Giving the 3SGE another 2000rpm...

[jonb-]

While having a little think last night i came to the conclusion that a high revving normally asperated engine quite frankly... gives me wood.

I've little to no idea if this is even possible but I thought it would be an interesting one to ask and hopefully it'll spark many fantastic and interesting technical comments (or more likely at the moment plenty of handbags at dawn).

So, would it be possible to rebuild the NA to give it a much higher rev limit, maybe as high as 9-10,000rpm? I'm not interested silly turbo levels of power (some say they're too much for the chassis but that's for another topic) but breaking through 100bhp/litre and having rock solid reliability would be nice.

Thoughts?

Edit for first time readers: I ended up wimping out and buying a turbo

[Century Motorsport]

I had a mk1 engine that i rebuilt fully rebuilt and tuned. it had 290 deg cams and revved to 9,200rpm on itb's - it sounded amazing!!!

The key to getting high revs is the right cams and the right head work. The only down side is, the more aggressive the cam the more top end you get but the worse low down power yeu get. There are ways around it by raising the compression significantly to reatian some bottom end (it also helps it rev funnily enough!) but the bottom end will still be 'poor'.

For the rev limit your looking for i would say you need cams of 300deg and over which would inturn need itb's and at the minimum a greddy emanage or even better a full standalone (that way you dont have the hassle of getting your std rev limit moved)

HTH

Nathan

[Rogue]

So, would it be possible to rebuild the NA to give it a much higher rev limit, maybe as high as 9-10,000rpm? I'm not interested silly turbo levels of power (some say they're too much for the chassis but that's for another topic) but breaking through 100bhp/litre and having rock solid reliability would be nice.

The 3SGE engine can certainly be tuned to in excess of 100bhp/litre without resorting to forced induction, and I really would love for someone to step forward and ask us to build such an engine. We've even been discussing a theoretical build recently. The only problem I can see is that it would require the following:

- A big wad of cash.

...and it wouldn't yield as much power as the equivalent wad of cash would if spent on a turbo engine.



Rogue

[MR2Mania]

I agree with Patrick, the 3SGE is a good engine, and with the right mods, it could break 200fwhp. If I was doing this, I'd fit a set of throttle bodies with a standalone ECU, and a set of cams. I reckon you could that properly for about £2.5-3k.

It won't have much more torque though (not that you'll notice) - the gains are in revving higher (hence more power). So if you're expecting a big kick in the back, go for a turbo instead. But if you like a nice, responsive and revvy engine, it's worth doing this to an NA. However, see if you can find someone who's already had something similar done, to ensure that you could live with the "compromises".

[MR2Mania]

Oh, and nathanfreke seems like he's gone down that same route with the Mk1, so listen to what he has to say about how it changes the power delivery.

[Century Motorsport]

If i can get 204 fwhp (127.5 hp/litre) out of a 1.6 4A-GE then i'm SURE 220 out or a 3s-ge is obtainable.

The absolute KEY is headwork. Regardless of what anyone says - if you dont get that done right it just wont flow what is needed to make this power.

Nathan

[MR2Mania]

If i can get 204 fwhp (127.5 hp/litre) out of a 1.6 4A-GE then i'm SURE 220 out or a 3s-ge is obtainable.

The absolute KEY is headwork. Regardless of what anyone says - if you dont get that done right it just wont flow what is needed to make this power.

Nathan

Nathan, I agree with the possible power potential if it's all done right, although I hate quoting power figures in case people get disappointed. Heck, Owens managed to get over 220bhp and 9k RPM from a Corsa 1.6 engine - that car REALLY flies!!!

However, do you really think that there's that much power in the headwork? For example, do you think that headwork alone will come even close to the results you'd get from fitting an individual throttle body kit? I personally don't, but then I've seen how well various engines have responded to the throttle bodies alone. Personally, I'd do the whole lot (TBs, cams AND headwork), but I think the first 2 mods make the biggest difference, as the heads of both the Mk1 and Mk2 already breathe pretty well (and judging from the moderate flow improvements I achieved with the headwork done on my own engine, I think the cost-per-bhp of headwork is very high in comparison to the other 2, and hence why I see it at the icing on the cake rather than essential).

Out of intereste, did you do your conversion in stages, to get an idea on how much power roughly each mod was worth?

