Modded engine with poor results

Neil1

Full member
Points
26
Location
Milnerton Cape Town
Car
Opel Astra 200ie 8v
Hi there,

Ok I'm rather very disappointed with this costly project I've done to my car, let me explain what I've done to my 2 litre 8v in order...

4-1 branches
57mm stainless steel free flow exhaust
Simota cone air filter (cold air induction)
Complete service
Gas flowed + port matched the head
272 estas billet cam + vernier pulley
UniQ chip + dyno tuned

Result.... A poor 91kw (123.7hp) at wheels :sad2: :embarrest: :confused:

The car drives pretty much exactly the same as it did before I even did these mods, if anything a bit smoother on acceleration but no noticeable power difference and idles a tad rough because of cam. The guy who did my head even said himself that something not right with that result. All he can recommend is getting my fuel supply checked out. He's well known around cape town (mike dixon) if anyone from cape town reads this.

What is also bothering me is that this car is rated 85kw (115.6hp) standard, before they put the chip on it showed 84kw on dyno with everything else done. Something is not rite here most definately...

Now I guess its a case of check this and check that, there was no report of anything looking odd or not right when the mechanic was stripping everything I was there when he did it. Anyhow I'm quite long faced at the moment, hoping someone will come along and make me smile with a helpful/experienced suggestion :sad2:
 
Manufacturers power numbers are usually at the flywheel that do not take into account transmission and frictional losses whereas dynos give you power at the wheels which will in most cases be lower than the manufacturers power numbers.
I and you should always get a dyno power run before and after any mods/tuning to see exactly what and where in the rev band improvements if any have been made.
Would suggest you find a reputable dyno tuner.Would change all fuel filters and check the in tank pick up filter as well along with having the injectors cleaned and flow tested.
I see you have a 4-1 header and they are a design that are more suited to a race car than a interference type ( 4-2-1) which are designed to work over a wider power band.
 
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Hi there,
4-1 branches
57mm stainless steel free flow exhaust
Simota cone air filter (cold air induction)
Complete service
Gas flowed + port matched the head
272 estas billet cam + vernier pulley
UniQ chip + dyno tuned

Result.... A poor 91kw (123.7hp) at wheels :sad2: :embarrest: :confused:

The car drives pretty much exactly the same as it did before I even did these mods, if anything a bit smoother on acceleration but no noticeable power difference and idles a tad rough because of cam. The guy who did my head even said himself that something not right with that result. All he can recommend is getting my fuel supply checked out. He's well known around cape town (mike dixon) if anyone from cape town reads this.

What is also bothering me is that this car is rated 85kw (115.6hp) standard, before they put the chip on it showed 84kw on dyno with everything else done. Something is not rite here most definately...

Now I guess its a case of check this and check that, there was no report of anything looking odd or not right when the mechanic was stripping everything I was there when he did it. Anyhow I'm quite long faced at the moment, hoping someone will come along and make me smile with a helpful/experienced suggestion :sad2:


115bhp at the flywheel (where manufaturers measure it) will be around 94bhp at the wheels so 123bhp after the mods isn't tha bad.

4:1 manifold will only really improve top end power - say 4bhp
Freeflow exhaust - Say 4bhp if lucky
Air filter, bugger all. OK, say 1-2bhp
Complete service - back to factory spec bhp.
Cam - No idea on spec, but with compatible head and valve mods - 15bhp
Remap on a N/A car (I assume there is no turbo) will improve power by around 8%

94+4+4+2+15*8% = 129bhp so I reckon that you are about in the right ballpark. I know nothing about the cam spec and headwork but you make no mention of bigger valves which would allow the head and cam to work far better. Head work without bigger valves and carb/injection mods won't make a heap of difference and can actually make matters worse as you are only doing half of the job.

If cam is making engine rough then there is a missmatch between cam/head/valves/fuel supply/timing. Too much cam lift for the rest of the engine spec is often the reason for this. High lift cam with a 4:1 exhaust will give a rough tickover. without additional mods.

