turbo charged 3.4 dohc....430 rwhp!

[FerrariFan]

this is a double post since i posted in the 3.4 dohc performance section but I figured not everyone checks out every section and this may be of interest to the boost crowd.

hey guys, I haven't posted in a while but I thought I'd share the latest news from my 355 rebody.
After a custom turbo install and a slipping clutch and some tuning issues I decided to get some help. I took the car to Jeff Ianitello (Engineered Performance) near Atlanta, GA. He installed a Limited Slip Diff in the 282 Getrag and upgraded the clutch to a Spec Stage 3 with an Fidenza aluminum flywheel.
After lot's of chasing vacuum leaks and IAC problems he finally got some serious $8f tuning time in and got her to the dyno.

It makes a solid 430HP at the rear wheels at 12psi with zero knock retard on 91 octane pump gas.
My goal was 380 HP since that's the output of the 355's engine at the crank, anything over that is gravy. Lays a nice double line on the road thanks to the LSD

Here's a link to the dyno graph and some pics of the engine.

http://picasaweb.google.com/103577966960525906703/DropBox?authkey=Gv1sRgCPnLnMu1t_umZg&feat=directlink

[ForcedFirebird]

Google
Error


404 NOT_FOUND
Unable to process request.

[Joseph Upson]

this is a double post since i posted in the 3.4 dohc performance section but I figured not everyone checks out every section and this may be of interest to the boost crowd.

hey guys, I haven't posted in a while but I thought I'd share the latest news from my 355 rebody.
After a custom turbo install and a slipping clutch and some tuning issues I decided to get some help. I took the car to Jeff Ianitello (Engineered Performance) near Atlanta, GA. He installed a Limited Slip Diff in the 282 Getrag and upgraded the clutch to a Spec Stage 3 with an Fidenza aluminum flywheel.
After lot's of chasing vacuum leaks and IAC problems he finally got some serious $8f tuning time in and got her to the dyno.

It makes a solid 430HP at the rear wheels at 12psi with zero knock retard on 91 octane pump gas.
My goal was 380 HP since that's the output of the 355's engine at the crank, anything over that is gravy. Lays a nice double line on the road thanks to the LSD

Here's a link to the dyno graph and some pics of the engine.

http://picasaweb.google.com/10357796...eat=directlink

Very nice work and numbers, I can't believe there's no link to video. What kind of work was done on the engine since clearly there's a lot more potential at only 12 psi, I believe the unofficial goal standard for many aspiring to build an ultimate boosted engine is 15 psi?

[robertisaar]

that is goddamn ridiculous.... then again, i like stupid amounts of power.

[FerrariFan]

Very nice work and numbers, I can't believe there's no link to video. What kind of work was done on the engine since clearly there's a lot more potential at only 12 psi, I believe the unofficial goal standard for many aspiring to build an ultimate boosted engine is 15 psi?

I'm bad about not taking lots of pictures and videos, when I start working on something, I want to get done. the camera and posting slows me down. I'll get some in car vid to post soon though.

As far as work to the engine it's pretty much bone stock internally. That's one reason I didn't want to push it with more boost. When it was at the dyno I was asked if I wanted to go for the "money shot" and bump it up to 15psi, but I thought that I have reached my goal, why push things and risk breaking something. I've just read too many posts about how everything is running great but they keep bumping up the boost for just a bit more power until the last post where you see pics of the big hole the rod punched through the block. I didn't want to be that guy.

As far as parts added, here's what I can remember off the top of my head.

Garrett 32-76R turbo and intercooler
Spec stage 3 clutch
Fidenza aluminum flywheel
custom short runner intake
LS1 throttle body
GM 7727 PCM with $8f
Greddy Profec boost controller
Tial wastegate
Greddy blowoff valve
Innovate wideband
42lb injectors
walbro fuel pump
powersteering delete pulley
undersized pulley

[Mars]

Cool it runs on 8F ! thats awsome, I thought I was the only one left using 2BAR 8F stuff. nice build !

[FerrariFan]

Cool it runs on 8F ! thats awsome, I thought I was the only one left using 2BAR 8F stuff. nice build !

Only one left? You can tell how long ago I started building this thing . What are most of the other turbo's running? $59, Haltech?

[RedZMonte]

8F is TGP code? Im running OBDII on my Turbo LQ1. I use DHP Powertuner to do my tunes (no chip to swap or burn).... MAF based (1 bar map). I think its easier to use on the fly BUT OBDI i think you can do more with.

