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Hey Brettus, out of curiosity...why did you go with a T3 flange instead of a V-Band?
I tried the V-band first but there were a few things I didn't like about it
* You need to clock the turbo on the v-band to get the right position , with T3 it can only go in one position so it can't be wrong !
* Needs to have the V band fitting welded to the manifold and I needed to grind it down before doing that ..... T3 just needed machining
* Couldn't get the turbo as close to the block as I could with the T3
* T3 just works better with the rectangular shape of the manifold
That plus there is zero flow advantage from either the v-band or T4................................ IMO
just pointing out though; you can now get a 0.85 A/R divided T4 manifold for the Garrett G30 through Pulsar. On an REW that might zing pretty good.
or my future Renesis manifold … what the divided T4 does provide is a better 90° flow transition for a more compact manifold, coupled with a radiused divided flange inlet as I’ve done here (needs final hand smoothing, though the radius is more equidistant than it appears). The benefit comes into play at higher power levels with less emap imo:
divided T4, also have same for div T3
which I’m pretty close to starting fabrication of the RX8-REW manifold soon. it will have a much shorter, more direct, equal length flow path than any of the RX7 manifolds. Because straight out of the engine there’s a bit more extension space in the RX8 chassis, but the RX7 chassis has more room once the turbo is angled upward rather than straight out to the side.
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except there’s more involved than that, especially when working with space limitations and then changing flow direction within those limitations.
so it’s not as straightforward as assessing just port area as you’re making it out to be. Yet without having a specific example in front of you I recognize that it’s hard to get the point across. So I don’t want us to beat it in the ground as was done in the past. Also knowing that results talk and theory will walk. So let’s just leave it until then.
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That's why I called it "crude" .... Because I realise there is more to it than just cross sectional area comparisons. What I did above still has relevance though.
Basically ........ what you are now saying about the better transition was my argument back when we last hashed this over.
I think each situation needs to be assessed on all factors and yes, in some situations , where there is a choice between T3 and T4, there will be a big advantage from the better transition in going to a T4. In my case , not so much.
Thought I would start this thread for anyone thinking of getting this setup so they can order components and hit the ground running. The component list is also a good start point for any turbo setup IMO.
I've spent a number of years trying various products and fine tuning my system to get the best possible result so this list can save you a lot of effort.
Brettspeed manifold pictured below
I'll start with a list of recommended products etc . 1/Turbo : Garrett G30-660 . This is basically the ONLY turbo that I know will fit the above manifold properly.
Turbine:
AR 0.83 T3 in 'V' band out for mild setup with aftermarket catback exhaust for fastest possible spool.
AR 1.01 T3 in 'V' band out for any setup involving custom made 3" plus freeflow exhaust system for higher sustained power and superior boost control
Note : there are Chinese knockoff turbos from Pulsar and others. I personally would not recommend any of these unless the vehicle is 100% street duty and you don’t mind taking a risk on performance and/or durability.
2Wastegate : Tial MVR 44mm
Possible alternate : Turbosmart GenV Hypergate45
Wastegate pipe : 45mm OD pipe with bellows and v bands at each end connecting to downpipe or dumping to atmosphere (warning – it sounds terrible like that).
3/Blowoff Valve : Synapse Synchronic diverter valve (can be purchased with a weld flange suitable for welding to aluminium pipe.)This valve allows for easy recirculation which is essential in a MAF based tuning scenario. https://www.vividracing.com/synapse-...150705244.html
I recommend this IC because it will comfortably handle flow in the 300-400whp (rotary) range and if fitted as high as possible, will allow sufficient air to pass under it such that radiator performance is not unduly affected. The in/out tubes are in the center which works well with the rx8 radiator plastic cowl etc while avoiding the in/out pipes from blocking air flow to the radiator. Very important! Added bonus : Centre in/out tubes are more efficient thus improving performance over other ICs of the same size.
