I had to start another thread, since this point was brought up by RacerXtreme7 inside another thread, and it didn't get addressed properly...

RacerXtreme7 had argued that the P-trim was the ideal turbine wheel trim to use on a 13B.  The Garrett P-trim is proven with 13B applications.

I had argued why not move up to a bigger, Q-trim turbine wheel?  RacerXtreme7 argued that the Q-trim turbine would be too big for the 13B.  So what's stopping us from just necking the Q-trim down to a smaller turbine A/R?  If the turbine section is too big, dropping the turbine A/R should compensate for this "problem".

Does the larger Q-trim wheel just too physically large that the 13B cannot push it even though we play with the turbine A/R housings?

I know there are some "racers" who use the Q-trim turbine wheel on their 13B's...  Is the Q-trim not a streetable combination?


-Ted

 

Plenty of people use Q trim.

I think his point was that you were arguing that a Q trim would spool faster than a P trim and him and a few other people disagreed with you.

 

Yes the Q trim is very streetable. A .84 garrett, or .81 T'Netics are very nice in a 66-67mm turbo. Your best bet in the other thread is to look at a T66, but even there the P trim is a little faster.

 

So why would the smaller P-trim would be favored over the larger Q-trim (with smaller A/R)?  I would think trying to get the backpressure to a minimum would be desirable?  At a certain point, the Q-trim with the smaller A/R would spool faster than a P-trim due to the larger turbine wheel fin cross-section - it's just a matter of have a more efficient passage to eject the exhaust gases out of the engine/turbine housing?


-Ted

 

I'd like to know also. Wouldn't a Q-trim with a smaller A/R housing respond faster at higher RPM's than a P-trim with a bigger A/R housing? It seems that at higher RPM's where the engine is moving more air, the smaller housing with a Q-trim would be able to direct the air straight into the wheel instead of wasting time filling up the extra volume of a larger housing using a P-trim....?

 

I think we need to define what is "big" and "small" in reference to turbine a/r's. I would call a .84 small and 1.15 large. When I bought my turbo, I went the route of using a 1.15 P trim b/c the P trim wheels are cheaper if an apex seal tears it up and I figured that the 1.15 a/r would help with flow....and it was during a time that everyone was talking about great performance with larger a/r's (1.15 and larger). If I was looking to push up around 20-25 psi and/or looking for greater than 500 rwhp I'd probably switch to a Q trim. But at that point I think I would want to go down to a 1.00 a/r.

From what I understand...
Turbine a/r should most directly influence spool time
Turbine wheel sizing/trim should most directly influence manifold backpressure and general system flow
BUT, these two are of course inter-related.

What confuses me is that there seem to be some "freak" scenarios of people running VERY large a/r's and speaking of "great" spool time. I think we all need to quantify what we are speaking of more clearly. People are posting of their new setup that "spools at ___rpm" or "reaches full boost at ___rpm". We need to all speak the same language. I've been trying to play this in all the threads with different setups and people posting their results, but it seems to lay on deaf ears.

If the above info is true, why isn't everyone running .84 a/r with an R trim with a large compressor on their race/street cars??? I must have some mis-info on the effect of turbine a/r's and turbine wheel trims?

 

In reference to 13B applications...
"Big" is over 1.3 A/R.
"Small" is under 0.8 A/R.
Normal is anything from 0.8 to 1.3 A/R.


-Ted

 

{QUOTE}:RETed "RacerXtreme7 argued that the Q-trim turbine would be too big for the 13B." {QUOTE}


Ted,

I never said ANY such thing. Don't spread misinformation or make me out as I don't know what I'm talking about with lies. Go back and read ALL my responses on this topic.


{QUOTE: RETed "I had argued why not move up to a bigger, Q-trim turbine wheel? RacerXtreme7 argued that the Q-trim turbine would be too big for the 13B. So what's stopping us from just necking the Q-trim down to a smaller turbine A/R? If the turbine section is too big, dropping the turbine A/R should compensate for this "problem"."{QUOTE}

LOL.. first off you never argued that point... not even a little. Are you having arguments with me in your head?? You argued that a Q trim spools faster then a P trim, and you are wrong. Don't make the argument out to be something different. (bet your hating the new rule of editing only after 1/2 hour huh?) Again, I never once said the Q trim should not be used on a 13b, all I did was give information that a P trim is great for a street car and flow sufficiently enough to produce well over 450 on a given set up and the Q Trim is 450-500 and over.

I stated that the Q-trim is for TOP END power. And it is. I never said its not appropriate for a 13b, I said high power top end 13b's. The Q trim is used on 13b's, usually in the 500 WRHP range. A very VERY common and popular turbo is a T66 with a 1.00 or .84 A/R Q-trim.

My response on this matter in the original thread https://www.rx7club.com/showthread.p...hreadid=261708

Direct quote from me in that thread;

{QUOTE}: RacerXtreme7 “P verses Q trim turbine wheels.

The Q spooling faster then a P trim is WRONG.

