Episode 62: Perkins Engineering Exhaust System on Early Holden Commodore Holden or Chev Engine
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- เผยแพร่เมื่อ 7 ก.พ. 2025
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Thanks so much for sharing, showing and explaining these things. Us so called normal people would never get the chance to see this sort of stuff if it wasn’t for someone like you showing and explaining it to us. Keeping the passion alive and passed down is priceless. Thanks for your time doing these
You're welcome, cheers!
Thanks Very much for the segments .ENJOYABLE.
That's one set of nice pipes Jack. Just so LP, engineering hand drawn in pencil freehand on a piece of A4, beautiful work. Thanks for that Jack
Cheers!
Love the video. Happy to hear about the 2008-2011 systems. They were the best sounding Supercars in my opinion!
Yeah the crossover system certainly sounded good and different to the rest! Cheers!
@@perkinsengineeringThey sounded similar to a 'flat plane' V8.
Exhaust systems are one of the most interesting parts of a car!
For sure! Cheers!!
ALWAYS something interesting to find out about these cars and how thing were done at Perkins Engineering. Look forward to every episode. Thanks Jack.
Many thanks!
Appreciate you taking the time to answer our questions!
You’re welcome! Cheers!
Thats one of my fav race car of all time love it
Cheers!
Great insight Jack, many thanks for taking time to share this.
Car looks mint mate 👌
Glad you enjoyed it, Cheers!!
Good job jack🍻👍
@@robm4288 cheers!!
Thanks Jack, im one of the hounds that has been asking about the cross over headers. Glad you could finally bring us something to quenched our thirst. Was as much effort put into making the primaries the same length as in the tri y system? Or was it just accepted that two runners from either bank were going to be longer? Cheers mate! Keep up the good work and good luck for Bathurst.
I think it's always an effort but I never personally made any so I'm not exactly sure. I think from a performance point of view you have to get them bloody close! Cheers
thanks jack , long time between drinks that one , & exhausting to watch .
Hahaha Cheers!!
I find it interesting how the pulse entering the exhaust changes the note so much. i also follow an American (KSR) and he built an 8 into 1 (Exhaust exits over the engine but its a burnout car) with the pipes following the firing order (pipes enter the collector in the firing order)its sounds like a tractor at idle but at revs it screams like an F1 car
Very interesting isn't it. Thanks for watching, Cheers!!
Nice, golf ball measurements
Scientific!
Jack have you done an episode on the rear axles and diff and housing?
I heard those were made from exotic materials to save weight.
Check out Episode 16 and 18. We didn't make our diffs or axles out of anything exotic!! Cheers!
Hey Jack. Love your work 👍
Many thanks, Cheers!
Once again awesome thanks
Cheers!!
Hi Jack, very informative, just wondering with the two mufflers are they straight through with meshing or is there a pattern inside that creates that sound? Can you explain how you designed the internals of the two mufflers please.
Hard to explain without a visual, they have a perforated tube through the centre and the outside of that section to the stainless walls is packed with steel wool. This design in principal last a long time, sometimes there was an auger or spiral section in there possibly to make it quieter. Cheers
Studs or bolts on the headers to cyl/head ? And probably clearance there was important as well. That Jack Daniels car sounded awesome. Cheers.
We always used bolts. Cheers!
Very Good Jack⚡️⚡️🐝👍🇦🇺
Cheers!!
Great stuff
Cheers!!
Interesting they still use imperial measurements! See you at Calder soon!
Not sure exhaust tube materials have moved to metric yet! Cheers!
Yeah, it's basically impossible to get metric exhaust materials in Australia! Most production cars apart from American ones use metric exhausts though -- 50mm, 55mm (2.16"), 60mm (2.36"), 65mm (slightly bigger than 2.5"), 70mm (=2.75"), 80mm (3.14") etc. I was surprised to see that the VE Commodore was metric - dual 60mm going into dual 55mm at the rear mufflers, I thought it would be imperial!
Another awesome video Jack , yes alot would think a exhaust moving around like that would crack , I'm surprised your Dad didn't use vw bump stops on exhaust mounts like hes famous shifter knob.
Any chance of buying a LP vw shifter knob for a t5 ??
Cheers Jack
Haha some of the exhausts used rubber mounts! Cheers!!
I want the specs on those 304 heads. Holden did a great job on those as well as the 'street' mapping. Memcal chips drove me insane.
This car is an 18 degree Chev!
cool mate
Cheers!
Great video Jack, as always! Quick question - is the engine solid mounted or rubber mounted, on these cars? Edit: Gearbox crossmember suggests rubber mounted?
The engine mounts from the engine block to engine cross member are on a solid rubber mount from McKay, they could be a version of standard GM actually. Gearbox is also on a rubber mount to the gearbox cross member. Cheers!
Hi Jack. Thanks for another informative video. As usual I do have a question, what is the reason for not having each bank its own exhaust and having a muffler on each side of the car?
Oh and I saw on Facebook that Perkins #2 is being loaned and on display at the Motor Racing Museum at Bathurst.
There's probably more than one reason, the reason's I'm aware of are clearance under the drivers seat and then subsequent temperatures under the driver.
The floor sections get cut out on the passenger side so mufflers can fit under there and not scrape along the race track.
Then you can achieve the same thing going out one side in terms of power out put etc. Cars would be somewhat quieter at the race track if they came out each side, because standing next to the track you would only hear 4 cylinders instead of 8....
@@perkinsengineering Thanks Jack for your comprehensive reply.
Nice vid
How much work was done on designing that exhaust for the power curve you wanted versus just getting it to fit?
Dyno time?
Did dimensions change for different tracks?
