Guest joney Posted May 24, 2006 Evening gents I've got a P1 306 XSi that has the XU10 J2 engine that I see a few of you have used the head on your XU9 blocks (creating some wildly different opinions in the process!) and I'm trying to find cheap ways to improve the performance, so was thinking of getting an XU9 inlet manifold to replace the horendous lump of plastic it has as standard as all the conversions I've heard of retain the XU9 inlet. I'm led to believe that the XU10 head flows about 15% better than the XU9- but my car, in strong and healthy condition made 130bhp on a RR (110@wheels) with decent exhaust and de-cat, which is about the same as a good XU9 makes in equivalent trim.... which shows that there is room for improvement in my setup, simply using a hybrid of standard pug parts. Basically the advice I'm after is: 1) First and foremost do the XU9 inlet and XU10 head go together easily? 2) Will I need to port-match to get any gain over standard? 3) What sort of benefit and time are we talking about for port matching; 2-3bhp for a few hours of my time, or something more substancial? 4) Does the XU9 cam make a notable difference? If someone has info on the difference in duration that'd be great. 5)Is it worth considering the 205 ecu ie: are it's standard settings are more agressive? I realise it's not the normal questions you get as you're normally looking at things from the other side of the table, but if anyone has any info that will help me out I'd really appreciate it... Share this post Link to post Share on other sites
Guest joney Posted May 24, 2006 (edited) Has this already been covered by anyone in a thread that I've missed? I spent a large amount of this afternoon trawling through the threads on XU10 heads etc, but it's a section of the topic that hasn't really been given many column inches from what I've seen If it has been covered before a link to a thread would be great... Edited May 24, 2006 by joney Share this post Link to post Share on other sites
Dom9 2 Posted May 25, 2006 1). Yes, it bolts straight up to the head but requires port blending to get a smooth transition from the square manifold port to the round cylinder head port. 2). Yes, see above! 3). Order of single figure bhp, still worth spending a couple of hours, 'cos that's all it is, doing it. 4). I don't think anyone knows the actual duration of the XSi cam, but the XU9 GTi cam is meant to be a fair bit wilder, so wort installing since it is so cheap to find! 5). This is what I'm wondering with your setup.... ... You would be best sticking with the XSi management I reckon, however, this will mean that you will have to adapt the XU10 throttle to fit the XU9 manifold and make sure you have all the right connections and plumbing on the XU9 manifold as the ECU's were quite different in how they worked. I don't believe that the XU9 manifold, on it's own, will be that much of an improvement over the XU10 manifold, especially when you take into account the fact that it might be an arse to get it all to fit and plumbed in under the 306 bonnet. If I was on a really tight budget I might look at getting a 1.9 cam and maybe a vernier pulley and investing a few quid in going to a rolling road to get that cam set up. It would probably only cost you £200-£250 for the pulley, cam and RR time and you might see a few more bhp. If I had a bigger budget... I would whip the head off, get the 3 angle seats, which seem easier to cut on the bigger valves, a skim for extra compression, then add the GTi cam and vernier... Once this is all back together you are probably looking at nearer £500... If I had even more money and felt that the XSi ECU could handle it, I would do as above but invest in a CatCam 279° cam and look for a CR of around 11:1... Now, I'm assuming that you would stay on the XU10 manifold at this point. Other than it's shorter runner length, I don't see that the XU9 manifold would be much less restrictive and I think the runners are actually smaller in cross sectional area... It might be interesting for someone to do back to back tests with swapping the manifolds, but once you have port matched the XU9 manifold and XU10 head, you can never really go back to the XU10 manifold as it will be port-mismatched (is that a real thing?) and screw up the flow. I reckon the XSi managament would handle the XU9 cam, a light skim and 3 angle seats... But if you start looking at swapping cams for something even more aggressive, then you might want to look at stand alone management and throttle bodies... What's your budget? A few XU10J2 topics should have covered most of this stuff, but it won't be spun from the 306 POV, hence I don't think there will be much direct info for what you want to do, although most of it will be generic! Share this post Link to post Share on other sites
