Thread: VE Troubles!

I have recently done a conversion to a VE on an Almera GTi N15, I am having some issues and i hope i can get some help, Here is the Spec list:

SR20VE
SR16VE Cams (Although might be SR20VE cams, the guy i got the engine from said it has SR16VE cams but given by the dyno i am not sure).
SR20DE ECU Mapped by H-Dev
Greddy MSS Manage Cam Switching - 4500 Int + 5500 Exh
Timing 15 Degrees - Using modified DE Distributor
2.5" SS Autochrome Header (Matched for the VE)
333cc Injectors
Cone Filter
2.25" Scorpion Catback.
NGK Grade 7 Iridium Plugs


To have the car mapped the car had to drive 400 miles to get there. I only ever run the car on 99RON (UK) fuel. Fuel economy was great on the way there. was better than expected and engine never missed a beat. For the Remap on the Dyno, that was when i fitted the new NGK Iridum Plugs,

Here is the Dyno Sheets for the mapping after it was remapped.





As you can see, 180BHP ATF and 149.5 WHP.

One of the issues i am having is when you do a gradual Acceleration on the pedal, the engine jerks between 4k RPM and 6K RPM, If you plant the foot to the floor from low engine speed the speed comes up and no hesitation is felt. Hence the Hesistion never showed on the dyno.

We have now generated a new issue with the emissions test. The emission shows CO as 2.30 CO % Vol, UK limit is 0.20. its like its seriously over fuelling.

Whats confusing is that when i checked the plugs, they were sort of a nice clean brown colour. I have changed the MAF, Lambda sensor, Dizzy Cap, Rotor Arm, HT leads also,

The power is the least of the worries but would like to know why it under performed, but the emissions are the worry, Engine below 4k rpm runs really smooth, get good gas mileage, plugs and Lambda state shows fuel is burning cleanly. (sort of a rusty brown).

Any ideas??

Initial ideas:

*Unless the guy who sold you the engine is a real tricky bastard, check the painting on the middle of the cams (just open the valve cover to check): the intake should have a green paint mark and the exhaust a sort of brown mark (beige? is that a color?). Although the exhaust SR20VE cam is the same color, the intake is orange.

*Is the cam timing correct? No tooth skipped on the sprockets?

*Lose the Grade 7 plugs. Get grade 6 or even grade 5 plugs, this is a stock engine, not turbo or nitrous.

*The 2.25 exhaust does not help. Change to at least 2.5, but Id say 3 inch once and for all.

*Why the odd cam changeover? Did you dyno checked it gave the best power this way? Id say 4800 for both.

*Id frown over that tuned ECU.

*Check TPS around 0.48 - 0.5V

Did the "mapping" that was done include cruise area of the map? usually tuners focus on the WOT (full throttle) area which is why it would seem to drive fine when you floor it, but the cruise area of the map is very important for normal driveability.

just to add to the mix i just had my de/ve headswap mapped on the same dyno. it's a dyno dynamics btw, a heartbreaker i'm thinking.

here's my spec...

de block
cp 12.5:1 pistons
acl bearings all round
arp rod bolts
16ve head
n1 cams
ve oil pump
g-spec underdrive pulleys
hks mushroom filter
powerland 4-1 header
3" decat
3" mandrel catback
cosworth 1.5mm head gasket
h-dev tuned ecu


and here's my graph, 207bhp, 173whp, again pretty low imo considering spec. I think it's the dyno dynamics tbh, not too bothered as it feels savage!!

EDIT: note the sh*ttty plateau is due to my mss not working properly so both cams are switching together, i think i could do with the intake switching earlier




also, the guy who mapped the cars just e-mailed me about the whole dyno thing...

His s13 det made 483whp on janspeed dynojet over here, shortly after it made only 460 at the fly on this very dyno dynamics?! Massive difference but says it all about this particular dyno dynamics. I'll get a dynojet for comparison but tbh, fu*k figures it feels awesome on the butt dyno

stig don't worry about the power at all. just look into the emissions, cat i say

I will whip the cam cover off and have a lookwhen i get the time to do it.
We are gonna get a new 3" exhaust fitted next year,
I would have assumed the tuner would change the cam change points to get the best out of the car.

As far as the cruise map is concerned it explains a lot.

A lot of Honda guys running 2.25" exhaust on their up to 250HP K20 engines. I dont see this as a problem. 3" is over rated.

For this application, SR16VE cams, I would agree that a 3" might be overkill. On the dyno, with a similar setup, I compared a 2.5" and 3" VRS/Magnaflow systems and concluded that any difference in output did not justify the increased exhaust noise. Although I might have squeaked some more power out of the 3" system with tuning, I decided to run the 2.5" system.

However, I have also seen a 2.5" system compared to a 60mm HKS really wake up a DE with SR3s (big gains on the dyno in the mid-range and up top) with no other changes. So I'm an advocate of the 2.5" system for the VE with SR20VE or SR16VE (non-N1) cams.

^ precisely, these exhausts may make a few horses difference, not the 20-30 this engine is missing. Same as my results above, i've got all the right supporting mods i'd say, fuelling s good, and my timing map shows ignition timing towards 30degrees in the top end. There isn't 30hp more to be had from the engine. This dyno dynamics just reads low.

TheStigP11GT - My set up is similar to yours, SR20VE w/ SR16 cams, except I have a 2.5" exhaust, BC springs & retainers, and stock pulleys. I made 178WHP after 26 dyno runs, so on a cooler engine I'd be at the 180-182 WHP range, and the car feels & runs HEALTHY.

I think the cam changeover is causing the jerkiness between 4k-6k. I have mine switching over at 5k for both. Stock SR20VEs had switchover at 5200int/5600exh. I'd tune on the dyno where the best switchover points for you would be. Also, your exhaust should be at LEAST 2.5". You're choking that engine, especially up top. My SR16s rev out to 8k, with peak power coming in around 7600 or so. Yours is dipping after 7k.

I measured the exhaust on the car that the engine came from, that was also a 2.25" mandrel bent number, Which is the same size thats on the almera. I spoke to the Tuner today and told him my findings, We got a feeling becuse of the bad emissions that thecatalyc converter has collapsed. This might also be choking the power and will explain bad emissions. Like i said the Plugs look like the fuel is burning cleanly.

Also meant to add that it also has Outlaw Thermoblock Spacers fitted to it.