LS3 top end swap

[mikeyb1987]

Yep, Ringram is correct- John Sleath is mapping it.
He has the car for a week, so hopefully any mapping issues will be sorted.

[mikeyb1987]

Another quick update.....

404rwhp and 450lb/ft of torque (at the fly, from 4,400 to 5,350rpm) Will upload graphs shortly. To say I'm over the moon is an understatement!

Just to clarify, that is 80ish rwhp from cam, heads and a tune

It made peak power at the limit (6,600), and with the cam specs, I know there is more on the table. What can the rods/bottom end take? The car has done 94k miles, so I'm tempted to err on the side of caution and leave it as it is. It is tempting, though, to up the limit and see what it will do up to 7k rpm...

[mikeyb1987]

[mikeyb1987]

jonnM said:

Great result Is that a 25% increase in power? You're going to notice that

Hopefully

[mikeyb1987]

KMud said:

Interesting stuff and a nice result - I keep looking at FAST intakes, but I think I'd rather go down this route one day. How are you finding the car behaves around town?

I haven't got the car back- need to go down and pick it up. Hopefully it will be ok around town. How's yours around town?

[mikeyb1987]

KMud said:

Didn't realise this was an LS2 only deal

Mine's getting there, but my cam isn't as big as yours

I know you uprated the injectors, but are you on the stock fuel pump?

Yep- unfortunately LS3 heads won't fit on an LS1

Stock fuel pump. I'll have to have a good debrief with John Sleath, but I'm presuming the pump is ok.

[mikeyb1987]

ringram said:

Nice job. AFR looks nice too. Let us know how it drives off idle.

No loss of torque across the dyno pull either from the larger cam.

Cheers Richard. I'll feedback re drive ability once I pick it up.

I owe you a pint as well, the next time you're in the Lake District. If it wasn't for your guidance on cam specs, I would still be scouring LS1tech/LS1gto!!

[mikeyb1987]

KMud said:

There are ballpark numbers on ls1tech (e.g., 425-475 whp here), but translate them into real money and yours starts to look close!

You're right- I must be close! Mine is making good power up to the rev limit, so hopefully that means the fuelling isn't an issue.

[mikeyb1987]

What will the standard bottom end take? It seems like they spin them to 7k in the US, with just rod bolts. Like you said, it's making peak power at cut off, so I will seriously consider looking into how far I can take it. I could even chuck on a FAST intake for good measure
It's a 114 + 0.

[mikeyb1987]

jameshsv said:

mine spin

mikeyb1987 said:

What will the standard bottom end take? It seems like they spin them to 7k in the US, with just rod bolts. Like you said, it's making peak power at cut off, so I will seriously consider looking into how far I can take it. I could even chuck on a FAST intake for good measure
It's a 114 + 0.

Mine revs too6900

How many miles has your car got on it James?

[mikeyb1987]

ringram said:

mikeyb1987 said:

It's a 114 + 0.

Ah I thought that might be the case, that explains it

[mikeyb1987]

SturdyHSV said:

7k on stock LS2 bottom end, you'll be fiiiiiiiine, go for it!

6,800 at least, that's barely above idle

That's going to be a whole different car now, can't wait to hear it at Northampton

Ok, if you say so....

I'm going to ask John to temporarily take it up to 6,800- purely as an exercise to see if it still continues to make power. If it does, then next year I'll get some rod bolts, possibly a FAST intake (if needed) and wind it up to 7k.

[mikeyb1987]

SturdyHSV said:

mikeyb1987 said:

Ok, if you say so....

I'm going to ask John to temporarily take it up to 6,800- purely as an exercise to see if it still continues to make power. If it does, then next year I'll get some rod bolts, possibly a FAST intake (if needed) and wind it up to 7k.

The LS3 intake is very good from the factory as I understand it, so although a FAST will most probably give you some gains, they may be very marginal so a lot of £/whp.

Roger said to me 7k is fine, I'm sure he wouldn't want you to take that as a guarantee in your situation, but I'm certainly a bit more comfortable pushing mine having heard that, for what it's worth.

The factory LS3 is very good- so much so that a FAST only really has tangible benefits from circa 4k onwards. I'm just pre-empting the potential inefficiency of the standard intake above 6.6k. I know the cam/heads are good for a few hundred more rpm, so if there are any restrictions in the next chunk of rpm, the bottlenecks are likely to be the intake manifold/filter/MAF.

[mikeyb1987]

All very good points gents. It was only minor musings about a FAST.

I've decided not to push any further re rpm limit until I've had a good chat/debrief with John and AAS. I've reached my goal, and to be honest, I just want to go and drive the car
I'm sure it could do 420rwhp with a few more bolt-ons/lighter pulleys but, for now, I'm happy with what it's done.

[mikeyb1987]

Gelf VXR said:

Nice results, interested to see SRR results for a better comparison, is your cam emmisions friendly?

Are you numbers complete stock before vs after?

Cheers. The cam is described (by both US and Aus guys) as emissions friendly. Plus, Monaro5.7 is running a similar cam in an LS1 and his passed emissions, so I'm confident it is. I'm going to get an emissions test to compare against my MOT, which was pre-cam install.
Before run is with headers, sports cats, catback and OTR intake.

[mikeyb1987]

SturdyHSV said:

Had that been mapped at all?

Nope. Just bolt ons with no tune.

[mikeyb1987]

Well, I'm back home with a cammed V8

My first thoughts mainly surrounded the idle, which is superb.
YouTube link of warm idle:
http://youtu.be/0D40RkQ68H4

Kmud asked about town manners. I will admit that it isn't as town-friendly as a standard car. There's some hesitance and jumpiness but this only happens occasionally. The rest of the time it is extremely well-mannered.
Motorway cruising is on par with a standard car, and above 1,800 rpm the extra urge becomes apparent. It's too early to compare economy (new toys always mean a plummet in mpg!), but based on today (with lots of idling!!) it is roughly 5% less.
Power delivery on full throttle is intoxicating- it just keeps growing and growing all the way to the red line. It was raining/snowing so didn't really get a chance to properly get my toe down. Traction isn't an issue- VXR8 wheels with MPSS tyres matched to a steadily climbing power curve means the tyres are rarely overcome (unless you provoke it) Needless to say I'm hopeful of strong results in the 1/4 and the mile.

Edited by mikeyb1987 on Saturday 29th March 00:25

[mikeyb1987]

MyM8V8 said:

You rarely get a tune right in one hit, ask Ringram, they're never really finished. All depends on how he worked IATs and ECTs down low. Did you go mafless? If you did I might be able to help with that jumpiness. I used a 224-232 114+4 on my 6.0L. The cam was spec'd for L92 heads, although it worked really well stock 243's.

Still got the maf Gareth. I'm sure the tune could be tidied up- John said that if there was anything I wasn't happy about he would try and resolve. Once I've got a few more miles on it I'll go back to him to get it tweaked.

[mikeyb1987]

KMud said:

My lappy speakers are incapable of reproducing those frequencies

As Gareth said, I'd have thought you could improve the manners if you have the means...although there is some joy in the rough edges

That's pretty much the nail on the head, particularly with the idle. It was mentioned that the idle could be increased to make it smoother, but that would have lost some of the lope - it was a big no to that!
I'll get a better video sorted at the weekend, using my gopro.

[mikeyb1987]

wav8 said:

Sounds good Mikey

Cheers Will Maybe between us we can persuade Bob/Roger to get their cars 'tweaked'