[Century Motorsport]

Hi, im not saying that if you get the head done properly it will yeild you masses of power - say if you put a fully ported head on a std engine you may get 5-7hp thats all. What i am saying though is that if you want to go high revving and big power - its not possible without a very good port job as a std or badly ported head will become the restriction in the setup. Also a good port job will increase the drivability and torque with aggressive cams.

I kinda did my engine in stages - first was the re build, balance, ecu, valve springs, cam pulleys, compression raise and head job. I ran it in like that and TBH it didnt feel much quicker than stock - then came the cams, on the std plenum it was SOOO peaky to drive and tickover was non exsistant!! So very shortly after came the itbs which smoothened the power right out and make tickover/idle 100%better. Lastly was many trips to the dyno - result ending up to be 204 @ 7996rpm whilst retaining the std exhaust manifold and downpipe as i had run out of cash!!!

The down pipe proved to be a big restriction on my last run - the higher up the rpm we got tuning it the shorter the runs as it was glowing red after seconds!! I guess a decent exhaust would have freed up quite a few ponies on top end power but ill never know as its sold now!!!

For good N/A performance you need all the ingredients for it to work!

Nathan

[Fred]

As others have said already , getting 100BHP/litre out of this engine should be a walk in the park (almost ) , they were getting those figures out of the Pinto(2litre 4 cylinder 8 valve) 20 years ago .

10,000rpm and 'rock solid reliability' would be nice , but an impossible dream I fear .

[Bender Unit]

I had a mk1 engine that i rebuilt fully rebuilt and tuned. it had 290 deg cams and revved to 9,200rpm on itb's - it sounded amazing!!!

Hi Nathan, what was the full engine spec? My AE86 will be landed soon and I will be building a 4AGE with the intention of making 200 FWbhp. Just interested to know what you did, what you kept and what you binned?

I have mentally planned whats needed (some of which will already be on the car) just interested to know what worked for you?

Cheers

James

[pnjmcc]

Hi All,

This is kinda along the lines I want to go but I will propbably NEVER have £2.5 to 3k to throw at the car, so I was planning cams, a unichip and some head work which I figured 1 - 1.5k is that way to low then?

Would you really need to get a stand-a-lone ecu to control this or would a piggy back do the job?

and how did you come up with that figure? (not disputing it just curious)

Cams 500
adjustable gears 200 a pair
ECU = 700
TB's = £ sorry no idea
Mapping and set up = 600
Head work = Again no idea

I am guessing that you would need to uprate things like springs and that as well, but what about the rest of the engine ?

Would the internals need to be lighted and balanced to rev further ?

Sorry for a lot of Q's

Regards
PaulM
92 G-Ltd.

[Bender Unit]

Paul have a read of this ...

http://www.billzilla.org/4agmods.htm#190hp

Whilst its based on the 4AGE it highlights the basics for NA tuning and you should be able to pull a few ideas from it for the 3SGE.

If you can do this work yourself then the only expense is the parts.

[MR2Mania]

Lastly was many trips to the dyno - result ending up to be 204 @ 7996rpm whilst retaining the std exhaust manifold and downpipe as i had run out of cash!!!

Ah, yes, forgot all about the manifold!! I bet there are gains to be made there, although I'm thinking more about the driveability. ISTR that 4-into-2-into-1 was the setup that seemed to be give the best midrange driveability on NAs, but it's been a long time.

Paul, the reason I mentioned a standalone was assuming that you'd also go for the individual throttle bodies, in which case the standalone is a MUST as the engine ideally needs to be mapped against throttle position to give you that responsiveness.

With regards to the rest of the stuff, have a look around at what people have been doing with this engine, as it's still commonly used for trackday cars. I'm too out of touch with NAs to help here mate, unfortunately.

[Bender Unit]

Ah, yes, forgot all about the manifold!! I bet there are gains to be made there, although I'm thinking more about the driveability. ISTR that 4-into-2-into-1 was the setup that seemed to be give the best midrange driveability on NAs, but it's been a long time.

4-2-1 for mid range 4-1 for top end power. The stock manifold and exhaust on the 4AGE is a restricition nearing 200 fwhp

Paul, the reason I mentioned a standalone was assuming that you'd also go for the individual throttle bodies, in which case the standalone is a MUST as the engine ideally needs to be mapped against throttle position to give you that responsiveness.

