LS3 top end swap

[mikeyb1987]

ringram said:

It's already idling pretty high.
850? 800?

7-800 I think. I'll double check it this weekend.

[mikeyb1987]

KMud said:

Isn't 800 normal for a manual? Low even for a cammed car? Or is that just what the gauge reports?

Yep, it is a bit low- I think I'll get it increased.

This is a better video of the idle during a cold start:
http://youtu.be/SZnYz_f3-Zs

[mikeyb1987]

mv6 said:

Sounding good Mikey.Have you gone for "rounder" tailpipes,or is it just the angle the camera is at?

Same tailpipes Roger- must be the camera angle.

[mikeyb1987]

jonnM said:

Sounds great

So what does 25% extra power feel like

Fantastic! The power builds to the redline- it's an absolute joy letting it rev out Acceleration-wise, the car feels like it's lost half a tonne in weight- gaining speed is effortless.

[mikeyb1987]

jonnM said:

Result! And the most important question....has it improved the lift-off pop & crackle?

It still pops and bangs like a good'un! In fact, there's (what sounds like) an occasional large explosion coming from the tailpipes when doing a full-bore shift.

You wouldn't have as many questions if you fitted a cam to yours.....

[mikeyb1987]

Gelf VXR said:

mikeyb1987, did you get a MOT done yet? What were your emissions like?

Hi Andrew. I haven't had a chance to get to an MOT centre. There's a few issues with the map, which I'm hoping to resolve next week. Once these have been rectified, I'll get the emissions checked.

[mikeyb1987]

bimbleuk said:

Good luck with getting it spot on in a couple of visits!

The driveability side ideally needs time, logs and varied conditions to get a good idea of what your combo likes. You've radically changed the characteristics of your engines airflow and then chuck in a cam with overlap which messes with the sensor readings around and just off idle.

All fixable within reason of course. For example your pops and bangs will most likely be a combo of the injector timing, fuel dynamics and DFCO tables needing some tweaks.

If I can have a perfectly driveable car without the MAP (installed for reference only), MAF, IAC sensors then rest assured you'll get there.

By the way I'm still working on my fuel dynamics but I have some major changes to the whole inlet geometry to contend with.

Edited by bimbleuk on Thursday 15th May 12:55

Some good valid points I'm past a couple of visits now, but I'm dropping the car off so he can have it for almost a week, so hopefully most issues will be 'mostly' ironed out.

I now know it's a long process to perfect and hone the map- had I have known that from the outset, I would've looked at getting my own copy of the software etc to log and tweak.

[mikeyb1987]

Gelf VXR said:

I just got my cam data from FTI for a custom cam after submitting their cam spec form, my criteria was for a daily driver, UK emmisions compliant, no loss of bottom end, maximum torque under the curve, and to pull to 6400rpm. Purchase is required before you can receive the spec.

Taking into consideration I would be swapping in LS3 hollow valves, increase compression slightly from .051 stock head gasket to .040 cometic gaskets,retaining 1.85:1 rockers. I also have a modified RC LS3 intake with runner bars + ¬8CFM

I wasn't too surprised to see the spec hardly changed from the SLP cam I already have installed

Installed SLP cam 216/229 113+3 .330/.331

Custom FTI cam 219/229 113+4 .340/.342 (.629/.633)


I was thinking maybe upto 223/231, but looking online 219/223 (LS3 valves) or 219/227 (L92 valves)is popular small cam now

http://www.g8board.com/forums/showthread.php?t=837...

http://www.gmhightechperformance.com/tech/lsx_engi...



Unfortunately im still out of the country working, itll be some time before i can get in installed

The 223/231 cam is the one I have.

If you need some new L92 valves with retainers, look on ebay

[mikeyb1987]

Gelf VXR said:

mikeyb1987 said:

The 223/231 cam is the one I have.

If you need some new L92 valves with retainers, look on ebay

I've ordered LS3 valves

Did you get your emissions checked yet?

Nice- LS3 valves are what I run.

Nope, still need to get the emissions checked- hopefully I'll get them checked in the next month or so.

[mikeyb1987]

Update! With sports cats the car is MOT compliant



It's close on the fast idle, but a pass is a pass. The tune is less than perfect, so I imagine the fast idle can be improved.

Just thought I'd update/confirm the cam is emissions compliant, in case others are thinking about cam specs.

Mike

[mikeyb1987]

A post in another thread made me realise I hadn't updated this thread for my results at Thunder road this year:

Best in class with a top speed of 169.20mph in a standing mile

Just need to find a way to squeeze an additional 0.8mph out of the car!!

[mikeyb1987]

SturdyHSV said:

Some ideas (not all of them brilliant ):

• Non-nostril bonnet
• Remove the rear spoiler
• Remove the wipers?
• Tape up some panel gaps

As you can tell, I'm of the mind a little bit of an aero improvement might be all you need. That or favourable weather (cold, no headwind)

Unfortunately as Paul has said, I ran without my rear spoiler (worth a couple of mph by the way ). Other ideas are good and along the lines of what I was thinking. Hell, plenty of tape and a tail wind I might even see 175mph

[mikeyb1987]

jameshsv said:

You have done a grand job mikey

Cheers mate, appreciate it

Looking forward to seeing yours up and running next year, particularly as I'm interested in centri chargers too In fact, I'm looking forward to seeing Stick's 454 running properly too!

[mikeyb1987]

Mud_ said:

mikeyb1987 said:

Cheers mate, appreciate it

Looking forward to seeing yours up and running next year, particularly as I'm interested in centri chargers too In fact, I'm looking forward to seeing Stick's 454 running properly too!

Does he still have it?

Hmmm, now you mention it, I have just remembered it was for sale, wasn't it?! Maybe he's going to treat himself to some classic muscle. If my memory serves, I think he has a thing for Chevy Nova's