Mazda Rotary Club

Hi Guys a bit of background first. :D
 
After my trip to Cadwell earlier this year I was very satified with my car apart from the underbonnet temps, water temps stayed a breezy 98c even after an 8 lap stint. Air temps though we\'re 90c which is frankly rubbish.
 
So to get a bit more power, reliablity and cooler air temps I\'ve decied a turbo upgrade is required. My shortlist was, GT35R (AKA GT35/40), TD06-25g, Apexi RX6b (the larger of the two), TD07-25g.
 
As I\'m sure someone will ask I\'m after ~420hp give or take hopefully at a bar or less. My main concerns are response and smooth power delievery, with peak power as high up the revs as possible.
 
So my question is who out there has a GT35R, what\'s it like, what sort of power are you making at what pressures and just general impressions or info?
 
I\'ve noticed a few places do various housings front and rear are there any optimal setups? Is there any point in Anti-Surge housings and what are the benefits of the T4 footprint divided housing?

wooh mate!! stop right there!!

90c inlet temps....are you sure thats not a typo......if its true you need to forget all about turbos for the moment and sort out your inlet temps.

first thing you need to do is get a better intercooler setup, either front mount or v mount, when you have got your inlet temps lower than 40c on boost then we can get to messing about with turbos.

changing turbos wont suddenly make your inlet temps drop by 50c.

im guessing your running a stock intercooler?

the gt35 of some kind is a great turbo.  Max used one for years in his FD and regurlarly managed sub 8 minute laps at the ring.  It will spool well but still hold out well for reasonable power.

But,  as above,  90degree inlet temps is shocking.  Post a picture of your engine bay it may give an idea as to why

Dont forget.  That little turbo upgrade will also need an ecu if you dont have one,  fueling if you dont have it and intercooling plus possibly exhaust to get the best out of it.  Just make sure you budget for it all.

Well, I should have been able to give you a response by now, but due to a small water evactuation issue, instead of having a complete, mapped  GT35r\'d car, I now have a useless driveway ornament, an engine in my garden, and a new set of coolant seals in customs.

As a result, I can only relay what I learnt in my research and run in.

I happily admit I knew, and still know, absolutely bugger all about turbos. So I just read and read and read, unfortunately most of which was on american forums, so I spoke to a whole bunch of people in the UK scene, and a fair few tuners. The upshot was that if I wanted medium power, and max response, the GT35r should suit perfectly. Basic facts I gleaned from cars run/mapped in the UK were:
- 1 bar by circa 3.7k (obviously, port dependant)
- Power outputs of 400-450 atf, depending on mapper and variation used
- super quick response, not far off twins.
- a power graph of a uk car (can\'t find it at the mo) showed that at about 3.5k, a GT35r equipped car made roughly the same power and torque as my car on twins - from this point on it just made more and more, and the torque basically hit a lovely flat plateau and held it there, rather than dropping off significantly like it did with my twins.
- vital to the output and response is the porting - again, something I know nothing about. So I basically gave my plates and housings to Era de Clerke at Oldone racing, who from what I\'ve seen, is pretty much one of the best guys out there. His results speak volumes.

I\'ve gone with the T4 divided 1.06 rear. As response and spool was my ultimate goal, I spent a long time considering if the 0.86 would be a better choice - however, everyone I spoke to advised me that yeah, I\'d gain spool about 500rpm sooner, but the turbo would choke at higher revs, so ultimately I\'d lose circa 1000-1250rpms of power band.
The T4 footprint was pretty much dictated by the manifodl I run (ASE custom)
However, I really wanted the divided housing, as they seem to drastically improve spool.

I\'ve also gone for a ported shroud, as the last thing I wanted were issues with surge. In addition, I also wanted the option of running without a BOV. And, If I\'m really honest, I love the mental sound they make as they rip the air apart.

Like I say, unfortunately I haven\'t driven it in anger yet. I have done 1000 miles on it on run in, and started giving it boost later on as part of this. What I will say is that the response was amazing - run in was very hard, as it spooled so fast it was near on imossible to stay out of boost! it just wanted to take off.

With any luck I should have it back together in the next month or so, then mapped, and I can report back. I\'m hoping for 400-425 or so at the fly. It all depends really. I\'ve tried to be as compehensive as I can with my spec so I may acheive better.
It really isn\'t cheap to do it properly though :(

Brief noise clip from about 43 seconds here:

:)

That\'s part throttle, limiting to 0.3 bar with my right foot, unmapped - it still felt amazing to me :D

Quote from: turbotoaster;713259wooh mate!! stop right there!!
 
90c inlet temps....are you sure thats not a typo......if its true you need to forget all about turbos for the moment and sort out your inlet temps.
 
first thing you need to do is get a better intercooler setup, either front mount or v mount, when you have got your inlet temps lower than 40c on boost then we can get to messing about with turbos.
 
changing turbos wont suddenly make your inlet temps drop by 50c.
 
im guessing your running a stock intercooler?

Just a sec before everyone gets carried away with inlet temps!
 
On the road I\'m lucky ever to surpass 50c even after a long hammer round the peaks. I\'m running a Blitz SMIC and a \'99 spec nose which should off much better than stock cooling.
 
On that day I did about 45-50 laps of Cadwell often rammed up someones backside where there is zero airflow. The car had been sat in the pits with the bonnet open, but when you\'re only leaving it half an hour between runs and running a bar on stock twins. the temp was only dropping to about 65c before I was back out giving passeneger rides. I must also iterate that 90c was my peak about 4 inches from the back of a red Focus ST for 5 laps until he eventually shifted, regular temps were ~70c.
 
