juggernaut1

Quick update Had the car on the dyno yesterday.......ambient temp was 43 degrees and high humidity here in Perth so it was working hard......anyway at 17 psi the Hypertune intake manifold split open. Couldn't see it (or hear it) at first but couldn't get the car to idle at less than 3000rpm so we new we had a leak after the throttle body as we checked all hoses etc. Pulled it off last night and the intake had gashed open where the idle control valve outlet is (which is underneath the manifold). Would have thought these manifolds could have handled alot more boost. Anyway will weld it up and put it back on the dyno..........with more boost.......hopefully.

Yes it would be interesting to compare the T4 1.06 to the T3 .78 GT35. IIRC Str8e180 was running the T3 .78 GT35 version on his RB26 and made nearly 400rwk's (with a few fuel issues). So you'd think the larger housing would be better still.

Not correct - the T4 is available in 1.06 as per this link. The .78 is the T3 twin scroll housing. http://forums.freshalloy.com/showthread.php?t=186058

Full-Race has T4 twin scroll ex housings to suit the GT35.

This is a response I received from Geoff at Full-Race in respect to my query on single gate vs twin gate during the development of the dual gate T4 twin scroll manifold for sr20's when I ordered my sr twin gate twin scroll manifold a little while back. Ian -- glad you like it. We have done back to back testing of the dual gate vs single gate, and the difference is significant. In fact we have to add about 18-25% more fuel from 3000-4200 rpm due to how much more air is being moved since the turbo spools up so soon. i can pull the results off the dyno computer next week (ill be on the dyno then) The comparison results were done on a T4 3582R and a T4 4088R. The use of twin gates on T/S manifolds is not about boost control - I've no doubt a decent gate will ensure that...........as can be seen from the above response its about improving pulse energy to drive the ex wheel which in turn spools up the turbo sooner. A single gate will 'leak' between the collectors as you are unable to create a perfect seal between the gate tubes. Cheers,

Because if you running a twin scroll turbo (and I'm not sure whether the 4088 is) you will have better pulse energing by keeping the ex gasses separate up to the ex wheel by having twin gates. Otherwise a single gate will allow pulse energy to "crossover" from one collector to the other prior to the ex wheel. If you look at the full-race twin scroll mani's they all have twin gates for this reason. The original twin scroll sr mani's were previously twin gate tubes merging to a single gate but are now also available in twin gate.

Also I think the Summernats dyno runs are limited to 7000 rpm - however, someone correct me here if I'm wrong.

Some of the discrepancies btn your GPS system and the track may be due to the rollout at the track. Couple of years ago Motor magazine tested a Porche at the quarter and had their VBox (GPS based testing system) strapped in the car as well. The result was that the VBox showed a slower time by around a 10th than the track timer - which was put down to the rollout. The car was already doing around 8klm an hour before the timing beams were triggered at the track compared to their VBox which starts timing from the time the car starts moving.

An excerpt I found relating to the 16th Summernats: All day Saturday and Sunday engines roared in the Horsepower Heroes Dyno Cell. On this Summernats stage, street-legal cars running pump gas are strapped into a caged dyno cell. With spectators stacked in the stands above, owners compete to find out who really has the most powerful machine. Last year everyone was shocked when a Holden ute pushed the dials well beyond the 1,000hp mark and a rotary Mazda made 500 plus ponies in the new Sport Compact class. This year, three competitors in twin turbocharged V-8 GM Commodores came into Sunday morning's final with 1,100-plus horsepower. Eddie Tassone's gold 383-ci small-block powered Commodore eventually took the trophy with1,376 horsepower.

Didn't Eddie Tassone from Active Automotive in Perth pull in the vacinity of 1200 - 1400 rwhp at the Summernats about 4 or 5 years ago using unleaded with his iron block 383 with twin turbs in his Commodore. I remember there was some fanfare about being a world record at the time on unleaded.

Actually, the full-race manifold is the heavyweight of the 2. From memory my sr 6Boost was 8kg's and my full-race mani was 10kg. The full-race does have a slightly thicker flange plate tho and provision for two gates. The full-race mani certainly does 'grow' towards my strut tower when hot.

