Can someone list the different trims that are used in turbos???

 

No advice on trims?

 

Sure, right after you list all the different interior trims that are used in automobiles.

 

V trim
P Trim
Q trim

There are loads of others but thats the 3 you normally come across

 

I really did not know that there were so many different trims....
I was asking just for the basics!!!

What are the differences in the V, P and Q trims????

 

Q trim flows more than P trim which flows more than V trim. and thats just the three that came to mind in the second i replied to this thread

 

so uhm, that just mean Q is better, or what?
less lag, less power?
more lag, more power?

 

Dude... Get a good book and start reading.... And no bigger is not always better..
Basically the bigger you go with the exhaust housing the more top end power but you saciface spooling time..

 

Here are two good books:

http://www.amazon.com/exec/obidos/AS...981161-8072841

http://www.amazon.com/exec/obidos/AS...981161-8072841

Heck, maybe if you read them you will find out that "trim" also applies to the compressor wheel.

 

Understanding trims is one thing, but what trims seem to lend themselves to the rotary?
Say, for example I want to run a T66 on a street ported 13b-REW? What would be the best trim (O,P or Q...) /exhaust housing combination. Best meaning a good trade off between spool up time and peak power for a daily driven all around go fast car?

 

This thread has got me thinking.
If a Q flows more than a P which flows more than a V, then is it better to put a high flowing wheel in a small exhaust housing or a low flowing wheel in a large exhaust housing? It seems that most people go for a P trim in a 1.00 - 1.15 A/R housing for a nice powerful road car which seems to be a compromise on both sides. Why do they choose this instead of say a Q Trim in a 0.84 A/R housing?

This might be too difficult for the average person to answer but if anyone can give me at least a partial explanation I would appreciate it.

 

.....compared to the O and P. I've tested the Q trim ball bearing with the .96 back and was able to get only 25-27 max psi with the wastegate fully closed on a street ported 13B. The turbo wasn't laggy but it came on slowly compared to the .81 Q.

I think a Q trim with a small a/r (TANG/DIVIDED .70 Q pn-30254-4D) would be perfect for street/strip turbo. Has anyone tried a .70 Q trim setup?

 

i am also looking for help with turbine trims. want to use t66
size compressor at a maximum boost of 22 lbs on the street
my theory is that with a somewhat small(.96-.84) turbine housing
with a midsized turbine wheel, and a large wastegate one would
see the benefits of quick spooling and high exhaust flow at top-
end, thus not "choking" off topend horsepower.

 

I believe you are desribing what I call "the best of both worlds"...

 

Evil Aviator, thanks for the book references, I'm going to pick up the one on turbo systems setups. I see so many of the same questions on here all the time, I think I'll just start reading as many books as I can and come here if I have questions about applying the knownledge to rotories. Look at Rice Racing... Mechanical Engineer + Rotory experience = fast cars The last thing I want is a mechanical engineering degree, but I'd still love to pickup up detailed knownledge on the cars I'm working on.

-Brian

 

"the best of both worlds", yes sort of. i, myself, am interested in finding a turbo combination that would be more suitable for road racing, rather than ultimate topend horsepower for dragracing. keeping in mind that peak power would be in the 450wrhp range with good spoolup for a broad power curve(area under the curve).would very much like to hear others ideas on the subject.

 

The combination that you are refering to is rather small, but has quick spooling and power to the top end....
The setup that I will be putting into my 10th AE is a TO4 60-1, .96 a/r, 1.15 divided housing...
Told that spool up is at 3600... But yet has power to redline...somewhere in the range of 400 rwHP....

 

>>>>>>> .....compared to the O and P. I've tested the Q trim ball bearing with the .96 back and was able to get only 25-27 max psi with the wastegate fully closed on a street ported 13B. The turbo wasn't laggy but it came on slowly compared to the .81 Q.

I think a Q trim with a small a/r (TANG/DIVIDED .70 Q pn-30254-4D) would be perfect for street/strip turbo. Has anyone tried a .70 Q trim setup? <<<<<<<<<<

Hi Wayne,

Going back to a .70A/R just to minimize lag is a NO-NO !!!

Compare all three housings (.70, .81 and .96 A/R) at the mouth where exhaust enters..... your motor has to push the exhaust thru that opening and with a .70 A/R you're choking the engine!

The Q-trim wheel is too big for street/strip 13B !! unless you're in the Abel /Flaco HP territory.

You're simply reducing A/R size to gain in exhaust velocity to push that big/heavy Q-trim wheel.

I rather run a P-trim wheel and go up on A/R.....even higher then 1.00.....that's where the motor breaths and makes more hp.

Did you ever see the size of the turbines and headers on the Toyota GTP cars making 1000+hp on 2.0 liter 4 bangers ?

Later,
John D

 

Hey John, I'm thinking about a turbo for the street for my car. The .81 works perfecly for racing. the .96 needs a little juice to bring it online earlier.

The reason I ask was because, The blue Tubo II (with the Wolf 3D" ran 11.3 with a .70 "O" trim turbine . And that is really small. If his car ran that good with an "O" . I was just curious to see if anyone tried the .70 with a "Q".

This is for my 93. I already have a .81 Q but i figured the .70 would be very responsive and also flow a lot more air than the "O".

 

John this supra isn't getting choked up.
Check out this link I found running a seach.
http://www.suprastore.com/no8.html
I think I'm going to try it out. If I do I'll let you know how it works out.

 

Hi Wayne,

Have you ever noticed when HKS or Greddy sale the same turbo as an upgrade for the Rx7 or Supra the A/Rs for the Supra will always be smaller ??
That Supra is running an automatic and 100 NOS !!!! nice numbers regardless....
I honestly feel that a .70 A/R is quite small. When you increase your turbine inlet pressure (TIP) you will lose HP since the engine will work harder to push the exhaust out from the exhaust port.

P-trim has worked for the most (13B-turbo) and many simply change their A/Rs to get the required window of operation for their engines.

Let me know how it works out....

John D

 

boostn7
point well taken. my idea is to use a moderatly small turbine housing( as compared to the compressor side) with a moderatly small wheel, to get quick spoolup. once the desired boost pressure is realized(most likely less than 25psig) the large wastegate supplies the needed topend flow. i know this will not work with high boosted engins(more than 25psig). going this route i believe high HP is possible(400-500).

 

I've heard of Mitsubishi's making up to 600 HP with .58 a/r ratio's.
It is true with these piston guys you can get away with smaller turbine housings.

This .70 Q would just be for quick response on the street. but without the small outlet as an O or P trim.

I thought about this after seeing a .70 "O" trim running a t 88 supra in the 1/4. Not only did the rx7 miss third but was able to pull in the supra.

I'll let you know how it works out if I decide to try it out.

 

even a RB26DETT motor from a GTR Skyline (the closest equivalant to a 13B in boinger terms uses a smaller A/R exhuast housing to make the same HP

Rotary's need exhaust flow to make HP, end of story

 

End of what story? There are numerous trims and A/R ratios to choose from. I've tried the .81Q, .96Q and wanted to know if anyone tried the .70Q. So far I guess no one has tried it, but thanks anyway for your input.