If all he can suggest is looking at the fuel supply then no wonder he is well known - well known for not knowing what he is talking about if you ask me!

I take it that the engine wasn't built by one person but put togehter from a collection of parts?
 
--->Should be a bit faster due to a lighter wallet:sad2::<---

U rite on the "money" there :cheesy:

But even still me + a few others expected more, maybe something is amiss - and after driving it there is absolutely NO difference felt... Oh well like they say in SA - kak en betaal - #!#!#!#!#! and pay. Maybe this car modding is not for me, or I've approached the wrong persons for advise and followed it leading to my disappointment
 
This is the kind of reply I was expecting so a thank you is obliged ;)

The mods I performed was recommended by a number of "reputable" persons, giving less stress of existing engine components without having to replace certain parts.

Complete service included new spark plugs - petrol filter (by pump) - oil filter + oil - air filter which is cone air simota.

I bought the car with the 4-1 branches already installed, I then went and put a cowley 57mm free flow. The cam I had to get specially made for the OPEL/Vauxhall astra, which was part of the gas flow + manifold port matching of the head combination. No work was done on the valves they are still standard, the engine only idles rough due to cam but when driving its smooth no roughness. LOL basically the company that did the re-mapping + fitting of the uniQ chip is probably the best well known company in cape town - steves auto clinic. I noticed this evening when I took the cam cover off they (steves auto clinic) retarded the cam timing by +- 1.5 teeth (thats what it looks like) while doing the ecu remap. No injection mods + valve work was performed as you mentioned, maybe that could be whats missing from this entry level performance mod. I would hate to disagree with the persons opinion to check fuel supply as I would be insulting his intelligence that MANY people speak highly of.

The engine... I have no idea who worked on it before I bought it all I know is when I got it, it had those branches on and a 50mm standard exhaust, the rest I did. To put everything in a nutshell maybe I should just shut the hell up and live with it, you either go big or go home. I just expected more from what I've done and spent if I knew this was all I was going to get after spending all this money I would've just left it alone. Anyway...............
 
--->Should be a bit faster due to a lighter wallet:sad2::<---

U rite on the "money" there :cheesy:

But even still me + a few others expected more, maybe something is amiss - and after driving it there is absolutely NO difference felt... Oh well like they say in SA - kak en betaal - #!#!#!#!#! and pay. Maybe this car modding is not for me, or I've approached the wrong persons for advise and followed it leading to my disappointment
Mate hang in there and don't get in a blek ;) mood about IT'S all about checking everything and eliminating each possible item that may be the cause of your problems.Sometimes you get lucky and find it early in the process of elimination:bigsmile: and other times much later :sad2:
Don't know your exact cam specs but would suggest you contact the maker and ask about the idle lumpiness and find out if the AFM is clean and operating correctly with a pod attached as I have witnessed a toyota that had the factory AFM pipes replaced with nice shiny ally pipes with the AFM in place and a pod and it idled something terrible so they replaced it all back to stock and everything worked perfect so everybody was thoroughly:confused:
Is cam/cams correctly installed as per the timing marks as it is easy to be 1 tooth out.

I note you have a chip .I do not have any knowlege about them as I have a programmable Haltec EMS
 
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Yea sorry to hear the disappointment buddy, you'll have to find a better tuner to help you look it over back to front, did you do your homework on the chip? Always better to go for a stand alone system and use a respectable tuner, lot's more expensive but at least results are guaranteed.
 
What O.G says makes a lot of sense, increasing power on a naturally aspirated car has always been very very hard and costs a fortune, that's why most people stick to turbo's, a lot easier and cheaper. I don't know now but about 5 years ago the average was about R1000 a kilowatt to increase power on your car so be prepared to spend buckets of cash or leave it well alone. Good luck buddy.
 
I know nothing about SA tuning companies so cannot comment on their skills. However, there are a few so called 'well known' tuning outfits in the UK that shouldn't be allowed anywhere near an engine but people still go there because of their name.

