Xu10 On Xu9 - Going For 306 Intake!

[Saveit 0]

hi there,

 

I am looking to convert my standard 1.9 GTI by putting a XU10 head from a 306 XSI 8v on. A guy, called Jakob, here on 205gtidrivers informed me that Guy Croft had done a flowtest on the standard 1.9 GTI intake manifold, which showed a loss at about 10-15% because of "Wierd entry profile". This is because the intake air isnt entering the head "straightly" (horizontally) since the 1.9 gti manifold is arced. So i am going to put the 306 xsi 8v plastic intake manifold on, which is straight instead of arced. Moreover i can avoid porting the head by using this, and the throttlebody is also bigger on the 306 manifold. I have some questions though:

 

1. Do anyone have any flowtests or something suggesting that the 306 plastic intake manifold should be badly flowing? If not, then why havent anyone tried using the 306 plastic manifold? The way the air enters the head should be better by using the 306 intake manifold.

 

2. Should i use the injectors from the 306 manifold, or the one from the 1.9 gti manifold. Is there any difference?

 

Thank you

[carbers205 1]

From what I hear mate, the bonnet will not shut properly. Apparently the rad will also hit the bottom of the intake.

 

Andy

[Saveit 0]

Hmm okay. I will look in to that. But since it is a car used for racing, i can just make some changes to the bonnet and the radiator mounts.

[Baz 421]

Do a search!

 

You can modify the std xu9 inlet to match the head, the xu10 head has rounded ports and the xu9 is D shaped, so you have to match the 2 as much as possible, a good few people are running this setup on here, Anthony, 28Craig, Pugtorque iirc - with good results.

[Saveit 0]

I know that you can grind the ports so that they match - and believe me i have read every thread on this forum about this conversion. But if you had read my first post fully, you would have known that my reason for asking about this, is because i want to use the intake from a 306 since this should flow better with this conversion.

[Baz 421]

Fair enough, to my knowledge no one has done that, and i replied following on from the previous replies.

[Saveit 0]

Hehe no prob. But why hasnt enyone done that? Why bother porting the head to make the manifold fit, if the 306 manifold will pop right on?

 

Furthermore, is the injectors the same or what?

[welshpug 1,661]

probably because of the aforementioned issues with clearance and making it all fit, seems that the time is better spent on modifying the original 8v head/intake or going 16v.

[Saveit 0]

Yeah i see. But if the flow is better with the 306 intake, i think the time is better spend on making it fit instead.

 

Still looking for an answer to my injector question

[Jakob 1]

Hi Saveit

 

First of all it has been done before - actually Peugeot/Citroen (PSA) has always went that way OEM All XU10 heads are fitted with that entry angle. AND all thottlebody and carbs. conversion have that entry angle on the inlet manifolds ALSO on old XU9....should make people think when customize for more power...

 

And for non-OE applications - it has also been done before. BUT 95% of people go the simple route. The 205 GTI manifold is more easy to fit under a 205 bonnet. No one has ever questioned the 205 manifold before....but the flow bench figures dont lie !! What looks nice, and performe well under OE applications, dont always perform in the same way on custom "power" applications....205 GTI manifold being one of them IMO.

 

If you look at www.powerforum.dk at:

http://www.powerforum.dk/viewtopic.php?t=1...sc&start=10

You will find Dalen - 285hp on 1bar standard XU10 head and XSI manifold (actually it is from a 605 as it is in aluminium, but same shape and form - he welded the throttle body to the side to fit better). It is a 405. As I have previoulsy mentioned I beleive you will have to lower the rad in the front to have the XSI manifold fit under the bonet of a 205. The best thing is to collect one and measure it in the engine bay. Or have a custom made as I did.

(for those who wants to registor to view/comment etc. on the forum - the answer in the register-question is ÆØÅ, just copy these danish letters in the form and login)

 

If you are running your standard 205 engine management ALWAYS go with the standard injectors. Otherwise it will be pure kamikaze!

Running OE injectores on OE management will be ok as the LMM will return values to calculate the DC in the OE management and you will still be correct in the map (if mapped for that increased airflow, and it is OE mapped). However this will of course only work until you reach near 100% duty cycle. But it will work fine to the 155/160hp barrier (own experience with CTI 102hp injectors).