Guest joney Posted May 25, 2006 Cheers for the reply Dom, what you said about the 306 POV is exactly where I'm hitting my stumbling block From the sound of what you've said and other people's experiences as well the GTi cam/vernier is definitely worth getting, and a couple of hours on a RR to get everything tuned again should be top of the list- I'll look into this further, thanks Budget wise I'm looking at "as tight as possible" really, as I'm going to be fitting a gti-6 or Mi16 engine in the future with a view to getting around 200bhp, so anything done now is a stop-gap, drop my nurburgring lap time below 9 minutes (although dumping 100kg of ballast, aka my mate Steve, may be a good idea as well!), and generally keep me entertained; I'm an automotive engineering student, so anything that can increase my hands-on experience along with the academic skills I'm learning at uni is always going to be a big plus As for the manifold your thoughts seem to create another question, of why do people using the XU10 head use the XU9 inlet on their 205s? -Is it because the throttlebody and ECU are already in place that way; because of packaging(not a problem the other way BTW); does it give better performance; or is it simply just what the tried and tested method is and they don't want to mess around with it too much??! The reason I'm so interested in this is because I can pick up a 205 inlet for about £10, so with the TB and fuel rail swapped over I'm looking at just a weekend's work and very little money to get it all transfered....so if there is any performance gain to be had I'd prefer to do that than go out and piss my money away at the pub! :lol ...Oh, another thing is the plastic manifold dampens the induction roar, so a decent bark to go with my car's bite would be nice! Share this post Link to post Share on other sites
Dom9 2 Posted May 25, 2006 Well, it's an interesting question but most people who want to use the XU10 head in the GTI use the manifold from the orignal head because it's much simpler! All the plumbing, induction routes etc etc stay in the same place, so literally nothing needs changing except the head itself... I'm not sure you could fit the Xu10 manifold under the GTI bonnet, but I might be wrong! I haven't seen an XU10 manifold since I did my head about 2yrs ago, but doesn't it go over the top of the cam cover and have the air filter assembly sort of above the engine, on top of the exhaust? The thing that worries me is the clearance for the bonnet and the fact that the XU10 TB has loads of different connections for it's version of the SAD (IACV valve is it?) and it's own TPS and doesn't it have one of those heated elements in it? I'm sure you could ignore most of this but when the GTI guys swap the heads, they don't have to worry about the SAD, AFM etc etc 'cos they can just plumb it all straight back in, in the same location, which makes the job easier. Hence why I think you would be better staying with your own management! 1). It's better 'cos you don't have an AFM for the cam to disrupt, 2). It's already existing and you won't need to change any of the connections! Even if the GTI manifodl proved to be a performance upgrade, I would be shocked if it was anymore than a few bhp here and there and for the hassle of getting it all fitted, I can't believe it is worth it! If this is only a stop gap measure before installing a 16v engine, I would just whip the cam cover off and see what happens when you change the cam for the GTI cam and time it in correctly! As soon as you have the head off, costs start escalating and it's money that could have gone towards getting an Mi engine. Now, I'm not sure if it can be done without taking the engine out, but the other thought I had for my 16v XSi, was putting it up on a ramp and seeing if you could whip the gearbox off and get the crtank out, leaving the engine in situ. If you could then just swap the crank for a 1.9 item, you would get more capacity (2045cc) and a higher compression, with more squish, due to the extra stroke of the 1.9 crank. Thta way you wouldn't need to have the head off for a skim, which cuts costs considerably if you have access to a pit/ramp and some spanners! Obviously, that's over-simplified, but it's an idea and would allow you to gain the benefits of capacity, compression and squish all in one go... Whether it's possible or not, I don't know! The question then is whether the standard management can handle it without a remap and is the inlet restrictive? My best guess woul dbe yes to both although the mapping may be a fair way from optimum and the inlet will restrict it, however, I bet you'd get a fair torque hike, particularly at lower rpm. FWIW I've found a fully rebuilt Mi, although it's been standing a while, for £200... 16v bargains are out there, so, except for the GTI cam swap, if you already know you aren't going to stay 8v, I wouldn't bother! Share this post Link to post Share on other sites
Guest joney Posted May 25, 2006 (edited) thanks for the advice Dom, looks like I'll be getting a gti cam sorted then and I'll have a look at how easy a 205 manifold will go in terms of wiring routing and if the XU10 tb will mate up nicely, but only as a back up plan or to keep me out of the pubs at the weekend! I hadn't realised you could get rebuilt Mi's that cheap, so that may be getting done sooner than expected- I guess my current setup is putting out 140bhp (as it sticks with my friend's GTi-6 in a straight line and the corresponding bhp/ton needed for that gives that figure), so a 15-20 bhp increase for about £200-300 -plus a few grazed knuckles thrown in for good luck- sounds like a bargain. GTi-6 engines are still at the £400 mark so it'll almost certainly be the Mi route. If I can get down to an 8:50 at the nurburgring I'll be as fast as my mate in his Evo TME Cheers for your help Dom Edited May 25, 2006 by joney Share this post Link to post Share on other sites
