Topcats LS7 Sagaris No2
Topcats LS7 Sagaris No2
Author
Discussion

JLF

Original Poster:

418 posts

222 months

Tuesday 24th September 2013
quotequote all
Well after the engine saga and much deliberation the Sag will be going to Warren at Topcats to be worked on over the winter.

Tough decision until you drive a TVR with the conversion…so big thanks to Simon for letting me drive his Tuscan and for all the advice etc. from a host of people. Simon your car is epic!

After first driving the 350 at Topcats I just knew I wanted that power.......the performance, drivability and pure fun is awesome. Just love the big torque cars and having missed that kind of power when I let my Litchfield GTR go I am now on the way to the very best of all worlds IMO. Even the man maths works .... ish

Loved the S6 just time to go the extra bit.

Now like a kid waiting for Christmasbiggrin

cidergestion

87 posts

198 months

Tuesday 24th September 2013
quotequote all
Fair play keep us updated on progress some pics would be great

7 TVR

2,589 posts

189 months

Tuesday 24th September 2013
quotequote all
Welcome to the Club smile

sonnylad

1,165 posts

246 months

Tuesday 24th September 2013
quotequote all
A great long term choice, worth waiting for.

zeppo

253 posts

211 months

Wednesday 25th September 2013
quotequote all
@JLF
Just a noob question (but maybe affected by the same problem one day)- Why do you choose the LS 7 and not the much cheaper LS3, as it seems that they have nearly the same output-power?
Reliability?


http://shop.partsworldperformance.com/ls7-v8-crate...

http://shop.partsworldperformance.com/ls376-525-v8...

blackiepaul

1,973 posts

215 months

Wednesday 25th September 2013
quotequote all
One has a dry sump and one does not is the main reason.

zeppo said:
@JLF
Just a noob question (but maybe affected by the same problem one day)- Why do you choose the LS 7 and not the much cheaper LS3, as it seems that they have nearly the same output-power?
Reliability?


http://shop.partsworldperformance.com/ls7-v8-crate...

http://shop.partsworldperformance.com/ls376-525-v8...

GTRene

20,620 posts

245 months

Wednesday 25th September 2013
quotequote all
money wise I would also choose for a 480hp or that 525hp LS3 version, I guess more than enough power for the car and reasonable priced.

that said, LS7 sounds a bit cooler and its not my wallet. biggrin

well done and a very nice upgrade, TVR V8 lick

SteveSPG

2,120 posts

223 months

Wednesday 25th September 2013
quotequote all
you might also consider the LSA which also fits. makes more power than the ls7, for similair money.


zeppo

253 posts

211 months

Wednesday 25th September 2013
quotequote all
@Paul
and the few thousand GBP advantage is?

m3coupe

1,116 posts

225 months

Wednesday 25th September 2013
quotequote all
Are the fitting costs the same for both engines or is their more to one than the other?

SteveSPG

2,120 posts

223 months

Wednesday 25th September 2013
quotequote all
zeppo said:
@Paul
and the few thousand GBP advantage is?
dry sump.... 40 hp
better oil control, nil oil starvation,
improved ground clearance
could lower cg of engine (depends on gearbox and bellhousing of course)
ls7 heads flow better than ls3, ultimately higher HP potential
7.0 vs 6.2.....just more cubes to play with, will take a "bigger cam" if thats your thing

blackiepaul

1,973 posts

215 months

Wednesday 25th September 2013
quotequote all
zeppo said:
@Paul
and the few thousand GBP advantage is?
A thew thousand makes no difference when you end up blowing what you do - Steve above got it pretty spot on - worth the money though.

TimJM

1,497 posts

231 months

Wednesday 25th September 2013
quotequote all
SteveSPG said:
zeppo said:
@Paul
and the few thousand GBP advantage is?
dry sump.... 40 hp
better oil control, nil oil starvation,
improved ground clearance
could lower cg of engine (depends on gearbox and bellhousing of course)
ls7 heads flow better than ls3, ultimately higher HP potential
7.0 vs 6.2.....just more cubes to play with, will take a "bigger cam" if thats your thing
All these things can be argued in favour of an LS3 still with some basic mods:
LS7: dry sump.... 40 hp & oil control, nil oil starvation,
LS3: Baffle sump and an accusump

LS7: improved ground clearance could lower cg of engine (depends on gearbox and bellhousing of course)
LS3: Maybe but as you have hinted the bellhousing may be the deciding factor here so may be same for LS3 or 7

LS7: ls7 heads flow better than ls3, ultimately higher HP potential
LS3: stock ls3 heads flow very well from the data I can find they are at around 312 cfm and LS7 at 327 cfm. But you can (with some mods) fit LS7 heads to an LS3 or just port your LS3 heads to beyond LS7 flow rates.

LS7: 7.0 vs 6.2.....just more cubes to play with, will take a "bigger cam" if thats your thing
LS3: Stroker kit

but even with all these arguments the real answer to the first question of 'the few thousand GBP advantage is?' is - it's much cheaper to buy an LS7 than do these things to an LS3.


Don1

16,334 posts

229 months

Wednesday 25th September 2013
quotequote all
Plus it's a fricking LS7!!! biggrin

Great choice, I know you'll enjoy it.

JLF

Original Poster:

418 posts

222 months

Wednesday 25th September 2013
quotequote all
zeppo said:
@JLF
Just a noob question (but maybe affected by the same problem one day)- Why do you choose the LS 7 and not the much cheaper LS3, as it seems that they have nearly the same output-
Good question....The reason I went for the LS7 was simple once I decided against the S6 upgrade. I don't want to start a chain of modifications in order to get more power and I know if I went for the LS3 I would always wonder if the 7 would have been better. I would then start modifying and spend more than the difference on upgrades ....plus the car would spend more time in the garage and less on the road.

The other big reason is I will no doubt do the odd trip to the Ring and enjoy the occasional track day......so I would be modifying an LS3 from day one. 7 does it or me.


Boosted LS1

21,200 posts

281 months

Wednesday 25th September 2013
quotequote all
^ You also get a lot of titanium in an ls7 smile

SteveSPG

2,120 posts

223 months

Wednesday 25th September 2013
quotequote all
JLF said:
zeppo said:
@JLF
Just a noob question (but maybe affected by the same problem one day)- Why do you choose the LS 7 and not the much cheaper LS3, as it seems that they have nearly the same output-
Good question....The reason I went for the LS7 was simple once I decided against the S6 upgrade. I don't want to start a chain of modifications in order to get more power and I know if I went for the LS3 I would always wonder if the 7 would have been better. I would then start modifying and spend more than the difference on upgrades ....plus the car would spend more time in the garage and less on the road.

The other big reason is I will no doubt do the odd trip to the Ring and enjoy the occasional track day......so I would be modifying an LS3 from day one. 7 does it or me.

ive had an ls3 in a cobra replica
later fitted a ls7 block, ls3 heads, wet sump so the only real change was CC

there was no doubting the effect of the extra cubes.........

TimJM

1,497 posts

231 months

Wednesday 25th September 2013
quotequote all
Based on the "well it only costs X amount more" would the ls9 fit?

Look at this comparative graph, the torque curve from ls3 to ls7 is noticeable sure but the ls7 to ls9 increase is insane!

spartridge

970 posts

231 months

Wednesday 25th September 2013
quotequote all
Good man wink

When is it going in?

spartridge

970 posts

231 months

Wednesday 25th September 2013
quotequote all
Good man wink

When is it going in?