Its seems now alot of ITB set ups come with a full EMS system and there are quite a few on the market now and very comprehensive. Considering my options for the AE86 - Dual carb should be fun but ITB's will give me more power and reliability.

Cheers

James

[pnjmcc]

Thanks guys

Looks I have some learning to do then.

Regards
PaulM
92 G-Ltd.

[skinthespin]

Interesting, and well done to nathan for achieving these result, i think the fact not alot of this is done is because a standard turbo will run all day and have more power for a lot less hassle and cost so people don't bother.

I think lightening the internals is really important for reliability but should be done with good quality components, anyone weighed a forged piston comapred to a standard item, or maybe a rod?

Also you could lower the final drive ratio (thinking outside the engine) so the same speed is achieved in each gear to the standard car but at a higher engine speed, thus the force at the rear wheels is increased.

Would a 4A-GE be easier to make rev because of the lighter internals, I think it would be but by how much I dont know!

[dai21t]

I'll weigh pistons and rods later if I get a chance. I've got eagle rods and Arias pistons waiting here to be fitted once I get my block machined.

[MR2Mania]

Its seems now alot of ITB set ups come with a full EMS system and there are quite a few on the market now and very comprehensive. Considering my options for the AE86 - Dual carb should be fun but ITB's will give me more power and reliability.

Not to mention the problems you'd have in finding someone who could jet and "fine-tune" the carbs!

Way back when I heavily modded my Mk2 RS2000, I had to go to 6 dyno places before someone finally got it remotely right, and that was about 18 years ago!!

You'd be pushed to find someone who can sort out your carbs in this day and age, but at least ECUs allow you to optimise the fueling at every load point, unlike carbs which are a big compromise.

You never know, James, it *may* be the trigger you need to get you learning to map!!!

[Bender Unit]

Not to mention the problems you'd have in finding someone who could jet and "fine-tune" the carbs!

Well thankfully in the Village where my old man lives is a small group of vintage petrol heads who Dad is pals with. One used to build, race and tune Honda motorbikes in the 70's and 80's and the other guy is 80+ but can tune a set of dual carbs by ear. So they will be press ganged into giving me lessons on Carb set up.

You'd be pushed to find someone who can sort out your carbs in this day and age, but at least ECUs allow you to optimise the fueling at every load point, unlike carbs which are a big compromise. You never know, James, it *may* be the trigger you need to get you learning to map!!!

ITB's are a definate for me and I basically came to the conclusion that I would learn mapping in order to map them myself. I would have started this earlier but lack of work means I cant really spunk a wad of cash on the stuff I need. I would have liked to have mapped the Mr2 had I had the chance.

cheers

James

[Century Motorsport]

Well - in my build i soon realised that £1500 for itb's was out of my reach so as im mechanically minded and lucky enough to have the facilities i firstly made my own inlet manifold but the itb's i used on that manifold were way to big so i ended up ditching that and brought a twin 40/45 dcoe carb inlet manifold, i had 2 40dcoe webbers that were shot as carbs but the bodies and throttle linkage was good so i gutted all the venturies out, all the jets, everything bar the throttle linkage and butterflies. I then got the old choke restrictions and venturies and got them counter boered out to exactly 39mm - once this was done i re fitted them to the mouths of the carbs which gave me a nice smooth inlet track - that was my throttle bodies made!! The next obstical was getting a tps to go on the carbs...... after a quick google search i found a company called webcon who made tps systems especially designed for dcoe carbs!!! RESULT! So instead of spending £1500 i realistically ended up spending £200 for some itb's that do exactly the same job. Alright they dont look quite as nice but it enables you to have throttle body performance/consitansy whilst keeping costs down.

As for mapping - stand alone it the best. Looking back i wish i had gone that route but instead i went with the greddy emanage which i think is the best alternative to a full stand alone. I never had any real trouble with it at all but little niggly things like sending the std ECU to malaysia to get the rev limit moved to 9,200rpm was a pain in the ass and also i would have loved to be able to map the car on TPS only - not TPS and MAP as this would have made the idle perfectly smooth and driveability would be much improved!!

BENDER UNIT - if you wanna pm me i can give you some info on what i used and what i didnt - also some probs i found along the way. If you are thinking of keeping stock ecu and just using piggy back then i know a man in holland who can remove your rev limit and disable the map function so it only runs on tps!! (he can only do it on blue top ecu's where as mine was a red top and he couldnt get the eprom for it )

HTH

Nathan