Dom9 2 Posted May 25, 2006 To be fair, I'm very lucky to have found that engine and it won't come with the loom etc I'm guessing!? I will fill everyone in next week, once it is in my posession! It does come with an inlet manifold for TB's though... My original plan was to sell the head and stick an 8v head on with a few mods discussed with Matt at QEP, but I may just bang this whole engine in, if it's good, and buy TB's and a KMS from Matt... Anyway, back on topic, my point is that I reckon you need to budget at least £400 regardless of whether the engine is an Mi, GTi-6 or S16, to make sure you have the loom and the necessary bits... Then you still need to change the belts and maybe even rebuild the thing, so I guess if you have a few quid spare you may want to do the 8v as a stop-gap! See what you think about the GTi manifold, but I really don't think it will be worth the hassle as I'm sure I looked at trying to fit the larger XU10 TB to the XU9 manifold and it didn't look to be an easy task at all and you can port the XU9 TB anyway, if you feel it doesn't have enough area! There is also no reason to neglect the pub! Shame on you! I would be SERIOUSLY surprised if you could get anywhere near 15-20bhp with the 1.9 cam and no other work! When I built my XU10 head I had a large skim, 3 angle seats, CatCam 279°, vernier pulley, ported inlet manifold and fully ported head and I was hoping for 150-160bhp... I reckon you would see about 5bhp from the cam and pulley alone, maybe a bit more if it's timed in and setup correctly... But you would need the head work and extra compression to get anywhere near the 15-20bhp mark, maybe even a wilder cam... Hence why the crank swap could be interesting as it kills 3 birds with one stone! You could always talk to Autosprint in Brum as they do regrinds on the GTI cam for around £80, so that might save some cost, again though - you need to get that CR Up. The more I think about it, it sounds like you might have access to some skimming facilities... It may be worth pulling the head off? GTi cam = £10 Regrind = £80-ish Skim = £50-ish New HG, gaskets and bolts = £80-ish Setting up = £100 ?? So... £300? that's without any port or seat work... But you may be able to do the skim at college or get a mate to do it for nothing... Same with the seats! Budget £1k for an Mi16 swap? So, you could 'save' 30% towards that by not doing it? What's your time around the 'Ring? 9mins is shifting!! Share this post Link to post Share on other sites
Guest joney Posted May 25, 2006 (edited) The 15-20bhp I mentioned was in reference to an Mi16 conversion, rather than fitting the cam etc- I'd be happy with the 5bhp you suggest for that : I realise my biggest gains are going to come with good porting and then TBS and ECU; but until then it's stealing back the odd bhp here and there, learning my way around the engine a bit more, and getting better drivability if possible as the cash just isn't there About £1k sounds *reasonable* for an Mi16 conversion, but TBH I want to get my conversion done for less- with me having a 306 I can just get the front subframe from a crashed gti-6 and bung the mechanicals straight in- probably only looking at £500 for an insurance write off, and after that it's just time spent in the garage. If an Mi will work out cheaper I'll do that, but only If I can hit my 200bhp target for the same overall money- £1k gets cams and ecu done by a repuatable tuner on the 6 engine which hits 195bhp with only a mild cam profile, so something wilder will easily get over the magic figure (I've heard of 214bhp @fly for this, but prefer to estimate my own from an @wheels result and 13-17% losses instead of the 20-25% RR's often factor;)) and as it's a track car a bit of low down sacrifice is acceptable. Definitely the 1st thing for me to do is get the car RR'd as it is, as that will let me know where I stand so I can work out £/Bhp on various mods and take it all from there, as otherwise I'll just get mindboggled by all the possibilities..... I went to the Nurburgring over easter for my 1st trip and did a 9:09 with a rather hefty passenger (100kgs ish!) on Dunlop SP9000s which I was understandably chuffed with for a 10yr old french hatch - there weren't any more than 1-2 seconds delay from traffic as it was a really clear lap, so not really going to pull out more time there, but loosing the passenger should save me a fair few seconds (5-10? over 540 seconds?) as there were several sections where I really felt the car struggling for power, and semi slicks should make the most of my coilovers and probably see a 20-30 second improvement, judging from friend's experiences and the usual hearsay Do many guys make the trip to Germany from here?? It's becoming a big part of our social scene over at 306gti6.com with loads of trips scheduled throughout the season Edited May 25, 2006 by joney Share this post Link to post Share on other sites