[Saveit 0]

Hi Saveit

 

First of all it has been done before - actually Peugeot/Citroen (PSA) has always went that way OEM All XU10 heads are fitted with that entry angle. AND all thottlebody and carbs. conversion have that entry angle on the inlet manifolds ALSO on old XU9....should make people think when customize for more power...

 

And for non-OE applications - it has also been done before. BUT 95% of people go the simple route. The 205 GTI manifold is more easy to fit under a 205 bonnet. No one has ever questioned the 205 manifold before....but the flow bench figures dont lie !! What looks nice, and performe well under OE applications, dont always perform in the same way on custom "power" applications....205 GTI manifold being one of them IMO.

 

If you look at www.powerforum.dk at:

http://www.powerforum.dk/viewtopic.php?t=1...sc&start=10

You will find Dalen - 285hp on 1bar standard XU10 head and XSI manifold (actually it is from a 605 as it is in aluminium, but same shape and form - he welded the throttle body to the side to fit better). It is a 405. As I have previoulsy mentioned I beleive you will have to lower the rad in the front to have the XSI manifold fit under the bonet of a 205. The best thing is to collect one and measure it in the engine bay. Or have a custom made as I did.

(for those who wants to registor to view/comment etc. on the forum - the answer in the register-question is ÆØÅ, just copy these danish letters in the form and login)

 

If you are running your standard 205 engine management ALWAYS go with the standard injectors. Otherwise it will be pure kamikaze!

Running OE injectores on OE management will be ok as the LMM will return values to calculate the DC in the OE management and you will still be correct in the map (if mapped for that increased airflow, and it is OE mapped). However this will of course only work until you reach near 100% duty cycle. But it will work fine to the 155/160hp barrier (own experience with CTI 102hp injectors).

 

Your knowledge is impressive. I will be using the 306 intake manifold, and the 205 gti injectors then. I am looking for around 150bhp with this setup (XU10 head, 304* Cam, 306 plastic intake, K&N filter, a bit more gasoline by adjusting the "clock" in the AFM, and a completely straight custom exhaust with the middlebox removen and only keeping the backbox). Remember it is used for racing, so nothing road legal is required.

 

I will have the car adjusted on a dyno, and i will post the results here! Surely there must be many wanting to know how much an XU10 will give on a standard 1.9 GTI bottom end.

Edited November 18, 2008 by Saveit

[Henrik P 0]

Your knowledge is impressive. I will be using the 306 intake manifold, and the 205 gti injectors then. I am looking for around 150bhp with this setup (XU10 head, 304* Cam, 306 plastic intake, K&N filter, a bit more gasoline by adjusting the "clock" in the AFM, and a completely straight custom exhaust with the middlebox removen and only keeping the backbox). Remember it is used for racing, so nothing road legal is required.

 

I will have the car adjusted on a dyno, and i will post the results here! Surely there must be many wanting to know how much an XU10 will give on a standard 1.9 GTI bottom end.

 

Hey. I am about to do the same tuning on my GTI, just with the std head and i am looking for a good cam. What cam are you using? You say it's a 304*?

[Jakob 1]

Just af few comments on that.

You have big 43mm inlet valves in 83mm bore (normaly 86mm for the XU head). That means a lot of valve shrouding due to the smaller bore and you will need high lift to compensate for that. I believe valve shrouding may be the reason behind all the topics "Help - I miss power on my XU10 swap" out there on different forums. So high lift cam would be much appriciated IMO - What are specification on the cam in terms of lift height?

 

The cam should possible send you up the revs for good top-end power. The inlet manifold also very much go in line with the cam. Short big runners returns high-end flow which go well together with aggressive cams like the one chosen. Long narrow runners peak with low-end flow (high velocify) and thereby low-end tourge which go well with mild cams/little TDC overlab.

 

The XSI manifold is in some terms a mix of that. It has fairly long runners but still not far from the end of a trottlebody's trompet, and the runners are quite big in diameter. Obviously the ultimate solution would be throttle bodies, but then you are looking at ~2000 EUR incl. an OMEX management which then is requiret (management).

