Trav

Alright, so I think this time it actually IS time for me to select the real turbo for my RE swap into my 'vert (details in thread in my sig). At the moment I have a very small TO4e sitting on the manifold strictly for fitment. I bought it several years ago w/o knowing the exact specs and long before I had an idea about what kind of a turbo a rotary needed. I think it's like -47 or so -- VERY small...

Anyway, here's the scoop. 13bRE with LT8 -- stock port (no rebuild). If I ever actually rebuild it, then likely a mild or slightly agressive street-port at most. 800cc primaries, 1600cc secondaries fed by a single Walbro. Stock exhaust ports for the RE -- so keep in mind I MAY have a slightly slower boost response than a comparable 13BT (although I have no concrete data to support or deny this). Would like to get a RELIABLE 350-400 RWHP -- maybe even 450, but that's max. This would be my 2nd car, but a street driven car, so drivability is a must. That also means fairly good boost response is also necessary -- I see claims of full boost by 4000 and that sounds pretty good to me... The car may see the autox MAYBE once a season -- I'm really not into it, but I'm also thinking with this car I might GET into it. Car would also see the drag-strip probably 2-3 times a year for import events and whatnot. Not real sure what to expect with those kind of HP numbers but I'd like to target mid or low 12s. Heck, if I pulled an 11.99 I'd be ECSTATIC!! Reallly I'm building this for a driver, not a racer...

Best gas I can get here is 91 octane. I'm not opposed to running water injection, but I don't want to tune for that -- that would potentially only be a drag setup or simply for those really hot summer days. Also, I probably won't be building that from the start -- that would be an add-on for a later date. So, with that, I'm thinking PSI in the 14-17 range at most.

Overall goal -- A nice daily drivable car with significant power under the hood, but I have no desire to play the HP or the dyno queen game. I just want something that is very fun on the streets and a lot of fun on the track (straight or twisty). Tuned for reliability -- not for peak numbers. Decent boost response. Enough to get me in trouble quickly, but not enough to kill the pocketbook or someone else.

So my question is: Is this Garret TO4R that I read so much about, really all that it's cracked up to be? I mean really it sounds like the "ideal" all-around turbo without going ball-bearing... For me, I don't think the extra cost of the BB justifies the performance difference, but I could be wrong -- I don't have experience with either.

So here's what I'm thinking, get the TO4R from CheapTurbo.com with the wet center, v-band, maybe even HPC coated. Go P-Trim with a 1.0 divided hotside to help with spool but also give me plenty of room up top. Base price is $989 -- I can't see the price of the "options" anymore, but I'm guessing somewhere in the $1100 or $1200 range for the turbo. Is there really any other (non-used) turbo out there for this price with the performance and spool characteristics and is cheap to maintain (rebuild) if necessary?

Looking for input from those of you who've owned/used this turbo, but also from the guys that have experiences with multiple turbos -- just would like some objective comparison opinions. Honestly I'd like to buy 1 turbo and be done for good on this car. I've read a lot of comments and it just seems like this turbo gets recommended a lot for goals that are similar to mine. And from the few comments I've been able to find from those that actually bought one, they seem to really really like it.

Thanks guys -- mostly I'm just thinking out-loud and rambling, but would appreciate your opinions and reassurance that it would be a wise and economical choice for my goals. THANKS!!

signofinfinity

14-17 psi on 91 octane? I am no expert , but with 93 octane I wouldnt dare go over 15 psi. Others might agree that with 91 and no WI, I would limit my boost drastically.

I got my TO4R and I will be installing on my fresh rebuild (again) but the spec you mention are the way I ordered mine. with WI and boost in the 22 psi you should see the 500 mark so it should be within your targets. I base this on compressor maps and on what some gurus here explain.

my opinion after all

George

CrackHeadMel

iTrader: (2)

I have a very similar setup (cosmo re, stock intake and exhaust ports, cheapturbo t04s with a 1.0hotside hpc etc) Im in the process of swaping out my 1.0 for a .84 which my be to small, however the 1.0 was just so large for the stock ports that it really didnt spool quickenough for my likings. i wouldnt really make what im running for full boost atm (11lbs due to my *** not tuning for more yet) untill 4.5k or higher and it would drop off between shifts heavly

i guess what im gettign at is id go with a slightly smaller hotside, for more boost response on the street

ProjectD

iTrader: (15)

Interested topic. I am also curious about what some with experience have to say. I am breaking in my motor with the exact turbo decribed above (T04R). I will also be limited to 91 octane so Am curious about what others say about "safe boost" My goal is to reach 430hp on pump gas (91 octane) but the more I read about octane and safe boost the farther my goal seems. I was hoping to run about 17psi for a high boost setting and about 13-14 for low. I have mild porting on the primairies and very aggressive porting on the secondaries as well as some exhaust porting. Oh yea i only have stock primary injectors with 1600cc secondaries. I'm not trying to hi-jack this thread but i hope to hear what others have to say.

Trav

Hmm, that's interesting info -- you had a fully divided manifold too? And from what I can tell, the TO4S has a slightly smaller turbine, so it should spool a little quicker than the TO4R? Right?

Trav

So you think anything over 1 bar would be "pushing" the reliability envelope on 91? That's probably acceptable to me, I just wasn't exactly sure what I could get w/o tuning on the ragged edge...

