-band'.
even the tightest radius 90 would extend much farther than the greddy downpipe.
kteller usa, and wiertech canada have made downpipes for the greddy kits, but i don't know how much of an improvment they are.

90Rexx

my suggestion is enjoy your 200-250 whp as the car sits.

if your looking for more power, instead of wasting money modifying your greddy kit, just uprgade your manifold and downpipe and buy a larger turbo. that way you can sell your smaller stuff to recoup some of the costs.

FREELIGIOUS

I'm actually thinking the same thing. The cheapest route I see right now is getting a mitsu housing. But, I figure I might as well get a bigger turbo altogether if I were going to do that.

My main concern is going to be getting around the AC compressor. This car will be one of my daily drivers, and where I live it gets really hot in the summer, so I have no intention of ever taking it out.

I need to have more power. Maybe I'll stop missing my old Mustang so much Honda if my Honda is faster. For that I'd need to put down around or close to 300whp.

Hybrid96EK

I think first you need to understand the difference between the two and quit trying to make the 4 cylinder anything like the 5.0. It is what it is. The 4 cylinder will NEVER have the low end grunt that the 5.0 did. Period. Can you make it quicker? Sure. But its going to cost you some money, some time, and some of the stock OEM reliability. If you are willing to give these up, then proceed. There comes a point when one has to make sacraficies in terms of A/C, fuel mileage, etc. What do you want more? Cold air blowing in your face or 300+whp? You have to make these choices now becuase more often then not you can't have it all. Trying to make 300whp won't be too much of an issue with the Greddy kit, but much past that you need to face reality and ditch the Greddy kit. From the sounds of it, you should just ditch it now and go with a custom setup. Remove it every two years for smog and be happy. So long as you don't get caught with it, your good.

slick1851

YOU NEED A CUSTOM 3inch down pipe made for this turbo

(Im not talking about twin scroll evo 16g type turbos)


In the dsm world a 16g or a 18g standerd turbos will hit 400whp


dsmtuners.com and look at what they can do with poorer flowing heads and less compression


Hondas have better head flow and more compresion= good when it comes to making power


The problem is greddy made the kit 50 state legal and put in that shitty down pipe to fit the factory cat!

Hell even on a stock dsm or a older evo 15-25whp is gained from a larger 3inch down pipe and more spool also

Its crazy to even think people these days will run the greddy down pipe!

Oem sized down pipes will never make power!


You will see 300whp with a 3inch exhaust and honda data with at least 550cc or bigger injectors

slick1851

IM NOT TALKING ABOUT EVO EIGHTS and EVO 10s

THOSE ARE TWIN SCROLL AND TWO DIFFERENT STYLES

slick1851

No you have to not be cheap and spend the coin on a AC/PS capable manifold

They exist but there a couple hundred bucks more than the non ones

Honda people are to cheap in the masses to spend the extra cash

FREELIGIOUS

I think I might do what this guy did:

http://www.*************/forums/turb...-downpipe.html
EDIT: Can't post links to that site apparently, but if you google "greddy custom 3'' downpipe" it should be the first result.

It looks like he fabricated his own, but the t25 flanges can be found on ebay cheap.

90Rexx

if you want to go the route with the dsm flange, i have an exhaust housing for a GT30R or other 57mm turbo with a dsm flange on it so u can run a GT30R or similar right off a dsm manifold.

let me know if your interested im practically giving it away

blaze the chemi

I had a blast with my 18g in my B16. Granted the little boy in the Mustang GT I put a beat down on didn't have a classic 5.0, the point is I still waved bye-bye to him into the rearview mirror. This was with the crappy elbow in there only putting down 248whp. I also pissed off a lot of other cars thinking I didn't have anything under the hood.

I lost a lot of psi from 5700 to 8000 because of that restriction. If the torque curve stayed flat from peak torque my B16 would have put down around 315whp. Peak torque was at 15 psi and final psi was just at 12.

Be sure you upgrade your MAP if you are shooting for over 10 psi.