Project manifold !
27 June 2014, 11:03 AM
#1
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Project manifold !
Having a bit of time to kill recently and some friends who are quite handy at fabrication we hatched a plan to improve the intake side of the Enginetuner 99 Impreza.
I had 2 spare 99 manifolds laying about and handed them to my good friend Matt a local engineer, who immediately set about making a jig to hold the manifold at the right width.
The middle section was then removed and thrown away from both manifolds and the longer straighter sections of both manifolds were re-fitted to the jig.
Now we had a decision to make. Build a custom box inlet similar to the Forsa version for Newage cars.
https://www.google.co.uk/search?q=fo...24%3B800%3B600
Or something a bit different.
Matt being a resourceful kind of guy happened on his travels one day to find an old dive cylinder which he decided could be the perfect start.
Having cut it open and to the approximate length we had in mind.
He then proceeded to machine it out as it was over 15mm thick, ok for it's original use but a bit thick for what we needed.
It was then offered up to the runners and marked for cutting.
He'd also started to make the front end ready for the throttle body to be fitted to.
It was then handed to another good friend of mine Julian for some of the welding.
More on this later !
I had 2 spare 99 manifolds laying about and handed them to my good friend Matt a local engineer, who immediately set about making a jig to hold the manifold at the right width.
The middle section was then removed and thrown away from both manifolds and the longer straighter sections of both manifolds were re-fitted to the jig.
Now we had a decision to make. Build a custom box inlet similar to the Forsa version for Newage cars.
https://www.google.co.uk/search?q=fo...24%3B800%3B600
Or something a bit different.
Matt being a resourceful kind of guy happened on his travels one day to find an old dive cylinder which he decided could be the perfect start.
Having cut it open and to the approximate length we had in mind.
He then proceeded to machine it out as it was over 15mm thick, ok for it's original use but a bit thick for what we needed.
It was then offered up to the runners and marked for cutting.
He'd also started to make the front end ready for the throttle body to be fitted to.
It was then handed to another good friend of mine Julian for some of the welding.
Last edited by MartynJ; 28 June 2014 at 11:50 AM.
27 June 2014, 11:25 AM
#2
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Part 2
Back from the first part of welding any unwanted lugs were removed and reqd ones re-made and welded back on in the right places. Vac take offs were drilled and tapped and a boss for 2 extra injectors we'd made earlier in the year was welded on along with the machined throttle body plate.
Matt then whipped it over for trial fitting before we decided on a finish for it.
I had thought about going carbon for a finish but we decided it can look tacky and went instead for something basic.
Fuel rails all fitted and time to pop it back on the car.
More again later !
Back from the first part of welding any unwanted lugs were removed and reqd ones re-made and welded back on in the right places. Vac take offs were drilled and tapped and a boss for 2 extra injectors we'd made earlier in the year was welded on along with the machined throttle body plate.
Matt then whipped it over for trial fitting before we decided on a finish for it.
I had thought about going carbon for a finish but we decided it can look tacky and went instead for something basic.
Fuel rails all fitted and time to pop it back on the car.
More again later !
Last edited by MartynJ; 28 June 2014 at 11:51 AM.
27 June 2014, 12:07 PM
#4
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All fitted and wired up (Except the extra injectors as we're not quite ready for that yet 
Coolant system bled, levels all checked and we're ready for the dyno.
Straight Tesco 99 was the fuel of choice to compare earlier figures from the car and to try and crack 600bhp on pump fuel.
Back again soon !
Coolant system bled, levels all checked and we're ready for the dyno.
Straight Tesco 99 was the fuel of choice to compare earlier figures from the car and to try and crack 600bhp on pump fuel.
Back again soon !
Last edited by MartynJ; 28 June 2014 at 11:52 AM.
27 June 2014, 02:44 PM
#5
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Part 3 (Mapping)
So car on dyno, all warmed up and part throttle stuff done and the car is already showing signs of improvement in it's VE as it's taking a fair bit more fuel especially higher up the rev range.
A quick run at actuator pressure confirms this, Red lines prior to manifold, Blue lines after manifold.
Pleased with initial progress, onwards and upwards gently increasing boost and tickling the timing and fueling as we go.
We cracked it ! 600+ on pump fuel and have lost nothing compared to the previous set up, it spools as well as it did previously and makes only 3hp less than it used to on race fuel at less boost too.
Now to try the larger Blouch turbo I have sat here waiting for testing and then on to race fuel mapping and setting the nitrous back up.
700+ ?
I hope so
So car on dyno, all warmed up and part throttle stuff done and the car is already showing signs of improvement in it's VE as it's taking a fair bit more fuel especially higher up the rev range.
A quick run at actuator pressure confirms this, Red lines prior to manifold, Blue lines after manifold.
Pleased with initial progress, onwards and upwards gently increasing boost and tickling the timing and fueling as we go.
We cracked it ! 600+ on pump fuel and have lost nothing compared to the previous set up, it spools as well as it did previously and makes only 3hp less than it used to on race fuel at less boost too.
Now to try the larger Blouch turbo I have sat here waiting for testing and then on to race fuel mapping and setting the nitrous back up.
700+ ?
I hope so
Last edited by MartynJ; 28 June 2014 at 11:55 AM.
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27 June 2014, 09:31 PM
#9
So specialist tuners spend hours designing the internals of inlets with tapering lengths and internal trumpets and all they needed to do was use a tube.