Poweraxel

give sean @ a-spec (zero r) a call i think he could beat that price....

signofinfinity

well thats my two cents. but i guess other will agree with that suggestion.

I learnt it through fact and experience.... more then 17 is pushing it on 93....

let alone 91

Trav

Actually been trading PMs w/ Sean today already.

Trav

I guess I'm also wondering based on CrackHead's comments if a TO4S would be better suited to my application based on spool characteristics and the amount of air that TO4R is going to want?

The TO4S is about $170 cheaper...

CrackHeadMel

iTrader: (2)

it is cheaper for a to4s,, however i plan on upgrading at some point to a t04r once heavy porting takes place, i was just short on $

i do have a p-trim devided exhaust housing and some feed/greddy/something devided tubular mani

and as for the spool characteristics of a t04r compared to the 's' on the stockports, im not really in any position to answer, im assuming the powerband would be shifted up slightly, and also the 'r' is more effecient above 16lbs where from what i understand the t04s is very efficent right around 16lbs which i hope to run on my pumpgas (93 on eastcoast) with possibly alkly/water injection when the time comes

i searched this forum, and around the net for a while and from what i gatherd, a cosmo re on pumpgas with stock ports and a t04s was seeing 370-390 at the ground from all the graph's i saw, the limiting factor was the puny exhaust ports from what i read

GoodfellaFD3S

iTrader: (213)

You're braver than me if you want to run 17 psi on 91 octane, hell even 14 psi.

I highly recommend picking up a water injection kit and installing it along with the motor/turbo setup. You don't need to tune for it, you will be using it as a safety net. I run 16-17 psi on 93-94 octane with the water/meth inj coming on above 9 psi.

Here is a good thread chronicling my install, pics are on page 3:
https://www.rx7club.com/showthread.p...light=aquamist


Also, I don't think you'll like the powerband of that t04r on stock ports--I'm not surprised by Mel's results. I have a pretty heavily ported engine, and have come to the conclusion after studying many dyno charts that a t04r won't really give me anything more at pump gas levels than I have now. I think a t04s would be a better choice for you.

Trav

Yeah it seems that the TO4R might be a bit big... Realizing that it would be great for cranking up the boost at the strip, but since that's not my primary goal, I'm thinking I may be better off w/ the slightly smaller turbo that still packs plenty of "whallop"...

jacobcartmill

iTrader: (6)

as far as i know, a t04r is just a T66 wheel machined into a t04s housing... i dont see what all the hype is about.

GoodfellaFD3S

iTrader: (213)

I remember talking to surgemonster a few years ago--he was running a T-66 (t04r sized turbo) on a stock port FD. IIRC, he said that his powerband was from 5k to 7.5k. Not too fun for the street.

dubulup

ball bearing is what you want

Iwan

On my street- port FC with HKS T04R I see full boost from 4.500RPM.

Go for T04S with 0.8x housing, just what I would recommend to you.

REgards
Iwan

Trav

Honestly I have not seen a major performance increase that would justify the added cost of BB...

GoodfellaFD3S

iTrader: (213)

Well, where have you been looking? Honestly man, I think you are looking at too big of a turbo for stock ports, you'll be in lag city. If you settle for a nice 375 rwhp you'll have a nice powerband, if you really want to make 400+ you'll find it tough without maximizing the rest of your setup, to include portwork. 450 in my opinion isn't going to happen on pump gas and stock ports.

signofinfinity

^^^yep! I agree 100%

Trav

Makes sense -- obviously that's why I'm on here asking for those w/ experience, so I appreciate the feedback so far. Honestly 375 is probably more than enough for a street car... I'd probably be very happy with that. I guess I just wanted to make sure I didn't buy the turbo that just barely got me there and that as soon as I wanted to crank up the boost a bit at the strip that I couldn't. But then again, I also didn't want a lagmonster...

Zero R

iTrader: (1)

TO4R wheel is roughly 75%+ eff. At 16lbs. It wont go up from there. It just stays in that area longer would be a better way to think of it. We were running TO4R on a car here with a .82 divided housing and we were getting 15-16lbs by 35-600rpm. I think it is very hard to make a assumption on what it will do on your car compared to others. Broad assumptions ie. How y frame will be in this rpm range or x frame in this range, but other than that there are too many variables. A IC can have a huge effect on response for example.

-S-

Trav

I've not been able to find compressor maps for either the TO4R or the TO4S...

lovintha7

Great thread. I've learned alot here. I think I've decided on a T04S with .96 A/R turbine and the .70 A/R compressor...P trim, as shown on cheapturbo.com. This is with an undivided cast mani and FMIC.

This is going on a S5 TII (stock ports AFAIK) motor in an FB. I think this will get my HP numbers where I want them (350ish), but still provide boost in the 3500 rpm range.

Any thoughts on injector sizes with this setup? (12ish PSI street) I have a Haltech E8, so no worries there, and Walbro 255 pump with RRFPR.

Iwan

Go for 0.84 exhaust housing with your stock- port engine. You should see 350 when your aengine has good compression. In my oppinion 0.96 housing will be to big.

You should be fine with 4x 720cc injectors, or you can use 2x720cc and 2x 1000cc for more power.

REgards
Iwan