Say i have a t3 with a .48 ex and a T3/T4 with a .48 ex with basically the same size wheels......How much slower will the T3/T4 spool? Alot of people tell me that there wont be that big of a difference...anyone know from experience with both?

The reason i ask it im currently running a T3 with .48.....But i have a Turbonetics T3/T4 with a .63 just sitting here.....thinking of getting a .48 housing and converting it so i would get more top end. I know i will loose some spool up time but not sure how much?

 

Spool up will be the same because the turbine are the same, the power band will be much different though.

 

power band would be moved up higher in rpm and not drop off quick like the T3 right?

 

The compressor wheel is bigger, weighs more, takes more to spin it. It will begin to spool at about the same time, but won't fully spool as quick.

Given the power it will push due to greater efficiency it's a moot point. I think you should try both .48 and .63 turbine housings out on your setup, see how you like both.

 

Well i used to have the T3/T4 with the .63 on it because it came with my Drag kit....But that turbo was way too big for my sohc del sol and took way too long to spool....now im running a T3 with the .48 and the spool up time is sooooo much better but the top end isnt near the same.....thats why i wondered about converting the T3/T4 to .48 to get the best of both and go in the middle.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by J. Davis &raquo;</TD></TR><TR><TD CLASS="quote">The compressor wheel is bigger, weighs more, takes more to spin it. It will begin to spool at about the same time, but won't fully spool as quick.</TD></TR></TABLE>

Actually compressor wheels are so light that the difference in size doesn't make any noticable difference. Compressor design is all about efficiency.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BoostedD15B7 &raquo;</TD></TR><TR><TD CLASS="quote">Well i used to have the T3/T4 with the .63 on it because it came with my Drag kit....But that turbo was way too big for my sohc del sol and took way too long to spool....now im running a T3 with the .48 and the spool up time is sooooo much better but the top end isnt near the same.....thats why i wondered about converting the T3/T4 to .48 to get the best of both and go in the middle.</TD></TR></TABLE>
How much boost are you running with the t3, what are you planning on running with the other?
Just trying to think of a good suggestion...

 

right now im running 8psi with the T3 but it doesnt have near the top end like the T3/T4. And in a few months im planning on getting inj and hondata and running 14 psi.

 

quife

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BoostedD15B7 &raquo;</TD></TR><TR><TD CLASS="quote">right now im running 8psi with the T3 but it doesnt have near the top end like the T3/T4. And in a few months im planning on getting inj and hondata and running 14 psi.</TD></TR></TABLE>

At 8psi I would wager that the lack of top end is caused by something else. A t3 should be plenty big for a 1.5l even at 14psi. I really have to believe people go way to big on turbos, which isn't a big deal on a race car, but not as fun on the street, since it takes forever to spool. When I ran one on my 1.6sohc vtec with no exhaust it spooled up pretty quick and had GOOD top end, it just wanted to keep pulling well past redline.

 

Well i know that it is running super rich.....that may be causing my loss in top end power.

The other thing is the ex. wheel is clipped for faster spoolup.....Will this affect my top end?

 

hmm

 

Running super rich will hurt the entire powerband, especially top-end.

 

Does anyone know is clipping the wheel affects top end?

 

I was under the impression that you clipped an exhaust turbine to gain top end at the sacrifice of some additional spool-up time. Since there's less surface area on the wheel it takes more exhaust gas to get it spinning, but it is also less restrictive when it is spooled up.

 

cool thanks.

 

I have a .48 T3/T4 Garrett, I was getting full boost at 3500rpm on my 99 Si.

Just trying to give you some ideas on response numbers.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 00SilverLS &raquo;</TD></TR><TR><TD CLASS="quote">Spool up will be the same because the turbine are the same, the power band will be much different though.</TD></TR></TABLE>

exactly correct, seeing as the turbine wheels are the same.