Again great job, LOVE it.
S

[robertisaar]

$8F is TGP.
$59 is extra-awesome though.

[FerrariFan]

If had known about code 59 a couple of years ago maybe I would have gone that route. I read that it's good for up to 30 psi which is way more than I will ever run. $8f is good up to 15 psi, it is tricky to tune though since there are so many tables, flags and constants to deal with, a lot of them not very well documented. Is anyone here running a turbo 3.4 dohc on $59?

[Joseph Upson]

If had known about code 59 a couple of years ago maybe I would have gone that route. I read that it's good for up to 30 psi which is way more than I will ever run. $8f is good up to 15 psi, it is tricky to tune though since there are so many tables, flags and constants to deal with, a lot of them not very well documented. Is anyone here running a turbo 3.4 dohc on $59?

If you had started with a 730 ecm code 59 would only be a single wire relocation and tuning away. Not sure if it would turn out to be the same with the 727. The difference is a ground for one of the injector banks. I purchased a fancy timing light to help me when I return home, in the effort to switch from 8F to it as there were problems for all who tried to use it with DIS ignition and the few that succeeded with it on DIS in my oppinion have provided little to no appreciable guidance on how they did it. I know of no 60 degree motors running on it at this time.

Whatever the case the problem is setting the proper timing limits in the code so the timing logic does not fault on start up attempts. I believe part of the problem is that the total timing commanded is outside the programmed limits as it relates to the distributor settings due to the considerably reduced timing with the fast burn aluminum heads in some areas of the spark table. Everyone that I'm aware of who tried it with an aluminum head 60 degree V motor had the same results including me. I did succeed at getting the engine to run although poorly for a brief period on my first attempt.

That's what the timing light is for, to help me identify what's going on with the timing as values are being changed in an effort to sort it out. Since I along with at least one other person who attempted it were dealing with the 3900 which has no timing marks for reference and has since been discovered that the VVT camshaft is extreme at full advance and full retard suggesting this may have contributed to the problem as the cam in both engines was fully retarded at the time, and apparently the only reason my engine started was because the camshaft was reground to specs that made it more efficient than the stock specs did fully retarded. The other members engine with the stock cam retarded would not start at all and that explains why despite my success my engine took several attempts and starting fluid for an initial crank and run.

Code59 is very nice and has some impressive add on features.

[FerrariFan]

What code is your VVT engine running? Is it turbocharged?

[Joseph Upson]

What code is your VVT engine running? Is it turbocharged?

8F, yes it's turbocharged

[FerrariFan]

Hi guys,
Thought I'd update you with the latest news. The inevitable has happened and after two years my boosted stock '97 LQ1 finally spun a rod bearing. I had the boost dialed up to 15 psi and may have over-revved it. Bottom line is that I found the limit of what the stock bottom end can handle. Two years ago it dynoed 430 at 12 psi so who knows how much more it was pushing at 15. Now my goal is to pull the engine and build a bullet proof bottom end that can handle 15 psi with no issues. I have a new 95 crate engine that I can use for parts, maybe just the block and crank. (or sell it to pay for parts)
I've been researching forged pistons but haven't found any part numbers or a good source. I know others have ordered custom forged pistons for a boosted engine and I'd like to piggy-back on that so I don't have to start from scratch with dimensions and compression ratios, etc. As far as the crank and rods go does anyone know for sure what the best route to go is? I've read about using the 3500 crank but is is necessary and how much machine work is involved for it to fit?

So far I'm looking at the following:
Forged aluminum pistons with slightly lower compression.
SBC forged performance rods
performance bearings
ARP fasteners for the bottom end and heads
maybe 3500 crank?
What else am I missing?

Thanks,
Lance

[SappySE107]

Did you have ARP rod bolts in before or just a bone stock bottom end? What hp goals do you have now? 3500 crank will need to be turned down on the rod journals, and you will need to deal with the 7x sensor. I personally wouldn't bother with that in a 3.4 DOHC (and I have a 3.4 DOHC). i would add a crank scraper to the list though, since its cheap and well worth the money for something that can spin to 7k+. I have rods and HD bearings in stock, but I do not have pistons for the 3.4 DOHC. I can do 3400 based pistons with a small dish to give you whatever compression ratio you want however.

Other options are the lighter lifters and stiffer comp springs, which i am running in my motor. I replaced the belt just to be sure when I did the cam timing, and the stiffer springs aren't effecting the belt at all.

I already PMed you back about the head studs. I can get measurements on the studs that I think fit but I don't have a carrier here to double check any more. Could have sworn I checked all that before but its been years.