Be interested to see a back to back against something like the cosworth manifold.
What's the science behind the improvement? There's a restriction with the size of the manifold after the throttle body in relation to it's inability to feed all runners efficiently?
Be interested to see a back to back against something like the cosworth manifold.
What's the science behind the improvement? There's a restriction with the size of the manifold after the throttle body in relation to it's inability to feed all runners efficiently?
27 June 2014, 11:57 PM
#10
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Thread Starter
So specialist tuners spend hours designing the internals of inlets with tapering lengths and internal trumpets and all they needed to do was use a tube.
Be interested to see a back to back against something like the cosworth manifold.
What's the science behind the improvement? There's a restriction with the size of the manifold after the throttle body in relation to it's inability to feed all runners efficiently?
Be interested to see a back to back against something like the cosworth manifold.
What's the science behind the improvement? There's a restriction with the size of the manifold after the throttle body in relation to it's inability to feed all runners efficiently?
I'd had a look at what else was available and nothing retained sidefeed injectors which would mean a complete fuel system redesign too. I have Deatschwerks 1100cc sidefeeds which weren't cheap and work very well so I didn't fancy swapping to topfeeds.
We had no idea whether it was going to work and sang the Doctor Pepper song many times.
Thankfully it seems to have worked a treat.
28 June 2014, 12:00 AM
#11
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As a basic rule of thumb by the way if you change inlet, exhaust, turbo etc and see more power for less boost you're on to a winner !
28 June 2014, 07:18 AM
#12
28 June 2014, 05:22 PM
#14
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No problem. We're now just over half way through fitting the larger turbo so more updates to come next week !
28 July 2014, 02:06 PM
#15
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Larger turbo fitted and ran on Tesco 99 again and on the larger exhaust housing it was a bit of a flop. Swapped the exhaust housing over to a .82 and it made exactly the same as the GTX turbo 609.9bhp.
I've since swapped the fuel over to C85 racing ethanol and tweaked the map to suit and this was the result.
Flywheel power and torque
WHP and boost
And some pics of the car wearing her new boots.
I've since swapped the fuel over to C85 racing ethanol and tweaked the map to suit and this was the result.
Flywheel power and torque
WHP and boost
And some pics of the car wearing her new boots.
28 July 2014, 04:08 PM
#16
Sorry but I can't help looking at that and thinking what a bag of **** it looks like especially with that front bumper.
I want it de-stickered with road tyres please .
I can only imagine the looks people in exotica have on their faces as it murders them.
Last edited by ditchmyster; 28 July 2014 at 04:09 PM.
28 July 2014, 04:34 PM
#17
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what is the real science behind the improvements? Why is there so much improvement over the old manifold?
is it just because you fitted the sidefeed injectors, not really the manifold itself?
28 July 2014, 04:58 PM
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28 July 2014, 08:34 PM
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Looking good Martyn !!
When are you next out ,you coming up to shaky sometime.
Not been out myself this year,have been waiting for modena gearbox parts from Australia for the last few months
.
I'm swapping to hoosiers as well
.
Hope to run end september or mid October
When are you next out ,you coming up to shaky sometime.
Not been out myself this year,have been waiting for modena gearbox parts from Australia for the last few months
.I'm swapping to hoosiers as well
.Hope to run end september or mid October
28 July 2014, 10:14 PM
#20
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I've softened up the rear end with some UK sport shocks and springs to get her to squat and the Hoosiers should grip a bit better than the 888s.
Taller rolling radius too 😊
06 August 2014, 09:02 AM
#22
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Well the weather threw a curve ball at the weekend making me doubt whether the drag radials were the right tyres for the occasion so back on with the R888s.
Got there nice and early and after sign on and scrutineering started with a few low boost runs. Car felt great on the C85 running very clean and straight down into the very low 11s at just 1.4 bar.
Time to raise the stakes.
High boost map selected and pull up to the line, she knocks out a 1.71 60ft going on to a 10.62 1/4 with a 137mph terminal, a new PB but still far shy of where it needs to be.
Now looking at dates for RWYB events at Shakespeare County for a proper shake down.
Got there nice and early and after sign on and scrutineering started with a few low boost runs. Car felt great on the C85 running very clean and straight down into the very low 11s at just 1.4 bar.
Time to raise the stakes.
High boost map selected and pull up to the line, she knocks out a 1.71 60ft going on to a 10.62 1/4 with a 137mph terminal, a new PB but still far shy of where it needs to be.
Now looking at dates for RWYB events at Shakespeare County for a proper shake down.
06 August 2014, 07:51 PM
#24
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Bloody awful on C85 as you need 35% more of it but actually quite good on pump fuel. Seen 30mpg on a run ☺
06 August 2014, 07:58 PM
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08 August 2014, 08:27 AM
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All of the breathers from the rocker covers and the block are connected to the catch tank which has a breathable cap.
09 August 2014, 01:36 PM
#28
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10 August 2014, 05:54 PM
#30
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None taken, lol.
It's hard to say without flow bench data I suppose but it certainly appeared to work in my case.
Don't forget of course that the stock manifold was designed with a completely different brief, they weren't concerned with revving to nearly 9000rpm or producing nearly 700bhp.
It's hard to say without flow bench data I suppose but it certainly appeared to work in my case.
Don't forget of course that the stock manifold was designed with a completely different brief, they weren't concerned with revving to nearly 9000rpm or producing nearly 700bhp.