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Author: Subject: AJ30 St220 inlet conversion and modification
benjamin_j_k

posted on 24/2/22 at 04:24 AM Reply With Quote
AJ30 St220 inlet conversion and modification

Hi all!!

first off i just want to say thankyou to you lot as you guys are the only place i seem to find any info on modifying this engine and increasing its output.

ive got a jaguar s-type with the aj30 and just want some more go out of it. so after stumbling across this page and people fitting the st220 manifold ive decided its a great idea haha. theres another tread somewhere on here that after a while goes into talking about needing a 15mm spacer made to fit the lower intake which seems to be the main complexity of it all. so after buying and recieving a 2.5 v6 cougar inlet, aaaaaand then realising im a huge idiot because the opening sizes are all smaller, ive managed to source an ACTUAL ST200 inlet on facebook marketplace.

for anyone reading this in the future or wondering the differences they are as follows:
cougar intake
throttle body opening: 57mm
short runner opening: 27mm
long runner opening: 30mm

ST200 intake:
throttle body opening: 65mm
short runner opening: 30mm
long runner opening: 31.5mm

With that out of the way, i arrive to my main question; how are people smoothing out the right side of the manifold where all those vacuum connections and pipes are? i think what im going to do is cut up the cougar manifold and see if theres an obvious answer but as to now im not fully sure i understand how people have done it.
image to show what i mean below:
[img]http://https://imgur.com/a/gbuHXEv[/img]

any input on this topic is appreciated thanks!

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40inches

posted on 24/2/22 at 09:10 AM Reply With Quote
Is this what you mean?
Description
Description

As far as extra power, I set mine up as per the S-Type and got 240bhp, a remap of the Megasquirt
produced 272bhp.

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sdh2903

posted on 24/2/22 at 09:38 AM Reply With Quote
I cut off all the unused bits and had them welded up. Mine ran at 225bhp at the hub on a hub dyno. Emerald ecu.

Inlet1
Inlet1


Inlet2
Inlet2

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CosKev3

posted on 24/2/22 at 10:49 AM Reply With Quote
quote:
Originally posted by benjamin_j_k
Hi all!!

first off i just want to say thankyou to you lot as you guys are the only place i seem to find any info on modifying this engine and increasing its output.

ive got a jaguar s-type with the aj30 and just want some more go out of it. so after stumbling across this page and people fitting the st220 manifold ive decided its a great idea haha. theres another tread somewhere on here that after a while goes into talking about needing a 15mm spacer made to fit the lower intake which seems to be the main complexity of it all. so after buying and recieving a 2.5 v6 cougar inlet, aaaaaand then realising im a huge idiot because the opening sizes are all smaller, ive managed to source an ACTUAL ST200 inlet on facebook marketplace.

for anyone reading this in the future or wondering the differences they are as follows:
cougar intake
throttle body opening: 57mm
short runner opening: 27mm
long runner opening: 30mm

ST200 intake:
throttle body opening: 65mm
short runner opening: 30mm
long runner opening: 31.5mm

With that out of the way, i arrive to my main question; how are people smoothing out the right side of the manifold where all those vacuum connections and pipes are? i think what im going to do is cut up the cougar manifold and see if theres an obvious answer but as to now im not fully sure i understand how people have done it.
image to show what i mean below:
[img]http://https://imgur.com/a/gbuHXEv[/img]

any input on this topic is appreciated thanks!


I really think you are wasting your time myself as the only reason we have used the ST200 upper inlet manifolds is due to the lack of bonnet clearance once the AJ30 is dropped into a kit car!

The standard AJ30 inlet or a ST220 inlet will flow loads better than the smaller ST200 manifold.

I think you are confusing the reason we get more power out of the AJ30, it's due to the aftermarket ECUs with custom mapping and VVT changes,tubular exhaust manifolds and no cats.

If a standard AJ30 inlet manifold would fit under the bonnet the ST200 conversion would never have been used!