Dom9 2 Posted May 25, 2006 A few people from here are regular visitors to the 'Ring, although I haven't been myself for years now! That time is really, really good especially with 100kg of passenger (although he's not that heavy )! I keep forgetting you have a 306, so yeah, I guess a crashed S16 or Gti-6 makes it a fair bit cheaper for you! It would be nice if you could have a go at some back to back testing on your 8v XSi engine as there are certainly some people on here who would be interested. If you get a base RR figure then just swap the cam over, that would be a very interesting result as the assumption has always been that this is an uprgrade. Keep us informed of how you go! Share this post Link to post Share on other sites
Guest joney Posted May 25, 2006 (edited) I'll try and come to an agreement with a RR company for multiple runs etc so I don't end up with a huge bill from them *as well* as for all the parts, and labour for the stuff I pussy out of doing myself....! What are the forum rules on giving free advertising to companies who do you a deal on this kind of thing? I saw we're not allowed to have adverts for 3rd parties in our sigs, but would I be able to use some exposure on a thread here as a bargaining tool? i.e praising their skills and generosity and posting phone numbers/websites and general brown nosing? (as opposed to military scale bombardment of plugs) It'd be nice to get some conclusive proof on which inlet system works best, what gains are possible, and how much it all costs; from what I've seen people often get a base reading, but then get all the work done, so it's hard to isolate the gains- or indeed if anything looses you power, as I guess with these slightly bodged (even though it's often all well thought out and carefully executed!) systems not everything is going to work as nicely as hoped. I'll keep my eyes open for people going to the 'ring, I guess in the meets and events section? I'm going over in August (10-14th) with a few gti-6s and I saw plenty of 205s last time, so I'll keep my eyes open for forum stickers etc Steve weights about 16 stone, so maybe that is a little bit below 100kgs? anyway, if I loose him, get my bro lashed in the seat instead (11 stone like myself ) and some semi slicks I'm sure I'll get burried down into the high/mid 8 mins... Edited May 25, 2006 by joney Share this post Link to post Share on other sites
pug_ham 244 3 Cars Posted May 26, 2006 From what I remember when I stripped the head from a 306 XSi I think you'll find it nigh on impossible to mate the TB from your car to the XU9 inlet as they are mounted in a completely different way but without comparing them both side by side to see if there are any issues I'm working purely from memory. Dom, you are right. The air filter sits on top of the head over the rocker cover on the XU10 engine in both the 306 XSi & late model ZX Volcane. AFAIK the 306 XSi uses Magnet 8P management so it is mappable (at a cost) for various specs, even up to fitting TB's. Not knowing the current compression ratio of the XU10 engine compared to a 1.9 8v but if they are very close you might not need a skim immediately to get an idea of what a difference it makes on your engine for relatively little expenditure. Graham. Share this post Link to post Share on other sites
Guest joney Posted May 26, 2006 From what I remember when I stripped the head from a 306 XSi I think you'll find it nigh on impossible to mate the TB from your car to the XU9 inlet as they are mounted in a completely different way but without comparing them both side by side to see if there are any issues I'm working purely from memory. Cheers for that Graham, I'll proceed with caution; it may be worth my while buying an inlet for £10-15 giving it a fair bit of thought with the parts in my hands, and then if it won't work simply sell it on for the same money Dom, you are right. The air filter sits on top of the head over the rocker cover on the XU10 engine in both the 306 XSi & late model ZX Volcane. AFAIK the 306 XSi uses Magnet 8P management so it is mappable (at a cost) for various specs, even up to fitting TB's. Yeah sorry I forgot to confirm that- the inlet tract design and filter location is absolutely useless over the top of the engine as it's always going to be getting heated air- *if* I can get the 205 inlet to fit I can put a NACA duct in the bonent and pipe cold air straight into the throttlebody through an enclosed filter system The ECU being mappable sounds very useful as bike TBs are definitely on my wish list thanks for your input Graham Share this post Link to post Share on other sites
Guest joney Posted July 5, 2006 Afternoon guys; I thought I'd resurect this thread now as I've been working on a CF bonnet and only now I'm finally getting around to doing this in preparation for going back to the nurburgring in August; Smighall has told me he has an inlet and cam available for me, but I've read that the 1.6 cam has more lift but less duration than the 1.9 item, so I'll be needing to source the 1.9 cam separately. I couldn't see any cams for sale (or at least recently) in the for sale section, and haven't had enough useful posts yet to be able to post a wanted advert, so I'm having to use this thread as an ask for help... ....If anyone has a 1.9 cam for sale (or knows someone who has one for sale) that is in good condition then I'll be interested in buying it from them; I think about a price of £10-15 is what I've seen previously, so if they can sort me out with one including delivery for around £20 then that would be marvelous Cheers guys Share this post Link to post Share on other sites
