ALFAGTV6.COM

SydneyJules · Post by **SydneyJules** » Thu Feb 23, 2006 1:01 pm

Cant be sure, but looks like a Swede's been at it again....

http://www.garaget.org/?car=2965

And i like it!

matt · Post by **matt** » Thu Feb 23, 2006 1:45 pm

Nice!

great to see blow thru carb setups ! ideas, all these turbos with big front mounted intercoolers would they tend to suffer from lag more compared to 75turbo set up with short distance between compressor and plenum? or is lag more dependent on the turbo design itself? fast spool up etc

Mats · Post by **Mats** » Thu Feb 23, 2006 2:33 pm

Of course it's Swedish Jules, wtf did you think...

Currently being rebuilt after a bad headgasket incident though.

la_strega_nera · Post by **la_strega_nera** » Thu Feb 23, 2006 3:05 pm

Oh My... thats gorgeous... i'm almost tempted to sell the XY for one instead of doing another alfetta

GTV6GPTT · Post by **GTV6GPTT** » Wed Mar 08, 2006 9:50 pm

jez, what a nice car. all that work. and its carb.... shame

SydneyJules · Post by **SydneyJules** » Thu Mar 09, 2006 2:07 am

Yeah I know what you're thinking too Ben, Ive considered finding a home for my engine and box, so I can do one, and you too TT... but still, he has managed to keep the flavour of the period.

Still think a TS 105 turbo with all the good suspension stuff on it, a cage and two buckets would whip the bejezus out of all and sundry on a sprint day...

Beninca grouped liners, head porting, big valves, cams with more lift, rods, 7.8:1 comp, GT25 external WG, custom plenum, side pipes, 17s and big brakes.... Like Ive said a gazillion times. I need to earn some money first!

Mats · Post by **Mats** » Thu Mar 09, 2006 5:12 am

Blow through carb work suprisingly well actually, not like a perfect EMS setup naturally but it's not like you lose 50Hp by having carbs...

Jules, do the same on a 116 and you'll blow the doors off of any 105 without "custom everything" in the chassis department.

Greg Gordon · Post by **Greg Gordon** » Thu Mar 09, 2006 5:18 am

That's some car. It's rare to see an old school blow through carb set up. Few people can make those work out well, it takes a serious expert to get one set up right, but blow through carbs are still kicking but at the track in the U.S. In fact the world fastest pump gas car uses blow through carbs.

Matt, turbo lag is a function of both the turbo design, intercooler, piping etc. The current trend among manufacturers seems to be a high compression engine (like around 10:1) with a tiny turbo an intercooler and low boost. Audi and VW do it this way and have essentially no lag. Of course the drawback is the top end horsepower is not what you would expect of a modern intercooled turbo engine.

The lag issue gets to be bigger factor when you have a low compression motor with a lot of boost. Then the motor is weak until the turbo spins up due to the low compression. This is compounded by the extra time the bigger turbo needs to spin up.

Greg Gordon

Greg Gordon · Post by **Greg Gordon** » Thu Mar 09, 2006 10:30 am

Ok...a very sharp fellow just pointed out to me that I need to clarify my last post. My point about low compression is that it will reduce horsepower until the turbo spools up, not that it will increase spool up time.

In other words an otherwise stock 7:1 compression 2.5 will be a real slug until boost kicks in from whatever source, turbo, supercharger, whatever...

Back to the workshop for me.
Greg

matt · Post by **matt** » Thu Mar 09, 2006 11:58 pm

I've blown my budget and planned time it would take to finish this turbo kit

but Jules all that stuff above would cost a serious fortune! Serious Serious HP tho

I think with so many "cheap" 2.0 GTV's in Oz especially on ebay etc you could get a great blow thru turbo project/club car going.
It would be the most "ecconomical HP" too per $, i just wish Alfa Australia imported alfa 75 turbos all those years ago!!!!!!!!!!!!!
3.0 V6 with efi very expensive from wreckers here, prob cheaper to buy 164 for the engine then sell the body/parts to reduce cost but thats just to get a 3.0 engine, let alone start modifing it $$$$, and the cost of bell housing/exhausts/sump/oil pump etc if you have 2.0 4cylinder to start with! plus you wipe another 164 off the planet

A 2.0 blow thru turbo can make more HP for the $............mho

Thanks Greg i'm interested what factors effect lag because 7.1:1 comp ratio(turbodelta)(i haven't driven one myself (yet)) but read Wheels car review from 80's + Barry's white gtv, the turbodelta very tractable, able to pull away low rpm + high gear etc but others say nothing happens till 2500rpm then goes like hell????
So maybe turbo well matched? spins up fast even with low comp pistons, but ultimately too small for big hp. (fit bigger turbo = off boost slug?)+ i suspect such a short distance between turbo/comp and plenum may help vs large front mount air/air intercooler with longer dist/volume etc

Anyone know who's this gtv is? it was on the old site but not much info

matt · Post by **matt** » Fri Mar 10, 2006 12:17 am

some ideas for ben

?????????

2000hp non intercooled blow thru turbo 7.37 @ 194.60

Steve R · Post by **Steve R** » Fri Mar 10, 2006 2:59 am

Needs bigger blowers...

Mats · Post by **Mats** » Fri Mar 10, 2006 3:24 am

Those are not blowers, those are compressors...

Micke · Post by **Micke** » Fri Mar 10, 2006 3:48 am

Whatever HAIRDRYERS....

SydneyJules · Post by **SydneyJules** » Sun Mar 12, 2006 12:42 pm

Hahaha tell me how to get the gearbox to last Mats!!!!

The other function of turbo lag is the piping. The longer the piping the longer the spool up. What Greg is saying about the comp ratio is right- there's not enough "bang" in the engine without the boost for it to work properly, until there is compressor flow, and then they go go go.

But dont under estimate the piping side of things either. Ive said that my friend's 2002 with 6.5:1 static comp had no lag. at about 1/8th throttle in fifth gear it had 7psi boost. Perhaps the shorter gearing (4.27:1, and Getrag close ratio with a 1:1 5th) helped, but Im sure that all of his throttle response was due to the piping, because the comp ratio certainly didnt help.

When he gets on it from a standstill, without stalling it up, the thing snaps sideways to about 30o from straight, and stays there for three gears until he has to stop.

Whatever the drawbacks, it's still the best way to get monster torque from a small cap. engine.

Matt... Im pretty sure those early things kept their 9:1 comp even with boost. It was a stock engine until the boost started adding to the effective comp ratio. You'd only go to the lengths in my other post if you were going to put something like an external wastegated .7x GT25 turbine with a GT30 compressor housing and wheel on the "cold" side. That way you could still spin it to get 30 odd psi boost and have most of it spooled by around 4k rpm. Imagine the torque!?

Exactly!

Hot Little 105 Turbo