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benjamin_j_k

posted on 4/3/22 at 03:46 PM Reply With Quote
hi thanks for the responses guys! made up as i was thinking i wouldnt get a response lol

i understand that you guys use these for clearance etc, for me, its more about ease of maintenance as the stock manifold is huge aaaand it looks really ugly, not only this but intake kicks off to towards the N/S/F and limits options for intake possibilities . in the long run my plan is standalone ecu, rods ,piper cams and verniers and turbo. i just want to build a show-ish car. i always loved how anywhere i pulled up in it, it'd get attention just because of it being an unusual sight on todays roads. id just like to be able to back it with power and a decent looking engine bay. im a mechanic by trade so im all about getting rid of the unessecary stuff: vvt(understand id possibly lose 5-10hp because of this but if i go turbo im not gonna miss it), stepper motors in intake, (and from what i can tell the aj30 doesnt have an EGR or charcoal canister, but if it did theyed be getting launched ) As for ecus it seems emerald is the favourite but if im honest i really like the idea of megasquirt if possible purely due to ive seen and heard of it more and ive got a friend who had a 300hp turbo vauxhall senator that ran it so even if i got stuck he could lend me a hand or some knowledge on the topic. with regard to the auto trans (zf6hp26) i plan to try run that on a seperate standalone and this is where i feel if integration was necessary, megasquirt would probably be easiest to acheive this on? i may be wrong let me know (only staying with the ZF as the torque capabilities over stock are far greater)
thanks!

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benjamin_j_k

posted on 4/3/22 at 04:00 PM Reply With Quote
quote:
Originally posted by CosKev3
quote:
Originally posted by benjamin_j_k
Hi all!!

first off i just want to say thankyou to you lot as you guys are the only place i seem to find any info on modifying this engine and increasing its output.

ive got a jaguar s-type with the aj30 and just want some more go out of it. so after stumbling across this page and people fitting the st220 manifold ive decided its a great idea haha. theres another tread somewhere on here that after a while goes into talking about needing a 15mm spacer made to fit the lower intake which seems to be the main complexity of it all. so after buying and recieving a 2.5 v6 cougar inlet, aaaaaand then realising im a huge idiot because the opening sizes are all smaller, ive managed to source an ACTUAL ST200 inlet on facebook marketplace.

for anyone reading this in the future or wondering the differences they are as follows:
cougar intake
throttle body opening: 57mm
short runner opening: 27mm
long runner opening: 30mm

ST200 intake:
throttle body opening: 65mm
short runner opening: 30mm
long runner opening: 31.5mm

With that out of the way, i arrive to my main question; how are people smoothing out the right side of the manifold where all those vacuum connections and pipes are? i think what im going to do is cut up the cougar manifold and see if theres an obvious answer but as to now im not fully sure i understand how people have done it.
image to show what i mean below:
[img]http://https://imgur.com/a/gbuHXEv[/img]

any input on this topic is appreciated thanks!


I really think you are wasting your time myself as the only reason we have used the ST200 upper inlet manifolds is due to the lack of bonnet clearance once the AJ30 is dropped into a kit car!

The standard AJ30 inlet or a ST220 inlet will flow loads better than the smaller ST200 manifold.

I think you are confusing the reason we get more power out of the AJ30, it's due to the aftermarket ECUs with custom mapping and VVT changes,tubular exhaust manifolds and no cats.

If a standard AJ30 inlet manifold would fit under the bonnet the ST200 conversion would never have been used!


40inches i think was saying even with it setup on the standard s-type file it made 240, which is the stock figure anyway... suggesting that surely even tho it may be slightly more compact, it doesnt rob power over the stock one. ill have to see anyway... sucks that hardly anyone plays with these as theyre belter engines, they really seemed to have got em sweet.