5/Injectors :
93(98Ron) octane Pump gas (Max. recommended 9psi 315whp) :S1 6 port yellow/blue/blue 3456cc @ 58psi total
E30 (Max recommended 13psi 385whp) : S1 6 port yellow/Uncapped yellow/uncapped yellow 4350cc @ 58psi total
E30 - better spray pattern stock injectors for around 350whp on E30 : S1 6 port .... green/brown/brown 3600cc@58psi total
6/ S1 Fuel pump : For max on pump gas Deutchwerks DW200
7/Spark plugs for max on pump gas : NGK R7420-9s with extra washer on trailing
For max on E30 or track duty : NGK R7420-10s with extra washer on trailing
Always fit good quality after market leads as the stock leads are crap and will cause premature coil failure as they deteriorate.
9/ MAF setup for use with stock ECU : 31/2” OD aluminium tube with honeycomb straightener before maf sensor. Minimum 200mm long with sensor placed equidistant from either end. Note: the AEM maf tube works great as it has the bend you need at one end plus intlets for jet air, omp and oil fill vent. Steel mesh can also work but honeycomb straightener is far superior.
If you don't have the AEM ..this is a great starting point : Treadstone Performance Inc., Turbo Kits, Intercoolers, Turbo Manifolds, Silicone Hose
Note: Please don’t ask me to tune your setup if it doesn’t meet these maf specs.
10/Intake :
Cold side : After maf tube reduce diameter to 3” and carry that through to turbo inlet
Hot side : 90 degree silicone elbow 2” reducing to 21/4” straight off turbo (note leg on 2” side will need to be cut down to minimum length) increasing to 21/2” after steering column then 3” into IC. From IC to throttle either 21/2” or 3” . LHD cars may work with 21/2" straight off turbo but not 100% sure that will fit.
11/Exhaust :
For 300whp and below : 21/2” stock (gutted cat) or free flow aftermarket . If you have to run a cat - high flow cat only plus I would recommend that the WG gases bypass the cat altogether for best performance and longevity of cat.
For low to mid 300s : 3” free flow
For high 300s to 400: 3” free flow with separate 13/4” pipe for wastegate (or use a screamer pipe if you don’t mind your ears bleeding – not a pleasant noise)
have you done a Matchbot plot for where it’s operating now at the lower boost level?
No ...but I did make quite a realisation the other day ..... after realising I had some boost creep ...that also meant my EMAP/IMAP was actually better than I thought . This turbo is so darn efficient !
Some good news .... this latest setup is having zero boost creep issue. This setup is what I'd call 'relatively' free flow and is representative of what most people will do. The catback is a 3" Pettit Racing setup but it does have a 21/2" resonated midpipe which may be creating some backpressure. At the moment boost is dropping to 4psi by 8000 from a high of 6.5 on a 7psi spring. He is also running the 45mm TS hypergate V vs the 44mmTial which could be helping!
He is fitting a bigger 8psi spring which he says helped his previous system hold boost (same WG) so hopefully it will do the same on this setup.
But I'm very happy to see that boost can be held so low given that my setup struggles to stay under 10psi at high rpm.
yeah, just adding backpressure on the turbine outlet is going to help bias flow/pressure to the WG and provide better control. Some people backpressure the whole system by doing it farther downstream (common technique on RX7Club), but imo by doing it before the WG merge the overall backpressure is lower and the system should perform better overall. So using a smaller diameter downpipe, but then expanding it to a larger diameter at the WG merge to handle the total merged flow is the better way to address it imo.
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He is fitting a bigger 8psi spring which he says helped his previous system hold boost (same WG) so hopefully it will do the same on this setup.
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That fixed the issue ...now running 10psi but rev limited to 7700 due to maxing out the upgraded S2 fuel pump.
He is very happy - better spool than his old Greddy setup and more power than his old top mount setup ....
10-23-2022, 01:40 AM
How can I get your manifold?
