Engine Issue - Coilpack? And manifold/exhaust questions

[Alexo]

Hi all

Ok, so after owning my new S15 for about a month now, and replacing the turbo gasket (Turned into a nightmare, Japspeed manifold not fitting, Japspeed elbow being poor quality too!) ive finally managed to enjoy driving it, up until last week..

Now, ive been searching the forum most of the afternoon to see if anyone has experienced the problems ive been getting regarding misifiring, running VERY rich etc.. and it seems to be a pretty common problem regarding coilpacks?

Basically im getting the usual engine being very lumpy on idle and when accelerating, to the point you can physically see the engine move in the engine bay, then also it sounding like a boxer engine!! Its only happened 3 times so far, but will only happen more often id imagine.
I reckon the best thing to do is perhaps buy one new coilpack from Nissan, and replace it on each cylinder to determine which cylinder is at fault?

So, although i have read up on the problem, and it seems pretty certain to be a coilpack, just wanted a bit of confirmation from people who have defonatly experienced the same, and the outcome they got.

Now, also, wanted a bit of advise with exhausts. My S15 currently has a Japspeed centre and rear sections, along with a fujitsubo downpipe. Now, i have just at the weekend fitted a Japspeed elbow which, i can only assume down to poor quality and manufacturing, has moved the whole exhaust over, to the point its touching the body of the car!
So, just wondered, again from experience, what people are running regarding exhausts? Im looking to have another go with a decent manifold that actually fits, then perhaps change the elbow and full system for something of far better quality.

Sorry for the long winded post, hopefully i can get a few opinions! :thumbs:

 

[craig8585]

Your engine symptoms are totally classic for a coilpack failure..

 

[Alexo]

Exactly what im thinking Craig! Just wanted a bit of reassurance more than anything

 

[craig8585]

It's most likely to be the coilpack nearest to the bulkhead too if that one hasn't been changed before

I can't help with the exhaust question though, but I do agree with the poor quality comment.

 

[Alexo]

Ill get one ordered up tomorrow and give it a try :thumbs:

Yeah, if im honest, i wasnt too suprised with the quality. I mean, im a true believer of "you get what you pay for" so obviously going cheap was never a good idea. I mean, in the past ive been a huge Honda fan, so have strictly stuck to running just Spoon and Mugen parts. Ok, expensive, but everything fitted perfectly and i never had an issue.

Im thinking with the S15, to perhaps look into a Tomei Expreme manifold, matched with the Tomei Elbow. It looks to me you cant get alot better than that? Then maybe go HKS for the rest of the system.

 

[craig8585]

I've currently got a Japspeed mani and elbow but recently had to get the elbow repaired because it had cracked (link) after just 12 months.. Tomei parts are very good, just very expensive. I had the rest of my system custom made so it fits perfectly but HKS and similar Japanese brands are all very good

 

[Fasthands]

I will be fitting Tomei Expreme header and elbow next week, I have Apexi 3" down pipe D-cat and HKS Hi Power the rest of the way. I will let you know how it turns out. regards the coil packs, I fitted Splitfire ones they are not the cheapest but made a massive difference, instant torque increase really noticeable..well worth the money imo. I will be getting the Vipec V44 ECU fitted too now it has finally arrived after been held up in customs. I got my header and elbow from Jappanese performance parts, they were superb service and willing to haggle, I paid £260 for the pair. They have just broke 3 S15's so they may have some tasty parts..

 

[LuPix_S15]

The Japspeed stuff I had was never an issue but then again I got the elbow and dowpipe at the same time - bolted with decat and then catback HKS Silent Hi-Power.

The funniest thing is the bracket item welded on the downpipe as it's supposed to be able to bolt onto the gearbox/mount area... are you having a laff?? Was about a mile off!!!

 

[Alexo]

So, just to update, ordered the coilpack today which, with any luck, will cure it!

This has been my first time using Japspeed, and to say ive been disappointed is an understatment. Perhaps ive just been used to the amazing quality of Spoon amd Mugen in the past, but both the manifold and elbow were so poor. To the point i had to send the Manifold back for a refund, as i simply couldnt physically fit the thing!! The elbow was a massive struggle, but it went on eventually.

So, exhaust, i think ive settled on going with Tomei manifold and elbow, cat-back HKS system then probably HKS downpipe too. Hopefully a setup that will work nicely together.

Having the S15 detailed on Sunday so i'll be sure to get some pictures up soon!

 

[eiden88]

Hi mate, are you italian?

 

[DeanS15]

one thing i will always say to anyone is buy a quality exhaust system - my hks silent hi-power is spanking after over two years, cleans up perfect and doesnt pit and rust like the poorer quality stainless - BUT - if i ever started again i would always have a custom downpipe made. just by doing this you can gain ground clearance (often the middle box or downpipe flexi are the lowest points), make sure the bracket is in the right place and get an exceptionally good fit - a flexi is not essential - as i have found - if the downpipe and manifold are braced properly. more often than not the exhaust isn't braced properly to the engine or box, this is the reason for stress cracking as they aren't moving together. other things like uprated engine and gearbpx mounts help a great deal as they limit the movement of the engine. less movement = less chance of cracking elbows and decats aren't as important to get big brands as they are much of a muchness, but poorer quality ones will pit and rust as after all, they are very cheap in comparison to jdm. don't forget to only use original nissan gaskets on the manifold and turbo - others will fail quicker and it's a pain of a job you don't want to do again.

if you don't want to spend as much money on a manifold, horsham developments do a pretty good quality item based on the expreme and it's fairly well proven now to work well and last well...i've run one for two years also.

 

[haz's S15R]

If you're on a budget the Megan racing manifolds and elbows are good quality and stand up to a lot. BTW expensive doesn't always mean good quality - a freind of mine has a GReddy manifold which cost a fortune, is paper thin and he has to weld at least once every 3 months!!!