When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Thank you for that helpful information. I wasn't aware of the integration, and that I can specify a MAF version from Harrop.
BTW, my raised hood finally arrived from New Zealand so the Hurricane should fit without any interference. I would still solicit your help for a clean tubing transition to the Harrop air/filter intake (post #30 pic-1). Granted, it requires quite a prep work, but you may get the idea.
Yes, the Harrop has the integrated option for the MAP, but the MAF option you can only get with my airboxes. They have 4 inch inlets and can accommodate any 4 inch silicon hose.
Tells me how you have the maf situated, it is not a restriction to the intake. Run a 100-mm card maf to a big cube motor, and it takes up a ton of area, so it acts like an intake restriction. Cool you were able to eliminate that.
Tells me how you have the maf situated, it is not a restriction to the intake. Run a 100-mm card maf to a big cube motor, and it takes up a ton of area, so it acts like an intake restriction. Cool you were able to eliminate that.
Thanks! It was verified with CFD to place the MAF in a location and just poke it in enough into the tube where airflow was clean enough to get a good signal. The two 102mm inlets do help for the reasons you mentioned though, but there was almost no other way to go around that anyways, so it worked out quite well that we're still getting good signal at idle.
such an awesome looking setup. congrats....you did say that there were small stroke ls7s running this up to 8000 rpms? how come the 427 (i think thats your test car displacement) seems to be dropping off pretty fast at 7000?
I would guess the stroke. Typically when I see similar engines tested with similar top ends, I see similar power, edge in torque to the longer stroke, and peak HP while similar is at a higher rpm on the shorter stroke
I see another Maha dyno test!? This one is interesting for me as i can see another comparable dyno sheet, as opposed to the ones in the US where the power figures seem to be so much bigger, you Americans must have some kind of magic air
My graph here is a Kinsler 55mm ITB set up on a 419CI LS3 (4.085x4.00") AFR Cathedral 245 heads.
The lower graph on my one Here is a 454LSX with a Fast 102 on the top.
Damned metric units. At first I thought graph was effed, because the lines don't cross at 5252. LOL.
IMO, 55mm seems small for a 419. I know for my 428, Lance was recommending 65mm. How would you expect throttle size to affect the curves? Carrying even better up top, or possibly raising the torque curve down low?
Damned metric units. At first I thought graph was effed, because the lines don't cross at 5252. LOL.
IMO, 55mm seems small for a 419. I know for my 428, Lance was recommending 65mm. How would you expect throttle size to affect the curves? Carrying even better up top, or possibly raising the torque curve down low?
I am pleased with my results, I don’t think the 55mm chokes are holding this back yet, the 1.75” header, with twin 2.5” pipes might be though, to be honest the thing is pretty dangerous now, throttle response is instant.
On this Maha Dyno I have seen an LSX454 with mast heads and a cam heading upto around 300 exhaust, and big headers twin 3” , plus 60mm ITB set up, that did 680bhp, mine made more torque upto about 4K then it pulled away, not that different to how mine looks against that stock 454lsx I’ve used as a comparison.
Oh yeah, with that if you're anything, it's exhaust limited. Certainly nothing to be disappointed in. I'm sure it's a handful to say the least. Your 0-160 video is impressive. Thanks for the info on the other 454. I think that is pretty much what I was wondering about.
In order to fit a ITB on mine, because F body cowl, the biggest I can go is 58mm, but I'm hearing 65mm is a better match for the motor. So I was curious what your thoughts and experiences were on TB sizing affecting power and performance. I bet that thing does respond quite snappy.
Oh yeah, with that if you're anything, it's exhaust limited. Certainly nothing to be disappointed in. I'm sure it's a handful to say the least. Your 0-160 video is impressive. Thanks for the info on the other 454. I think that is pretty much what I was wondering about.
In order to fit a ITB on mine, because F body cowl, the biggest I can go is 58mm, but I'm hearing 65mm is a better match for the motor. So I was curious what your thoughts and experiences were on TB sizing affecting power and performance. I bet that thing does respond quite snappy.
Nice work man
Thanks, that wild 454 was up around 50bhp from an MSD intake, that 0-160 vid was with a Fast 90 set up, i’ll Bet it’s close on 100bhp more and this now really revs!