T4 framed turbine trims go in the following order from small to large.

N, O, P, and Q trim. There exist an R trim also that is exclusive to either Turbonetics or Innovative (I don't remember which).

P trim is optimum for any street and road race 13b powered vehicle. Q trim is usually reserved for all out top end power and usually uses a smaller turbine A/R to gain some spool back but still will out flow the P.

The Q trim wheel is NOT a P trim with bigger paddles welded on or casted into it. It is it’s own wheel design and not only does it have a larger inducer (major diameter) but it also has a larger exducer (discharge, or what you'd see looking at the back of a turbo).

P-Trim wheel: inducer/major dia. 2.922” , exducer dia. 2.544”
Q-Trim wheel: inducer/major dia. 3.111” , exducer dia. 2.693”

Also NOTE: If anyone decides to go with the Q trim wheel this means you will have to go for the “Big Shaft” option adding hundreds of dollars to the turbo chargers cost. But in most instances people electing to go with the Q trim option will be running LARGE compressors which puts the turbo charger in the “big Shaft” category.

TRUE..... a larger turbine inducer (major diameter) will help quicken spool up due to having more leverage on the shaft ( low energy diesels use large turbine blades to spin their compressors), BUT the Q trim has a larger exducer as well, so its a slower spooling turbine. Turbines work on pressure differential from the inlet (exhaust port to the turbine) and the turbo's discharge port (were your down pipe bolts or clamps). A smaller exducer will yield more restriction and a higher-pressure differential thus quicker spool (same reason going from restrictive stock exhaust to a hi flow unit quickens spool, you altered the pressure differential), but less top end due to backpressure. The P trim is good for 500 wrhp, so don't think of it as a "restriction" but a great compromise of spool and ultimate power.

The newer GT series turbines (GTQ) are GREAT. The T4 sized P-trim equivalent spools like a P trim but flows like a q trim.

~Mike.................. {QUOTE}

Note that I made the comment about Q Trim and smaller A/R’s FIRST. I also stated (as just did someone else) that going Q Trim will drive up the cost of a turbo build significantly.

In another thread on the same subject (sorry nyt for high jacking your thread, and good luck with your car)

https://www.rx7club.com/showthread.p...5&pagenumber=1

and a direct quote from me again.

{QUOTE}: RacerXtreme7

And if you believe the Q-trim will spool faster then a P-trim you are REALLY misinformed or, rather then amazing forum members with your brilliance you like to baffle them with bullchit. Funny you didn't reply with your remark back in the proper thread about this TED. You want to make snide remarks? I recall in your fc3spro web site (don’t get me wrong here, it’s a great resource and I commend you on doing it for the community) but at one time you listed that a turbine clip WILL spool faster due to weight loss… 100% completely WRONG. I corrected you on this in a thread once not directing it to you. Funny now the correct info is there now on the site. You also used to state a 60-1 will NOT make 400 wrhp on a 13b nor would a T04E 60-trim, MANY people are making 400+. You do contribute some good things to the Rx-7 community, but you need to be schooled in the world of turbo’s. We all know you have a hard time admitting you either made a mistake or your wrong. https://www.rx7club.com/showthread.p...298#post2573298

https://www.rx7club.com/showthread.p...threadid=253903

~Mike...............{QUOTE}


Sorry forum members for not directly contributing the thread, but things were implied that I had argued points that I had not. Also a lot of the info I originally stated is being confirmed by many forum members.


~Mike……………

 

Since you were kind to requote everything, this is the particular statement I'm arguing[sp?] against.

Your basic gist of your reply was to imply that the Q-trim would never outperform the P-trim in all facets of turbo performance and that the P-trim was your preferred turbine wheel for the majority of (street) applications, right?  If I am wrong with this comprehension, I welcome the correction.

With that said and done, I was trying to solicit opinions that would prove that a Q-trim turbine wheel can outperform the P-trim turbine wheel, even on the street.

Why you getting all defensive?
I'm guilty of being too lazy of quoting the entire discussion we had in the other thread into here, and I just put a very succinct summary of what we were beefing about.  Is my comprehension that bad?  Blame my 400 English SAT scores for that one...


-Ted

 

Ted,

Your question and reason for posting this thread is a good question and 100% legit. Its an intelligent question. The problem I had is you had certain arguments or were trying to figure or think through something in your HEAD and some how your arguments amongst your self I got my name thrown in. You miss quoted me and made it out that I was saying things I was NOT. That’s all.


Wrong. I'm implying and stated specifically the P-Trim is best for the streets if spool and power is a concern. The Q-trim is more for the huge HP numbers generally reserved for the guy wanting to run on the strip or a very large race circuit were an early power band is not needed or a narrower but more powerful power band can be used.