Increasing a N/A engine's power requires getting more air into the cylinders, just like any internal combustion engine. However, without the help of a compresssor you have to rely on suction and rpm. This equates to bigger valves, longer opening times and higher revs. You appear to only have one of these so you can't expect a big improvement.

As I stated previously, the power you are getting is about right, without knowing what the claimed increase the cam and headwork was supposed to give you.
 
As ogs post plus I also wonder to what degree it is a tunable motor.

It is after all only 8v so wont exactly be well gas flowed . Im not sure you can really expect much better without any valve work.

The phrase "costly project" also means different things to different people . (as in whether you have calculated this in many hundereds or many thousands )
 
http://www.steves.co.za/Unichip_Why_Install.html#Uni-FAQs

These are they guys that put the chip in, "power gains of 10 - 30kw are common place" whereas I got only 7kw along with the other mods. So far all in all this has cost me R7650 justifying Hugoboss's equation of +- R1000 p/kw @ sleeper. I should give them a call on monday and question the retarding of the cam as the marks show its been retarded.

Basically this whole mod was aimed at better breathing and expelling of exhaust gasses - cone air filter draws in more air than standard filter - gas flow + exhaust porting for more free flow of air - 272 degree cam to keep valves open for longer - branches + exhaust to rid exhaust gasses more freely along with the chip which at the end didn't do much. Maybe in theory it makes sense do that but in practical it proved minor results. Thanx for all your replies guys, altogether you all saying the same thing - 8v not worth modding.
 
I would think that the claimed power gains would be more likely related to turboed cars

A performance cam can open the valves earlier and close them later so to get the full benefit it must be installed on the timing marks otherwise it cannot work properly.
AND if the head has been machined/resurfaced and you want the cam timing absolutely spot on then it needs an adjustable cam gear to allow the cam to be dialed/degreed in
 
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I suppose you are right TC, misinformed advertising luring people like me in to waste their money. I have a vernier pulley dont know what you guys call it there, its a modified cam gear allowing you to adjust the timing without having to take the belt off. Its retarded at the moment, by +- 1.5 teeth they did that when it was on the dyno and installing and tuning the chip.

I wouldn't want to play with the timing myself until I find out on monday what the reason was for doing that. The cam is classed as a 'sports cam', I feel nothing sporty at the moment hey its like nothing at all happened except a slightly more smooth acceleration. Same pull when putting foot flat same drop off on power at same revs. Who knows, maybe the person retarded it instead of advancing it...
 
If only you'd found us first and we could have guided you along in this project. An engine swap to the 16v turbo would be the cheapest way to make a lot more power.

I'd say the mapping needs to be adjusted to maximise all these mods. Did you have any angels cut around the ports to aid airflow into the engine? Check the cam lift is correct, I've known some fast road cams to be so ground down you lose a few mm of lift from them.
 
Yes Waynne that would probably be the best way to go, not fiddle and faf with small business. Nothing was done to the valves and no I never noticed any angles being cut around the ports. Just the head was gas flowed and ported.

Maybe the people I've been dealing with aren't skilled enough to have recommended doing the valve work while the head was off. I was told that after doing these mods I would hear a nice TANG down the exhaust but sounds exactly the same as it did before.

But its ok now I've had enough time to get over it, whats done is done
 
Guys I'm 90% sure I've found the problem, it lies in this head thats been "gas flowed and ported". I remember when I got the head back it just looked like someone cleaned it up and put some sandpaper in the ports and made it smooth, and after doing research it says its a time consuming process and needs to be flow tested on a bench and the exhaust ports are meant to have a mirror effect. It also says a "significant" power difference will be felt along the entire rev range, and as we all know thats not the case.

What I'm going to do in the next month or so is take this head to someone else and let them look at it and do the valve work as OG's reply I think I've made matters worse with this poor work done to the head. I'm sure thats the problem here, all the better breathing mods are there but the head can't provide for them... More labor + gaskets on the cards again for someones poor work
 
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