Another thing of note mine is not a X over set up, so my runners are shorter, actually the identical length to FAST mid runner, i researched this to get the power band to peak at 7k, and it actually worked, I was quite pleased to find out that Fast agreed with me!
Thanks, that wild 454 was up around 50bhp from an MSD intake, that 0-160 vid was with a Fast 90 set up, i’ll Bet it’s close on 100bhp more and this now really revs!
Another thing of note mine is not a X over set up, so my runners are shorter, actually the identical length to FAST mid runner, i researched this to get the power band to peak at 7k, and it actually worked, I was quite pleased to find out that Fast agreed with me!
Damn that math, it works every time it's used! I'm sort of stuck with X-over due to the "DNF" cowl. But still if you're doing so well with 55mm, I should be fine on 58mm. The fast mid runner IMO is a very good runner length. I do find in the postings and such that the larger engines seem to just respond well to shorter runners, sometimes even at lower RPM. My guess is just raw airspeed with larger cubes means the shortest straw flows the best.
In lots of brackets, ITB is considered a power adder. Guess you're seeing that yourself!
Oh yeah, with that if you're anything, it's exhaust limited. Certainly nothing to be disappointed in. I'm sure it's a handful to say the least. Your 0-160 video is impressive. Thanks for the info on the other 454. I think that is pretty much what I was wondering about.
In order to fit a ITB on mine, because F body cowl, the biggest I can go is 58mm, but I'm hearing 65mm is a better match for the motor. So I was curious what your thoughts and experiences were on TB sizing affecting power and performance. I bet that thing does respond quite snappy.
Damn that math, it works every time it's used! I'm sort of stuck with X-over due to the "DNF" cowl. But still if you're doing so well with 55mm, I should be fine on 58mm. The fast mid runner IMO is a very good runner length. I do find in the postings and such that the larger engines seem to just respond well to shorter runners, sometimes even at lower RPM. My guess is just raw airspeed with larger cubes means the shortest straw flows the best.
In lots of brackets, ITB is considered a power adder. Guess you're seeing that yourself!
I spoke with a guy from Dart heads at a UK show, and he said that the ITB blade must be bigger than the Inlet valve as a rule, so its not the bottle neck. You want a slight smooth taper all the way to the back of the valve in a perfect world, like a rear engined F1 or F5000 car for instance, as straight as possible.
This Macca here is around 900bhp N/A, they said they can get more but its got to go around corners too. I regularly attend events where this competes and it is savage!
But you can do things like this if packaging is no obstacle.
That's really interesting. Given that a well designed intake tract and intake port should have a fairly consistent taper to the valve, it seems like 65mm bores are about the minimum size you should use in an ideal world with a 2.20 intake valve. 65mm is 2.55", and I expect the ITB blade to be ~9 inches from the valve face. The intake port runner length alone is ~5.5 inches.
55mm is 2.165", same as an LS3 valve. A 2.2" LS7 valve will not be happy with that in front of it. I think you'd start seeing intake tract depression like you do with a single plenum intake.
That's really interesting. Given that a well designed intake tract and intake port should have a fairly consistent taper to the valve, it seems like 65mm bores are about the minimum size you should use in an ideal world with a 2.20 intake valve. 65mm is 2.55", and I expect the ITB blade to be ~9 inches from the valve face. The intake port runner length alone is ~5.5 inches.
55mm is 2.165", same as an LS3 valve. A 2.2" LS7 valve will not be happy with that in front of it. I think you'd start seeing intake tract depression like you do with a single plenum intake.
I have a 2.165 valve in my AFR heads, the actual hole in the head would be less than my actual 55mm bore in my Itb's, but yes ideally I think I could do with perhaps a bit more average taper, but on the whole they are doing pretty good. If they were not then i think I would be seeing a big fall off in power at high revs, the fact it only tails off 10bhp from 7-7500rpm I think shows that the sum of the parts quite like each other.
The fact I managed to pack the reversion at exactly where i wanted has more effect at this point i think, I did some dyno back to back with some stack lengths a while back and that was very significant, like 25bhp or so if I remember, if your cam is trying to peak where the pulse wave is not then you are p!ssing in the wind.
ETA, I found the sheet! This was swapping the trumpets nothing else, no fuelling changes just a down and dirty swap and blast just to see. This was my old 416CI motor but the basics still apply.
11-23-2018, 09:24 AM
