jamse-r

It has nothing to do with the springs or retainers, they held up 10 dyno runs at 7,500 rpms with out breaking a sweat. These cams need some more tuning. I will take Nismo's advice and get a FPR and play with the timing.

__________________
96 G20 Turbo:Sold
93 NX2000: SOLD
91 SE-R: SOLD
99 G20T my DD
93 Mustang GT, built not just for straight lines....

hpro123

OK, quick comments.

Probably the "lean" area in the curves is REALLY affecting the engine & dyno. This looks like NO dyno I have ever seen from an SR20DE! Even S5 dynos that would supposedly be losing torque in the lower powerband are wayyy better than yours.

In all dyno diagrams I have seen posted in this forum, be it from stock, S3, S4, SD5 cams, the torque goes above the 100 ft*lb line from 2500 rpm (or sooner) and tops somewhere at 125-130-140 ft*lbs at the expected range between 4800 rpm (stock) and 5600-5800 rpm (S5s).

The torque curves in your dyno seem VERY steep, both in the low-mid rpm range (ascending) and on the high-rpm range (descending).

On the way up, this can be attributed t the lean condition (AFR > 13:1 all the way up to 4000+ rpm where the torque curve starts climbing) but on the HIGH rpm I find it difficult to explain...

Probably TUNING-TUNING-TUNING is in order but still... you should be making double the HP from 2500rpm up to 4000+ than you do now...

I have not seen any SR20DE diagram quite like this...

OnyxEros

Please do tune


*a note to people trying to read a dyno graph, all things being tuned properly when you see torque drop like that and HP hold you are floating valves.

__________________
VVL?
IX MR?
A race????

hpro123

* Good point but... if it is so inthis dyno, this would mean the valves are floating from ... 5800 rpm !!! There is no visible difference in the downward slope from ~ 5800 rpm and afterwards! I would be very hesitant to attribute this "deterioration" to valve float...

OnyxEros

that is why im saying the springs suck

if he can tune to the best of his ability and the decline is still like that...the springs suck

FastNX

That torque curve is incorrect.

If you use the formula

HP=TQ*RPM/5252

The early part of the curve makes no sense at all. How can the torque cross the HP curve at 4500 and 5252?

As far as tuning, a FPR will only help so much. It will bring the entire fuel curve up or down, but not flatten it out. You do need more fuel everywhere, but it definitely needs flattening out.

__________________
Climate Change skeptics are the new Flat Earth Society

OnyxEros

the torque curve is correct they are on different scales on either side of the dyno graph

FastNX

Thanks for pointing that out. Strange that they both don't start at 0.

It will be interesting to see what happens when this is tuned. It must be pretty soggy down low.

hpro123

Thanks for pointing this out Chris... Creatures of habit we are, so ... my mistake!!!

In view of the "scaling issue" in the dyno plot I must "ammend" the observations then!

jamse-r

Question, about the numbers down low, when shifting into 3rd I was taking second until 3-4000 rpms. should I have shifted sooner?

OnyxEros

are you saying you shifted in the middle of your dyno?

if so that would account for the torque drop before peak
Next time dyno in one gear only

HJBarker

a two-gear dyno pull!? Make that bad boy 3rd or 4th gear only!

4th gear is closer to 1:1 than anything else, iirc.

__________________
...another thread invasion from Harry, who came back and noticed that everything was suddenly fcuking different. What happened?
Not on the forum much lately since neck injury - we'll be back at it soon, babying the n00bies.

JWT S4, HS 6, Home Depot Intake, Hypercoil 2s w/ KYB "GR-Poo", CF Sunroof Delete panel, and other crap - where's my interior?

fmmrz5

so would these cams and s&rs work with turbo. or would the s4s be the only good option? sorry if this is a noob question but i know nothing of cams

supercowboy

by looking at the sheet my guess would be that he dynoed in fourth gear. Usually on roller dynos the load is more extreme and the SER tends to be real slugish in the low RPM. This is due to pushing The big heavy roller. Cam profiles can change a bit with boost applications. Sometimes you have to adjust cam timing to make better power. Turbo cars use oppisite adjustments in tunning then NA. DOHC cars make it easier to adjust for turbo setups because of the 2 cams. You can add or takeaway overlap to tune your timing.

__________________
06 monaro cv8
91 ser 311whp@15psi
92 nx 185 whp all motor sold!!
sr20ve in the House with some freeze
CT SUPERHERO

DO YOU KNOW WHO I AM!!! I THOUGHT SO!!!!

fmmrz5

isnt it best to get as close to no overlap on a turbo car as you can?

supercowboy

you need overlap in every car. You just shorten the time of the overlap on turbo cars.

fmmrz5

ok so do i want an intake and exhaust cam with the same duration? like these.

YounG Se-R

enought about the stage2 what about the stage 3 same price ..whos gonna take one for the team

2001SEdemBoobs

any updated dyno graphs?

hpro123

Boobs, what do you mean "updated" graphs?

There is no way you can update the old ones and he did not do a new dyno run or anything. Still, the ggraph shown is very much OK if you watch the scaling (as we did not really see it the first time around).

The dyno is fine. It's only "problem" is that the torque scale is on the RIGHT side and it starts from 100 ft*lbs. So, the torque curve you see there is really only the "top" part of the torque. Nothing wrong with it, except the fact that torque is below 100 ft*lbs from 3000 rpm to 3800-4000 rpm but this may very well be a tuning issue...