Well i am satisfied with the results but not super happy. My goal was 250 hp on a greddy kit. My best run was 242 hp and 215 tq at 13 psi. I was hoping to hit 16 psi. Waste gate wouldnt hold and it would drop from 13 to 12 near the top. If i had that extra 3 psi i would of been well past 250 hp goal. I think i have a leak some where cause i think boost should come on a lil sooner. If i upgraded my downpipe/exhaust im sure i can hit 250+hp.


oh yes...**** myself hard with some lube...i brought my camera...but the batteries were dead...sucks cause i didnt get any dyno videos and shity pics...the videos i got i just gotten converted to avi and they were horrible not even watchable...so onwards with the shity pics.

so what do you guys think? turbo running out of breath? slower spoolin then normal?



y8 head
crane cam
crane valve train
z6 intake manifold

y7block
cp pistons 9:1
Eagle rods
Polished/balanced crank

greddy 15g internal gate
greddy cast manifold
greddy 2 1/4 inch downpipe
apexi world sport 2 2.36 inch exhaust
50 mm bov
johnny race car intercooler

 

I wouldn't complain. Your butt won't know the difference for the 8 extra ponies on a D16y7/8 with that setup. The wastegate won't hold open because the spring is just too small to allow adjustments that high. Greddy has always used a rather restrictive wastegate system.

 

Upgrade that exhaust to 3inches and you'll pick up the extra horse you looking for...

 

well i konw an upgraded exhaust will help out alot.

restrictive cast manifold
restrictive 2 1/4 inch pipe
restrictive 2.36 inch exhaust

would this combined make the spool late?

and are these numbers comparable to another 15 g greddy set up at 13 psi?

 

That's pretty good for a 15g.

 

Not bad. Bet that fuel map could have been leaned out a tad bit more to get you some a bit more power.

 

Well, If it makes you feel any better I did the same thing forgot my camera on my first dyno run. And.. And.. I only did 255 with a 00 SI with built bottem end and Greddy Kit!! I sold that car..

 

^ doesnt make me feel better but WOW!

 

That is good numbers for what it have.

 

The 15g makes that much power at that boost level? Seems pretty high, or maybe the dyno was reading a little high. Those sound more like 18g numbers to me.

 

The greddy kits like stated have a shitty wastegate system. From the O2 housing down go 3" all the way and you will pick up some spool and more power. I did this bunch of times back in the day with the greddy kits in 2000. Thats some good number for a small turbo

 

it was a dynojet not sure if it reads high. I do have some supporting mods. When we were tuning it the Crane Cam really thirsted for more fuel it was leaning out. He was doing his base tune on a similar setup but with an oem cam...so hopefully the Crane cam was doing its job.

ya the wastegate arm i have basicly completely shortened couldnt get anymore out of it. I picked this exhaust cause i am getting old so i wanted quietness

as long as the numbers look good i guess im happy. The spool up time worried me a lil bit, but it seems like everyone agrees the 2 1/4 downpipe and exhaust is really restricting my spool time

 

thats wat i was thinking greddy kits dont usually make much power so i would say be happy wit wat ya got cause it seems damn good to me..

 

The bigger exhaust won't be worth the hassle and extra money. The 15g will max at 25X whp even if you had a open dp. The only way to see more psi on 15g is to take a small stiff spring (I used a t-belt tensioner spring) Use saftey wire and wire the spring up to help hold the actuator arm closed. You will see a spike to about 16-17psi, but it will quickly fall to ~15psi and hold. I put down 252whp on my stock bottom end Y8 with a crower cam.
Your graph looks very nice. I wouldn't spend anymore money on the setup, your at the limits of the 15g. I spent alot of time and money trying to get just a little more out off my kit, but a bigger turbo was the ONLY option for anything over 250.
If you want an easy 300whp just do a 19t conversion. (you can just find a used one from a EK kit, or send yours in to get a 19t wheel put in)

 

^thanks for the info. i have the arm so short that its basicly tugging on the wastegate with no play in it.

is the 19t a direct bolt on turbo? if so i may try to go that route. i just want a nice reliable street kit

 

The play really doesn't matter... it won't hold because the exhast pressure pushes the gate open from the inside. The factory spring simply doesn't have enough pressure to keep the flapper closed. Adding a spring on the outside will add to the pressure applied to keep it closed.

The 19t is a direct bolt on. It is the same turbo as the 15g, only difference being the compressor wheel is bigger. Like I said you can just send yours in to get the 19t wheel installed in your 15g turbo.

 

where do i send it in? i just did a quick search on ebay and such and no luck on a 19t. Ill have to wait a lil while cause this build and the dyno kicked my budget in the nuts.

 

sounds like good power to me with that setup.

 

I'm sure there are more options than these guys... but they have a cool vid to watch
http://www.blouchturbo.com/upgrades/

VID: http://www.blouchturbo.com/clips/upgrading101/index.htm

 

wow that looks like alot of pricey work for the upgrade! seems better to find a used one.

neat video none the less.

 

The 15G is best at over 2 pressure ratios, (over 20psi) so, this is not a suprise

 

Glad to see you got it together and running man.

If you're interested in a Y8 intake manifold, I found mine in my basement the other day.

 

So you're saying that it's not a surprise the 15g made 242 whp at 13 psi, yet it is better at over 20psi? So what would it make, 300whp? I thought the 15g couldn't flow that much air

 

to the OP: The greddy 18g is a direct bolt on, just have to grind a slight amount off the block. I would opt for that over putting a new wheel in the 15g, but that's just me.

 

^ya i knew about the 18g.

but i would need to find the greddy 18g with the downpipe...which is just as hard locate

im content with what it is right now. I havent had a car that ran perfect in almost 3 years...so ill enjoy not having to fill up coolatn every other day and driving long distances for now

thanks guys for all the input.