I agree...I've had both manifolds and although I run a full-race twin gate mani on my SR at the moment - give me Kyles anyday from an internal finish point of view. I've had to spend a few hours with the die grinder on the full-race mani to tidy it up to the point where I was happy with it.

C'mon Den001 there's plenty of room in an s15 engine bay for twin gates on your full-race mani:

I know its not an exact measurement of current draw but my tacho doesn't dip at idle when the low speed comes on. Moreover, most modern cars have three thermo's and I don't see fuses popping - your 15 amp fuse may have been too low - I run 2 x 30 amp fuses on the basis the standard single thermo fan on the s15 is 30 amp. Also I guess when the speed of the fans is staged it doesnt result in a high current draw which your car may have had when pulling the fans on straight to high speed.

40 amp current draw ....strewth....throw those in the bin. Also problem with the Davies Craig fans is that they don't draw air through the entire radiator due to the lack of a proper shroud. Look at the way most manufacturers do them these days. Heres an excerpt from a Ford Forum regarding current draw of the AU falcon fans which are 2 x 12 inch fans: "There have been some queries regarding the required amperage of the alternator to run AU fans, hence I measured the current draw of the fans and got the following readings. At low speed = 3.6 Amps At high speed = 13.5 Amps" Here's a pic of the AU Falcon fan setup in my s15: I have these setup on low and high speed and controlled by the ECU - you wouldn't even know there on at low speed with low noise and negligible current draw. High speed hardly kicks in unless aircon is on.

Just found this thread link. In summary the member switched from a 4067 on his RB26 to a twin scroll 3582 and is now reportedly making 20 psi by 3500 rpm....good stuff. http://forums.freshalloy.com/showthread.php?t=189551

Yes Trent it will be interesting to see how it compares to the single scroll stuff. Can't wait to get it on a dyno, tune and run it in.

Yes its an s15. No other pics as yet.

No offense taken. I actually did consider the 3076 but Geoff Raicer from Full-Race convinced me otherwise and advised me this setup will acheive quicker lap times on a short circuit like Barbagello in Perth where I live. I seemed to get the impression from him that the slight loss in transient response wasn't worth the extra hp gain the 3076 would give. In any case, I wasn't chasing any certain power level more a case of the best transient response and area under the curve.

Street/circuit super sprints

The manifold and turbo exhaust housing is divided (i.e. twin scroll). On a SR20 this means cylinder exhaust manifold runners 1 and 4 are paired off and completely and separately to 3 and 4 right up to the exhaust wheel. Because they are paired off each pair of cylinder runners has its on gate. Whilst it is possible to use a twin gate tubes merge into a single gate - there is a cetain amount of exhaust gas pressure leakage from one gate tube to another in the exhaust manifold as it is not possible to create a perfect seal between the two gate tubes at the merge point just before entry into the single gate.

Thought I would throw up a few pics of my completed SR20 build - no dyno yet (finished at midnight last night). Interesting bits: Full-Race Twin Scroll mani with twin gates 3071 with .78 divided ex housing Hypertune Intake 1000 cc Sards Autronic Forged and Darton Sleeved Bottom End JHH Engineering Head with larger Super Tech inconel ex valves Tomie 260/260 12mm lift pro cams Pic of the gates before the dump tube went on - these actually merge back into the main exhaust.

To my knowledge none of the GT30/35's are twin scroll in their off the shelf format. ATP modifies the T3 TS GT32 ex housing to suit the 3071/76/GT35. Full-race also is putting together T4 TS footprint ex housings for the GT35. In the above test they are testing a T4 TS GT35 with a T4 TS BW - so its a valid comparison. Presumably both of these twin scroll turbo's will outspool and have better transient response than a generic single scroll GT35.

One thing I notice with the BW's is that they can generally match their Garrett counterparts at moderate boost levels but when the wick is turned up the BW's shine - presumably a function of their extended tip technology.

Here's an example of what I was talking about above regarding opening up the flange face on the FR manifolds. This particular FR manifold is for an evo and you can see that they have opened up the flange face to match to the port (admittedly evo motors have reasonably larger exhaust ports). Unfortunately, I didn't receive my manifold with this mod and had to take to it with a die grinder myself.