Can you run the Q-trim on the street? Sure, everyone seems to have their own perception of what lag is. Too each there own, but put a 500 RWHP (or even 400 wrhp+) “laggy” car on a auto cross track and watch what happens. They’ll never see boost, and if they do it will be in a *** out Smokey blaze of glory (which isn’t fast on a auto X track or tight road course). Like I said, to each there own..... nothing wrong with feeling the thrust of a T78, T66 etc. 500 hp car. But for throttle modulation and linear boost response (things I like on the street) your better off with the more "conservative" (by no means conservative to the rest of the world LOL) and more responsive, smaller T04e's, T04s's etc running P trims. Not everyone’s into that, some just want ***** to the wall all out POWER.

This is an interesting (though not new or hasn’t been tried) idea and I welcome all responses and debates

Its going to be hard to find someone with a base set up to pay for all the parts and dyno time to switch from p trim to q trim and change nothing else (but tuning) just to find out what the dyno sheets look like.

In the end, I think the results will simply be this.....

The P is going to out spool the Q, but making less peak power. The Q of course making more top end even using a smaller A/R but still yet not spooling as fast as the P. I believe the Q should be reserved for those making 500+ wheel HP.

“Q trim Out perform the P on the streets”, depends on your opinion of “street performance”. If your choice is a peakier narrower but huge power graph sure, but if you prefer a earlier, quicker boost response that’s more linear and still flows enough for 450+ hp, then no. In a drag race comparing identical set up cars with same compressors, porting etc, the Q trim will probly win making more peak hp, also in a drag race you won’t fall out the power bad even though its narrower. On a small or tight road course or auto X my money is on the P trim.

In the end again, if I’m wrong,,, that would be GREAT to discover that a Q-trim with a smaller A/R will both out flow and out spool a P trim running a larger A/R. But as of now this practice is only run on LARGE compressor set ups. It would be very interesting to see what happens on a smaller T04s (60-1) sized turbo.

Keep in mind there’s a "R-Trim" turbine wheel that’s exclusive to Innovative turbo. It will out flow the Q Trim with ease, although I don't know the inducer diameter, you can bet its either P Trim sized inducer or bigger and its a 0 trim unit. 0 as in ZERO trim, its inducer is the same size as its exducer, and get this...... its a 10 blade and is made of inconnel. talk about flow..........

~Mike...............

 

http://www.innovativeturbo.com/cgi-b...rbo/index.html
link to the innovative turbo site

 

I would say it has more to do with application than anything, but that not withstanding if it were me I would go larger trim, smaller housing for two reasons, one stronger shaft, two I would think a larger exhaust outlet would pretty much cancel out the idea of more backpressure from smaller A/R or pretty close anyway and still make good power. That being said I say go with GT series wheels and be happy.

-Sean

 

.... my experience with a T66 P for the street is the 0.96 didn't get spicy 'til way up high in the RPMs and even then it was explosive. Changing to an 0.81 has made the turbo way more streetable and fun; it comes in much sooner and it is working great. I'd hate to have a 1.15 under the hood. Of course, porting and so many other factors must be considered.

 

Get your hands on a new GTQ wheel and have the best of both. Lighter and improved aerodynamics.

jeff

 

Mark, maybe at SS7 we can trade, I will be running a .81 Q trim T66. The GTQ wheels are the **** for sure, a .84 67mm turbo with a GTQ wheel is a beast, ask CARX7 I wish I could get a GT40R with a .84, Sean???????????????????

 

Hi guys,

I have an Innovative T70 dual ball bearing w/Q-trim wheel. I have a 0.81 A/R and 1.15 A/R turbine housngs that I have access to. Its going to be used on a Cosmo 13B-RE motor basically stock motor with new internals.
Hoping for around 500hp at the wheels ... Street car , ocassional Strip runs (1stgen Rx7). Any advice on this combination would be appreciated.

Thanks

 

I have a Turbonetics T04S "N-trim" compressor (not sure what this means or what a/r) with a .89a/r Q trim turbine. Not installed yet, but it'll be going on a KDR street ported 3rd gen. I want 400-425 whp with the best spool possibly for that power (without the cost of the GT series of course).

I bought the turbo used because I thought it was priced right. Will I be disappointed?

 

Interesting old thread, I ended up running the PT67 .81 P trim 500rwhp@23psi, works very well on the street, and AX(with 13" slicks). I never put the T66 .81 Q trim on, but my 67 is damaged, so I may try the T66 in the next month, if so, I will dyno it with the same settings as the 67 P trim.
I think a .89 is an on center undivided, I'd like to see a picture of it beside a standard Tangential housing. The .89 Q trim is actually a bit larger than you need for that power, a P trim would easily hit that number at 15-18 psi depending on set-up, is it a 4 bolt outlet? Carl

 

yeah it's a 4 bolt on center non divided housing

I wouldn't mind switching to P-trim with a v-band outlet housing, could I do this and still keep the "big shaft" so I could retain my center section and compressor?

 

make that a t04B I have with N-trim compressor, not a t04s

 

Look to be a few years too late but I have to say that this thread looked like it was showing some real promise, so it makes me want to ask if anyone has meddled with the gtq trim on a 66-67