'99 Cobra motor with 16cc pistons, MP T70 .68AR, spools at 3K...is that right?

[Jonny00GT]

I got my car tuned today and it didn't build boost till around 3K on the street and later on the dyno. Is that right? I thought the low AR would mean earlier boost. I only wanted 500 and got 504/533, so I'm happy, I just want a fatter mid range and more down low. It's a blast when I plant my foot in it at 3K, don't get me wrong. Just now what I expected...


-Jonny

 

[Mike@TCI]

Sounds right to me... my 2v hit full PSI right at 3150 RPM with the .68 MPT70

 

[Jonny00GT]

Oh, ok. Thanks...I was expecting full boost at a lower RPM with that .AR. It does come on like a beast though!

 

[DTSVT03]

How much boost are making to get that up/tq #?

 

[Jonny00GT]

It zeros out pretty early, but build boost till almost 4000rpm on the dyno and hit 12lbs at 5000rpm before fuel would drop off.(only dual cobra pumps and 20amp BAP turned all the way up right now) On the street I saw 1lb at 3000 and about 3lbs at 3500rpm and it started building damn fast compared to the dyno cause of load, but didn't really get on it...weather has been too wet to screw around safely. I'll have to see what boost it makes at 4500/5000 on the street with a load once things dry out. Oh...and that was only 11deg of timing.

We were worried the wastegate adjuster wasn't working, but looks like it works fine since I have a 5.8lb spring in there.

-Jonny

 

[DTSVT03]

Those are pretty good numbers with 11* timing.

 

[Jonny00GT]

Those are pretty good numbers with 11* timing.

I'm happy. I would like to be able to pull to 6K and still be where I am in power. Once I takle the fuel system stuff, we'll hit it again, reduce the boost a little and maybe bump timing if need be. Not bad for my first try building my own motor, an eBay turbo hot side and fabing my own down pipe, etc!

-Jonny

 

[DTSVT03]

I'm happy. I would like to be able to pull to 6K and still be where I am in power. Once I takle the fuel system stuff, we'll hit it again, reduce the boost a little and maybe bump timing if need be. Not bad for my first try building my own motor, an eBay turbo hot side and fabing my own down pipe, etc!

-Jonny

Definitely not bad at all. My numbers were produced with 18psi and 18* timing, on a mustang dyno