Always limited by funding! Could try different systems but it all cost money. In-house fabrication makes this cheaper because wages are effectively paid for so the cost becomes the materials. Could easily try different size tubes and stepped headers and "easy" stuff but couldn't really come up with a "winged keel" if that makes sense. Always tried on the dyno first to measure gains or losses. I don't believe there was ever enough resources to have circuit specific systems. One year at Bathurst they pulled the mufflers out for Qualifying or the Shootout or both, so loud, too loud, know as a megaphone in PE, but it was better! Cheers!
How did you mount the starter to the Chev block on the LHS? Would love to see some details on this...!!
These days you can buy the components to do so. I suspect many do not take or give oil to the filter pad. So you can fit the starter there giving room for the steering. Always a problem with RHD GM engines
I believe we just machined threads into the block and make a mounting plate and bolt it up!
Back in the 90's we just made it all
@@perkinsengineering I guess that depends on the block you guys used.
OEM SBC blocks had the oil filter on the LHS, so that needed to be blocked off and remote mounted.
Either way, I love the innovation from back in the day... just amazing stuff.
The further the exhaust gas travels, the colder it gets, and shrinks in volume. Why do the rear pipes get larger?
@@Hazzy238 for performance. Sounds better also
Do you run a cover over the Flywheel/Starter Ring gear?
@@riverracer negative
Needs a Racecam in it if you want it period correct... ;)
Haha yes that's correct and we may or may not have that!
@@perkinsengineering And the Ch7 helicopter to down load those pics!
What's the advantage of the 8(-4)-2-1 compared to the dual systems with an X-pipe? I'm curious if the X-pipe does the same thing as joining the banks (at an equal length) or if it has a different effect? 🤔
Good question. Ultimately there's a packaging issue in terms of what you can and can't do with the exhaust system. If you just built a system for a dyno and didn't have to worry about chassis rails, steering racks, starter motors etc. etc. then it would be interesting to know what the ultimate system would be. My experience (limited) with exhaust systems is it's always a trade off between torque and horsepower.
I think the tri-y setup enables equal length pipes without the packaging issues associated with 4-1 headers. Interesting how they still chased equalised length right down to the join at the muffler.
Not sure of the science behind the linked crossover system.
Crossover system splits the exhaust pulses evenly, which are otherwise split unevenly in the case of tri-y or 4 into one (due to the firing order of the cylinders). Check out gt40 exhaust system you will understand.
Correct, works like a flat plane crank I believe
Effectively two of the header pipes are crossed over from each side to join the other side, increases volume in the system and creates evenly spaced pulse, hence the noise variation. Improves the engine torque and some times the tunability.
Cams and v8 supasuc loved chev dollars, look where it ended
Cheers!!
Metric or imperial golf balls?
Having recently watched a social media video from LIV golf where players had to guess/tell the OD on a golf ball, the correct answer is imperial. I think the correct answer was 1.64". Scary that one professional player actually said 12 centremeters!?!?!?!
Not sure if this has been asked before but the '91 mobil VN Group A cars seemed like the last of the truly loud & meaty sounding touring cars, LPs VL in 92 and the bathurst winning 93 VP were noticeably quieter to me.. is it just me who thinks they're a bit subdued in the decibels department or were they made quieter deliberately?
The exhaust systems were very similar. The header pipes were a little different under "Group A" rules but I believe the mufflers were basically the same. Could be more related to the RPM of the Engine and some induction differences between the twin throttle and slide manifold. In 1991 they revved the engine to around 8500, maybe even higher in qualifying if it would cop it. That sounds much different than 7400-7500 in 1993. Cheers!
Yes, there were Decibel limits in this period of racing. One particular race meeting we had to stuff Chicken wire in the Glen Seton Racing Falcon's exhaust, as it was just above the limit..
I thought the 94 car ran a 5ltr Holden Motor.
Negative, first year of Chev power for us! Cheers!!
FIRST!
does your mommy know your online...?
@@dmystify1381 I am his mother and yes I know he's online. Don't talk to me or my son ever again
Cheers!
Amost got a problem Jack...... the projects almost finished which means you need to find another....😅
Haha not wrong there!!! Cheers!!
1 7/8 is a very big primary pipe on a 5litre. Too big! TriY exhausts are for grandpas car to tow a caravan. Or engines without enough room for proper pipes. In my case LC Torana with a Chev and 1.3/4 primaries.
Nascar have long proven the long pipe headers and X pipe works on serious engines. Not 10-1 302s!
Seemed to work ok for us! Cheers!
How many touring car races has your LC chebby won!?
Nascar use x pipe for a different specific reason.
C.LOWN
Nascar uses "try Y's" bud. Do some research.
Blows my mind that people will pay thousands for titanium exhaust on a 2 ton road car
Who's done that?
@@perkinsengineering Audi RS6 has it as an option I think, akrapovic make a titanium exhaust for it though too saves 10kg...
@vokstar it would be for looks and sound. Very raspy and tinny sound from titanium
@@juddy953 All you can see is the tip though, so looks I think is dubious. If it is about sound then just get a tubular stainless fabricated exhaust. What I think it is about is down the pub... oh yeah my car has a titanium exhaust don't you know, cost me thousands! To each their own though.
I absolutely loved that these cars were essentially very hot road/race cars. As the cars became better and better and more and more pure race car, I lost more and more interest! Now it's at the point where the governing body completely dictates the recipe of a car.
Cheers!!
Algorithm steered me here, listened to a lack of content apology and a shill for the new merch (clear on his priorities). Well recon with a comment, I can be done with this channel all within 3min. Bye
Thanks for the feedback and have a great day! Cheers!!
@perkinsengineering hopefully they brought a hat along with bothering to leave a comment.