 

If you have too much trouble getting the XSI manifold to fit, a possibility could be to find an alu-version (found on 605 and others), then cut the runners in half and have a alu-plenum weldet to it. That was pretty much my idea before I went the 100% custom way. It couldnt fit my engine bay due to servo/generator placement (generator is placed high if servo is included). Welding in founded alu can be difficult, but skilled alu-welders (like jbcoolers) can do the job. Though please remember, that I have NO EXPERIENCE in this matter regarding the xsi manifold flow on NA applications. This is only my thoughts, concerns and thinking.

 

Dont adjust your LMM before you know your AFR. If you plan going on dyno, then read from there and only then adjust if needed. It (duty cycle) should adjust it self as mentioned previously.

[Saveit 0]

Hey. I am about to do the same tuning on my GTI, just with the std head and i am looking for a good cam. What cam are you using? You say it's a 304*?

 

Yes a 304 degree cam. I will find some info on it and post it in here.

 

Just af few comments on that.

You have big 43mm inlet valves in 83mm bore (normaly 86mm for the XU head). That means a lot of valve shrouding due to the smaller bore and you will need high lift to compensate for that. I believe valve shrouding may be the reason behind all the topics "Help - I miss power on my XU10 swap" out there on different forums. So high lift cam would be much appriciated IMO - What are specification on the cam in terms of lift height?

 

The cam should possible send you up the revs for good top-end power. The inlet manifold also very much go in line with the cam. Short big runners returns high-end flow which go well together with aggressive cams like the one chosen. Long narrow runners peak with low-end flow (high velocify) and thereby low-end tourge which go well with mild cams/little TDC overlab.

 

The XSI manifold is in some terms a mix of that. It has fairly long runners but still not far from the end of a trottlebody's trompet, and the runners are quite big in diameter. Obviously the ultimate solution would be throttle bodies, but then you are looking at ~2000 EUR incl. an OMEX management which then is requiret (management).

 

If you have too much trouble getting the XSI manifold to fit, a possibility could be to find an alu-version (found on 605 and others), then cut the runners in half and have a alu-plenum weldet to it. That was pretty much my idea before I went the 100% custom way. It couldnt fit my engine bay due to servo/generator placement (generator is placed high if servo is included). Welding in founded alu can be difficult, but skilled alu-welders (like jbcoolers) can do the job. Though please remember, that I have NO EXPERIENCE in this matter regarding the xsi manifold flow on NA applications. This is only my thoughts, concerns and thinking.

 

Dont adjust your LMM before you know your AFR. If you plan going on dyno, then read from there and only then adjust if needed. It (duty cycle) should adjust it self as mentioned previously.

 

I hope the manifold will prove to be good. And i will make it fit if i have to Custom manifold is all to expensive for this kind of racing.

 

I will post some info on the 304* cam in here.

 

Yeah i will probably adjust the AFM on the dyno.

[mmt 15]

Hi.

 

Looks interresting your project.

 

What kind of racing are you going to participate in? Most clases have noise regulations so you might consider more than one silincer.

 

/Martin

[Saveit 0]

Hi.

 

Looks interresting your project.

 

What kind of racing are you going to participate in? Most clases have noise regulations so you might consider more than one silincer.

 

/Martin

 

Hi Martin,

 

Yes there are noise regulations, but the limit is 100db @ 3000rpm. We already have some racers where we only have the middlebox on, and there is no problem with noise. It is called Folkerace here in denmark. It is very similar to Rallycross (offroad racing on a track which is either dirt or part dirt/part tarmac) which is also known in Europe.

 

By removing the middlebox and having a totally straight exhaust with only the backbox, should give a lot more torque compared to a regular exhaust system. My setup should be very close (or maybe equal) to the performace of a bananamanifold-sportsystem (if that is the right word for it )

[Saveit 0]

Just got the info on the cam that i am going to use:

 

Product: PT27

Application; Supersports

Power Band; 2500-7000

Cam Lift(mm); I 12.49 E 12.24

Valve Lift(mm); I 12.24 E 11.93

Duration ; I 304 Deg E 296 Deg

Timing; 46/78 74/42

Full Lift; 106 deg.

VC (mm); I 0.25 E 0.30.

LTDC; I 4.31m.

 

Should be a fairly aggressive and good cam for this conversion.