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CosKev3

posted on 4/3/22 at 04:25 PM Reply With Quote
quote:
Originally posted by benjamin_j_k
quote:
Originally posted by CosKev3
quote:
Originally posted by benjamin_j_k
Hi all!!

first off i just want to say thankyou to you lot as you guys are the only place i seem to find any info on modifying this engine and increasing its output.

ive got a jaguar s-type with the aj30 and just want some more go out of it. so after stumbling across this page and people fitting the st220 manifold ive decided its a great idea haha. theres another tread somewhere on here that after a while goes into talking about needing a 15mm spacer made to fit the lower intake which seems to be the main complexity of it all. so after buying and recieving a 2.5 v6 cougar inlet, aaaaaand then realising im a huge idiot because the opening sizes are all smaller, ive managed to source an ACTUAL ST200 inlet on facebook marketplace.

for anyone reading this in the future or wondering the differences they are as follows:
cougar intake
throttle body opening: 57mm
short runner opening: 27mm
long runner opening: 30mm

ST200 intake:
throttle body opening: 65mm
short runner opening: 30mm
long runner opening: 31.5mm

With that out of the way, i arrive to my main question; how are people smoothing out the right side of the manifold where all those vacuum connections and pipes are? i think what im going to do is cut up the cougar manifold and see if theres an obvious answer but as to now im not fully sure i understand how people have done it.
image to show what i mean below:
[img]http://https://imgur.com/a/gbuHXEv[/img]

any input on this topic is appreciated thanks!


I really think you are wasting your time myself as the only reason we have used the ST200 upper inlet manifolds is due to the lack of bonnet clearance once the AJ30 is dropped into a kit car!

The standard AJ30 inlet or a ST220 inlet will flow loads better than the smaller ST200 manifold.

I think you are confusing the reason we get more power out of the AJ30, it's due to the aftermarket ECUs with custom mapping and VVT changes,tubular exhaust manifolds and no cats.

If a standard AJ30 inlet manifold would fit under the bonnet the ST200 conversion would never have been used!


40inches i think was saying even with it setup on the standard s-type file it made 240, which is the stock figure anyway... suggesting that surely even tho it may be slightly more compact, it doesnt rob power over the stock one. ill have to see anyway... sucks that hardly anyone plays with these as theyre belter engines, they really seemed to have got em sweet.


Yeah but that was with no cats and tubular manifolds,a standard stype has tiny cast manifolds and two cats at that power.

If you unplug the stepper motors on your current inlet manifold does it put the car in limp mode?

Could be you will need to go to a aftermarket ECU straight away.

Also the standard TB is fly by wire,the ST200 is cable operated TB.

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benjamin_j_k

posted on 7/3/22 at 12:43 AM Reply With Quote
id be planning on going for a decat or maybe even sport cats. id like to do headers just not sure how to go about finding/getting some made up. as for the EML with steppers un plugged, when removing the old wiring i noticed someone had bodged it back together at some point so i assume there was some sort of wiring fault with it at some point, it did seem to me that one of them wasnt connected but i didnt have an EML and the car drove fine. ive also been looking into the piper cams like i say so surely that would eek out a fair few hp also. however i am now interested to see how the stock manifold would stack up against the st200 one with all the mods...hmmmm........ i think what ill do is keep moving on with trying to convert to st200 inlet and then put it all to one side once all parts are made up ready, refit stock setup, get all supporting mods done and try get a dyno run. if i get a load more than 270 then i think itd be fair to say that the st200 is more restrictive, again i understand that there is some variation between different dynos etc. so my next question would be what was the exact mod list that made the 270hp run?? was it just a standalone, st200 inlet, tubular headers and decat?
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CosKev3

posted on 7/3/22 at 09:41 AM Reply With Quote
The Piper cams are ridiculous money,if you go for fast road ones you can still run the standard valve springs and lifters,but you need to also buy the Piper vernier pulleys,total around 1500.
If you go for the higher profile cams you then need to use Piper valve springs and their shim under bucket lifters which will see you at a total of circa 3000.

I run newer injectors in mine out of a Mustang,but dont think they make it more powerful as such.

The way Jag have the VVT set up reduces power at high revs,they keep it on all the way to the limiter.
We found you can make more power switching the VVT off at 5800rpm then setting the rev limiter at 7100rpm.

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mgb281

posted on 29/3/22 at 06:48 PM Reply With Quote
Benjamin
Have a go at making your own headers, this is my first attempt (ever) at making headers for any engine. The photos show one of a pair for the AJ30 engine going into a MGB. I probably have about 300 invested in them including paying a professional welder to finish the welding (I just tacked them together), I bought the flanges from eBay and the bends from OORacing
I have not managed to add the photos

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