The temps are those indicated on the power FC at cruise on the motorway ~80mph I see 79 water and 25 air.

Quote from: antnicuk;713277Dont forget. That little turbo upgrade will also need an ecu if you dont have one, fueling if you dont have it and intercooling plus possibly exhaust to get the best out of it. Just make sure you budget for it all.

All that is sorted already running AFPR, 1680cc secondaries, uprated fuel rail, FEED Sonic SR System with Sonic PP decat, and PowerFC there are a few other bits and bobs but the car is ready for it.

even so, 70c inlet temps are still way to high, get rid of that smic and get either a front mount or a v mount.
 
if your never going on track again then leave it in, but if your planning on going back on a track day then change your cooler setup
 
after once thats all sorted you can change turbos

Comparison (closest I can find)

My old car on twins
(http://i140.photobucket.com/albums/r30/Simon_r_hill/FDProject/PostMapping/IMG_1608.jpg)

0.82 35/40
(http://i632.photobucket.com/albums/uu44/davyv/3.jpg)

So at roughly 3.5k they are about the same, then the 35/40 kicks and holds, whereas the twins tail off.
Granted, that\'s the 0.82 - the 1.06 is a bit laggier, but not by much at all, and holds much better and produces more top end (the owner of the 35/40 car said another 20bhp and a much harder pull)

Same RR, same mapper.

I\'m wondering if I\'ve been looking at the peak hold temperature rather than the running temp..... :3Confused as obviously when I\'m sat in the pit lane exit with no air flow inlet temps are going to ramp and when I start the car in the pits it\'s been sat warming the air up for a while.
 
I\'ll take it out for a smash round as soon as it\'s dry and have a look at the running temp.
 
But anyway not to worry I\'m not buying it this moment I just wanted opinions of what this setup was like, though I do appreciate the car diagnostic.... :Giggle
 
SiH thanks for the pics and sorry to hear about your lawn ornament just be glad you have an FD and not an MA70 Supra, it\'s almost permanent.

90c is nuts, i\'d imagine you\'d be seriously down on power with inlet temps that high? ditch the SMIC and go for a V-Mount or FMIC. if you\'re going from twins to a single i imagine you\'d be running more boost? more boost = hotter air.

Quote from: jackaleks;713366if you\'re going from twins to a single i imagine you\'d be running more boost? more boost = hotter air.

I\'ll be running the same or less boost in a larger volume = cooler air
 
Everyone seems to go on about V-mounts I know they are the ultimate setup but V-Mounts are only dead necessary in drift cars where there crap airflow through the front as you\'re pointing the wrong way half the time. No other car than the FD seems to have them as a popular choice as theres just no space to do it.
 
Let me get the car out and sapnk it a bit as I said above I might be getting confused and remembering peak temps from well over a month ago

the reason people go for them is it allows air to get to both the rad and the cooler.
 
its got nothing to do with them drifting, all the top time attack cars in japan run vmounts.
 
You can get colder inlet temps with a front mount but then you risk high water temps because of blocking the rad.
 
for the road id suggest front mount, for track id say v mount.
 
You need to monitor your power fc while on boost, not look at the peak readings.
 
a small smic like what you have got will struggle with a big turbo.
 
Also you said you were gonna take it for a thrash, but earlier on you said you only get up 50c inlet temps(bit high) on the road anyway, so unless you take it back to a track you cant properly check anyway.
 
my advice and im guessing everyone on here will agree is get a different cooler setup before you go back on track because you risk damaging your engine

I am liable to occassional exaggeration/confusion/or downright stupidity from time to time when it comes to remembering anything before yesterday!
 
Look guys I\'m loving the advice, but could we please get this thread back on topic, no unpleasentness intended! :)

well if your after a turbo then we need to know how much power you want as that will dictate the turbo thats suitable for you

As I said I\'m aiming for a responsive ~420fwhp give or take I don\'t mind being on boost late in the revs as long as I have an excellent top end so with a shorter diff I can get as much mechanical advantage as possible (long term) I was thinking of a GT35r with a T4 1.06 a/r hotside.
 
At the weekends I like a drive out in the peaks so I need something thats not going to give lump[y power delievery, just nice flat torque so I can get a nice linear powercurve.

then the gt35 sounds perfect for you then, as it will be having a walk in the park at that power.
 
should give you a nice power range of 3500-7500rpm which is plenty for the road, if you want to rev it harder then maybe a gt4088 but to be fair i think that might be a bit big for your aims

Are any of the turbos I metioned in my first post comparable in terms of that type of performance. I love my JDM as much as the next man! :D

the rx6 will do 400bhp at 0.9-1bar of boost but its got a very small rear housing so i wouldnt suggest it.

i think karl tate is running a td07 and its 440bhp so thats an option.

but to be fair your best just getting a non bb gt35 or borg warner s360 if your looking for that power. its half the price of a gt35r and that way if something were to happen to your turbo they are cheap to fix instead of having to replace the bb cartlidge which costs nearly as much as a new turbo.

good thread :)
where\'s the best place to buy a non bb gt35?

now thats a fun question!!

I thought since you can get a journal bearing of most turbos you would be able to get that, but checking with garrett it seems you cant.

The reason being is that they are selling the T series turbos fine, the closest one to that is the T04R which is £650, you can get a gt35r for £950 but id always be worried about cooking the bearings in them.

Do you have any porting as that will effect how much power you get and spool time, as if your porting is decent you could go to a gt4088, have similar spool and make more power.

Ed is pretty good when it comes to masterpower turbos and greddy turbos and i know a fair bit about borg warner.

does a brand bother you at all or you just after the best bang for your buck as such

the closest equivalent to a gt35r non bb is a to4s/t60